360° Depth Estimation

360° videos provide an immersive environment for people to engage, and Taiwan Traveler is a smart online tourism platform that utilizes 360° panoramic views to realize virtual sightseeing experiences. To immerse users in the virtual world, we aim to exploit depth information to provide a sense of space, enabling tourists to better explore scenic attractions.

 

Introduction

Depth plays a pivotal role in helping users to perceive 3D space from 2D images. With the depth information, it is possible to provide users with more cues about the sense of 3D space via 2D perspective images. For example, a disparity map can be derived from the depth map, and it is possible to create stereo vision. Also, the surface normals can be inferred by the depth map for better shape understanding. By warping the cursor according to depth and surface normals, users can experience the scene geometry better through hovering over the images.

Depth estimation of perspective images is a well-studied task in computer vision, and deep learning has significantly improved its accuracy. Trained with large datasets containing ground-truth depth information, the estimation models learn to predict the 3D scene geometry by merely using 2D images. However, the depth estimation of 360° images is knotty. The estimation model’s ability is often limited to indoor environments because of the lack of datasets for outdoor scenes. In addition, the distortion on an equirectangular image makes the problem difficult to tackle with convolution neural networks. Thus, predicting accurate 360° depth maps from images is still a challenging task. 

In this project, given a single 360° image, we aim at estimating a 360° depth map, by which we can calculate the surface normals, allowing users to hover the scenes by moving mouses over images. To obtain depth maps that can achieve a satisfactory user experience, we utilize single-image depth estimation models designed for perspective images. For adapting these models to 360° images, our method blends depth information from different sampled perspective views to output a spatially consistent 360° depth map.

 

Existing Methods

Monocular depth estimation refers to the task that predicts scene depth from a single image. Recently, deep learning has been exploited to cope with this challenging task and has shown compelling results. Through a large amount of data, the neural network can learn to infer per-pixel depth value, thus constructing a complete depth map.

Currently, 360° depth estimation is more mature for indoor scenes than outdoor ones. There are a few reasons. First, it is more challenging to collect ground-truth depth for 360° images, and most existing models rely on synthetic data of indoor scenes. Second, current models often leverage structures and prior knowledge of indoor scenes. Our online intelligent tour system contains a large number of outdoor scenic attractions, along with indoor scenes. Thus, existing models for indoor settings do not apply to our applications. 

 

Our Method

In order to take advantage of the more mature monocular depth estimation for perspective images, our method first converts equirectangular images to perspective images. A common way is to project a spherical 360° image onto a six-face cubemap. Each face of the cubemap represents a part of the 360° image through projection. After converting a 360° image to several perspective images, a depth estimation model for perspective images, such as the one proposed by Ranftl et al. [1] can be applied. These models often extract features from these NFOV (normal-field-of-view) images and predict depth maps.

After obtaining the depth maps for NFOV images, the next step is to fuse those depth maps into a 360° depth map. For the fusion task, we have to deal with the following issues. 

1. Objects across different NFOV images

When projecting the 360° spherical image onto different tangent planes, some objects could be divided into parts. The segmented parts can not be recognized well by the estimation model and could be predicted with inaccurate depth. Besides, the same objects across different planes could lead to depth inconsistency when assembling the parts, leading to apparent seams.

 

2. Depth scale

In a perspective depth map, though the relative depth relationship between objects is roughly correct, the depth gradient may be drastically large, e.g., a decoration on a wall or a surfboard on the water. The distinct color and texture between nearby objects would cause dramatically different depth values even if they are almost on the same plane.

Their depth scales could be different between multiple perspective depth maps, making it difficult to fuse them to a 360° depth map. Though we can adjust their depth scales to match neighboring images globally by overlapping areas, it’s challenging to adjust objects’ depth values locally. In addition, a depth map is adjacent to multiple depth maps. Thus, we need to solve for globally optimal scaling factors.

 

3. Wrong estimation of vertical faces

Most of the training data for the depth estimation model are captured from normal viewing angles. The datasets lack images looking towards the top (e.g., sky and ceiling) or bottom (e.g., ground and floor) of the scenes. Thus, the learned models often cannot learn to predict the accurate depth maps for those views. Usually, the surrounding area of a horizontal perspective image is closer to the camera, while the center area is often deeper than other regions. In contrast, the center area of top/bottom views is often closer to the camera, and other regions are farther away. Thus, depth estimation of the top/bottom views is often less accurate as the wrong prior is used.

 

Figure 1: top-left: 360° image, bottom-left: cubemap images, bottom-right: cubemap depth maps, top-right: fused 360° depth map with seams.

 

Due to the aforementioned issues, a 360° depth map often suffers from apparent seams along the boundaries of depth maps after fusion. Our method first converts 360° images to cubemaps with a FOV (field-of-view) larger than 90 degrees. It guarantees the overlaps between adjacent faces. After that, the estimation model predicts the depth map for each image. We then project each perspective depth map to a spherical surface and apply equirectangular projection for manipulating them on a two-dimensional plane. To avoid dramatic change between depth maps, we adjust their values according to the overlapping area. Then we apply Poisson Blending [2] to compose them in the gradient domain. The depth gradients guide the values around the boundaries and propagate inside, retaining the relative depth and eliminating seams. Therefore, the depth values smoothly change across depth maps.

Additionally, we utilize different strategies to divide a 360° image into several perspective images. Apart from the standard cubemap projection, our method utilizes two approaches to divide images and combine perspective depth maps. 

The first approach is to use a polyhedron to approximate a spherical image. When projecting a 360° image to a tangent plane, the peripheral regions are distorted, affecting the depth estimation, especially when FOV is large. By projecting the spherical surface to multiple faces (more than 20 faces), we better approximate a sphere with a polyhedron to obtain less distorted features. Nevertheless, adopting appropriate criteria to select and blend those depth maps is crucial. When having more depth maps to blend, adjusting their depth scales becomes difficult. Also, seamlessly blending images creates gradual depth change along the boundary, acting like a smoothing operation. With more blending iterations for the depth maps, smoothing all the boundaries between them generates blurring artifacts. Choosing the proper part of depth maps and designing the process to fuse them is essential.

The second approach is opposite to the previous one, using fewer depth maps to blend. As mentioned earlier, the estimation model cannot tackle the vertical faces on the top and bottom. Therefore, even if the boundary between vertical and horizontal faces is smooth, the predicted vertical depth maps’ gradient still contradicts our perception of real-world space. As such, we only predict the depth maps of horizontal perspective images and exploit them to generate a 360° depth map. We expand their FOV to obtain more information and increase overlapping. Besides, the vertical perspective region is naturally sky, roof, and floor, etc. Utilizing the assumption that it’s often a smooth area without texture and depth change, we fill the areas with a smooth gradient field and blend them into the horizontal areas. Since the vertical region, the high latitude area of an equirectangular map, only corresponds to a small area on the sphere, this artificial filled-up region doesn’t harm the 360° depth map much. Instead, it creates better depth maps for the hovering experience. This method naturally fuses horizontal depth maps and vertical smooth fields to generate a spatial-consistent 360° depth map and allow users to explore the three-dimensional space.

Figure 2: Left: Equirectangular image, Right: Equirectangular depth map generated from horizontal perspective images of the left image.

 

Except for the method mentioned above, we discuss the next step of 360° depth estimation. Taiwan Traveler uses 360° videos to create virtual tours, and it is possible to exploit the temporal information conveyed in videos to have a more accurate depth estimation. Adjacent frames taken from different camera views comply with geometry constraints. Thus, we could exploit a neural network to estimate the camera motion, object motion, and scene depth simultaneously. With this information, we can calculate the pixel reprojection error as supervision signals to train the estimation model. This self-supervised learning framework can tackle the problem of lacking 360° outdoor depth map datasets and has proved its feasibility for depth estimation from perspective videos. As a result, unsupervised depth estimation from 360° videos is worth researching in the future.

 

Conclusion

We exploit deep learning’s capability and design a process to fuse perspective depth maps into a 360° depth map. We tackle the current limitation of 360° scene depth estimation and construct scene geometry for a better sense of space. This method could benefit the online 360° virtual tours and elevate users’ experience of perceiving space in the virtual environment.

Figure 3: Users can hover over the image for exploring the scene, with the cursor icon warped according to the depth and surface normal at the pixel underneath the cursor.

 

Reference

[1] Ranftl, R., Lasinger, K., Hafner, D., Schindler, K., & Koltun, V. (2019). Towards robust monocular depth estimation: Mixing datasets for zero-shot cross-dataset transfer. arXiv preprint arXiv:1907.01341.

[2] Pérez, P., Gangnet, M., & Blake, A. (2003). Poisson image editing. In ACM SIGGRAPH 2003 Papers (pp. 313-318).

The Magic to Disappear Cameraman: Removing Object from 8K 360° Videos

360° video, also known as immersive video, has been increasingly popular and drawn great attention nowadays since it unlocks unlimited possibilities for content creators and encourages viewer engagement. One representative application which exploits the power of 360° videos is Taiwan Traveler. Taiwan Traveler, Taiwan’s first smart tourism platform developed by Taiwan AI Labs, aims to use 360° videos to create immersive experiences for viewers by inviting them on a virtual journey to different scenic attractions in Taiwan.    While 360° videos have plenty of advantages, there are some challenging tasks to be solved. One of the most critical drawbacks that hinder the user experience in 360° videos is the presence of the cameraman in the film. Since 360° videos capture views in every direction, there is no place for cameramen to hide. To alleviate this problem, we developed a cameraman removal algorithm by modifying existing video object segmentation and video inpainting methods to automatically remove the cameraman in 360° videos and thus enhance the visual quality.

 

Overview of Existing Methods

Removing unwanted objects in videos (video object removal) is a practical yet challenging task. There are two main methods to handle video object removal tasks. The first one is to manually edit every single frame by image-based object removal tools while the other one automatically edits the whole video by video object removal tools.

 

Manual Editing Single-Frame

There have been many image object removal tools such as healing brush, patch tool, and clone stamp tool, etc. However,  it is difficult to extend these techniques to videos. Directly applying image object removal techniques to each frame of a video fails since it does not take temporal consistency into account. That is, although image object removal methods can hallucinate plausible content for each frame, the inconsistent hallucinated content between frames can be easily spotted by human eyes, and thus lead to poor user experience. To maintain video temporal consistency, the post-production crew needs to go through each frame and manually replace the unwanted objects with plausible content without breaking temporal consistency, which is both time-consuming and labor-intensive to achieve a good result.

 

Automatic Video Object Removal Approaches

Recently, Content-Aware Fill introduced by Adobe After Effects in 2019 is the most relevant feature of automatically removing unwanted objects in videos that we could find on the market. Nonetheless, Content-Aware Fill requires manually annotated masks for keyframes, and it can only produce good results while dealing with relatively small objects. Also, the processing speed of Content-Aware Fill is so slow that it is only recommended to be applied to short-term videos. To remove the cameraman in a long-term 360° video with little human effort, we proposed a cameraman removal algorithm that can automatically remove the cameraman in a given video with only “one” annotation mask required.

 

Our Methods

 Figure 1: left: original image, middle: video masks generation result image, right: video inpainting result image.

 

In this task, our goal is to keep track of the cameraman in a video and replace the cameraman in each frame with plausible background textures in a temporally consistent manner. To achieve our goal, we separate this task into two main parts: 1) Video Masks Generation, and 2) Video Inpainting, where the first part aims to generate the mask of the cameraman in each frame, and the second part is responsible for filling in background textures to the masked region coherently.

Rotate Cameraman Up to Avoid Distortion Problem

Figure 2: top: equirectangular frame, down: rotated equirectangular (rotate up by 90°) frame. The red dotted lines refer to the regions of the cameraman to be removed.

 

Before introducing the methodologies in Video Masks Generation and Video Inpainting, it is noteworthy to mention that we performed a small trick on our video frames to bypass the distortion problem in equirectangular projection. As shown in Figure 2., the left image refers to the equirectangular projection of a frame in a 360° video, where we can see the cameraman in the frame is highly distorted. Distorted objects are extremely hard to be dealt with since most modern convolutional neural networks (CNNs) are designed for NFOV (normal field of view) images with no distorted objects in them. To mitigate this problem, we first project the equirectangular frame to a unit sphere, then we rotate the sphere up by 90° along the longitude and project it back to equirectangular projection. We refer the results of this transformation to rotated equirectangular frames. As shown in Figure 2. (right), the cameraman in the rotated equirectangular frame has almost no distortion, so that we can apply convolutional neural networks to it effectively. 

By transforming equirectangular frames into rotated equirectangular frames, we not only eliminate cameraman distortion but simplify the following video processing steps. Let us introduce the methodologies behind Video Masks Generation and Video Inpainting.

Video Mask Generation

Figure 3: video masks generation result image.

 

To generate masks for cameramen, a video object segmentation algorithm proposed by Yang et al. [1] is applied. Given a specific frame’s manually annotated mask of the cameraman in the video, this algorithm will automatically keep track of the cameraman and generate accurate cameraman’s masks for the rest of the frames in the video. 

 

While the algorithm works well in most cases, we observed three scenarios in which the video masks generation algorithm fails: cameraman’s feet appear from time to time, harsh lighting conditions, and similar appearance between background and cameraman’s clothing. In the first scenario, the cameraman’s feet do not always appear in every frame, hence it is difficult for our model to keep track of the feet. In the second scenario, harsh lighting conditions can drastically change the pixel values of the cameraman, which can cause inaccurate feature extractions and further affect the mask prediction. Lastly, in the third scenario, when the appearance of the cameraman’s clothing looks too similar to the background texture, it confuses our model, and it results in our model regarding a portion of the cameraman as the background.

 

Figure 4: failure cases in video masks generation. left: exposed cameraman’s feet, middle: harsh lighting condition, right: similar appearance between cameraman’s clothing and the background.

 

Video Inpainting

Figure 5: video inpainting result image.

 

As for video inpainting, we attempted to fill high-resolution content into the masked region with temporal consistency considered. Many trials have been made to overcome this challenging task. Applying image inpainting independently on each frame fails due to temporal inconsistency, and non-optical flow-based video inpainting approaches fail because of low resolution/blurry outcomes. The most convincing method is FGVC [2], an optical flow-based video inpainting algorithm that obtains the correlation between pixels in neighboring frames by calculating the optical flow between every two consecutive frames bidirectionally. By leveraging the information of pixel correlations, FGVC can fill the masked region by propagating pixels from the unmasked regions, which produces high resolution, temporal consistent results by nature.

 

However, there are two fatal issues in FGVC that prevent us from applying the algorithm to our videos directly. The first issue is the processing speed. Although the algorithm can process high-resolution input, it costs lots of time to finish one video, which is an infeasible approach if we still have lots of videos waiting in line. The second issue is that FGVC cannot handle long-duration videos due to limited CPU resources. The algorithm needs to store all the flow maps in a video into CPU memory, so there is a good chance that the computers run out of CPU memory if the video is too long.

 

Figure 6: Flow map comparison before and after removing the cameraman. left: original frame, middle: flow map of the original frame with the cameraman in it (the purple region indicates the cameraman’s flow is different from the background’s flow in green), right: completed flow map after removing the cameraman (fill the cameraman region with the smooth flow).

 

Figure 7: Comparison of cameraman removal results with and without Poison blending. left: original frame, middle: cameraman removal without Poisson blending, right: cameraman removal with Poisson blending.

 

To cope with the above issues, we made the following tweaks to the algorithm. 

For the performance part, first, we only calculate the flow maps on a cropped, downsampled patch of each frame since the cameraman always locates around the middle of a frame. Second, after removing the cameraman’s flow in each flow map, we downsample each flow map again before completing the missing flow with the background flow. This is because we expect the background flow to be smooth and therefore won’t be affected by downsampling (Figure 6). Third, we removed the Poisson blending operation which costs lots of processing time in solving the optimization problem. Instead, we reconstruct the missing regions by directly propagating pixel values from the predicted flow maps, which can save lots of time with no obvious quality difference compared to the Poisson blending approach  (Figure 7). Lastly, since we only reconstruct the missing regions in a cropped, downsampled patch of each frame, a super-resolution model [3] is used to upsample the inpainted patch back to high resolution without losing much visual quality. 

 

As for the second issue, we developed a dynamic video slicing algorithm to fit hardware memory limits while ensuring video temporal consistency. The dynamic video slicing algorithm can dynamically schedule a slice of frames in a video at a time so that the entire inpainting process can run smoothly without running out of hardware memory. To ensure video temporal consistency between two consecutive slices, we use the last few inpainted frames as the guidance of the next slice. Therefore, the inpainting process in the next slice can make use of the inpainted regions’ information in the guidance frames to generate temporal consistent results with the previous slice. The slicing algorithm also makes sure the number of frames in each slice is the same so that the quality of each slice can stay consistent.

 

In addition to the adjustments we made mentioned above, we fixed an error of the algorithm taking the wrong masks during pixel reconstruction, which results in mistaken border pixels. By virtue of these modifications, our algorithm can now process an 8K long-term video with only one Nvidia 2080 Ti GPU while holding decent running speed.

 

Results

 

Figure 8: up: original frame (the cameraman in the frame is outlined by the red dotted line), down: cameraman removed frame.

 

Figure 8. shows the comparison of a frame before and after applying cameraman removal. As we can see, the cameraman together with its shadow in the bottom part of the frame is completely removed and filled with plausible background textures. The result significantly improves the video quality and thus brings unprecedented immersive experiences to viewers.

Figure 9: left: color shading, right: bad tracking result causes poor inpainting outcome (see the tracking result in Figure 4.-right).

 

Apart from the compelling results shown above, we discuss two potential issues of our cameraman removal algorithm: color shading and poor inpainting outcomes caused by bad tracking results. The color shading problem occurs since we fill the cameraman region by borrowing pixel “colors” from different frames with different lighting conditions using pixel correlations. Therefore, the brightness of the pixels we borrowed cannot fuse seamlessly. As for poor inpainting outcomes caused by bad tracking results, the problem happens due to the inaccurate masks generated in video mask generation. If the mask does not fully cover the cameraman in a frame, the exposed part of the cameraman may prevent us from obtaining accurate pixel correlations, which further harms the inpainting process and leads to unreliable inpainting results.

Conclusions

Our cameraman removal algorithm shows that deep learning models are capable of dealing with 360° high-resolution long-term videos, where each of these three properties can be one difficult computer vision task on its own. By applying some modifications to existing video mask generation and video inpainting methods, we can achieve compelling results. This algorithm can save tons of human labor, which traditionally takes several days for an annotator to remove the cameraman in just one video. Also, the algorithm is robust enough to be applied to real-world 360° virtual tour videos and generate pleasurable high-quality results. (see more results on Taiwan Traveler’s official website: https://tter.cc)

References

[1] Yang, Z., Wei, Y., & Yang, Y. (2020). Collaborative video object segmentation by foreground-background integration. In Proceedings of the European Conference on Computer Vision.

[2] Gao, C., Saraf, A., Huang, J.B., & Kopf, J. (2020). Flow-edge Guided Video Completion. In European Conference on Computer Vision.

[3] Wang, X., Yu, K., Wu, S., Gu, J., Liu, Y., Dong, C., Qiao, Y., & Loy, C. (2018). ESRGAN: Enhanced super-resolution generative adversarial networks. In The European Conference on Computer Vision Workshops (ECCVW).

Label360: An Annotation Interface for Labeling Instance-Aware Semantic Labels on Panoramic Full Images

Deep convolution neural networks have received great success due to the availability of large scale datasets, such as ImageNet[1], PASCAL VOC[2], COCO[3], and Cityscapes[4], but most of these datasets only contain normal-field-of-view (NFOV) images. Although spherical images have been widely used in virtual reality, real estate and autonomous driving, there is still a lack of accurate and efficient spherical image annotation tools to create a large set of labeled spherical images that can help train instance-aware segmentation models. Therefore, we developed an innovative annotation tool Label360v2 (Figure 1) to help annotators label spherical images (Figure 2). fast and precisely. We also introduced
a post-processing algorithm that generates the distortion-free spherical annotation masks on equirectangular image. Label360v2 and annotated aerial 360 dataset are available to the public here. (https://github.com/ailabstw/label360)

Figure 1

 

Figure 2

 

System Design
Annotating a spherical image in equirectangular projection with a standard labeling tool, e.g., LabelMe, directly will have upper and bottom parts of the spherical image suffer from distortion, making the instances difficult to recognize and annotate. Moreover, splitting a spherical image into several NFOV images first before labeling will create instance matching issues if there is an overlapping instance in more than one NFOV image.
To solve these issues, our Label360v2 displays spherical images by rectilinear projection, which eliminates the distortion issue and helps annotators gain a better understanding of the image content. The annotators can also change the viewing direction and the field-of-view arbitrarily during annotation. This helps users annotate instances of any size or at any position.
Besides the features mentioned above, Label360v2 is easy for novices to learn. The annotation process has two main steps: 1) Define class names and assign colors in the class management panel. 2) To annotate a new instance, select an annotation class first and click along the target boundary or an edge in the NFOV viewer to form a polygon. To edit an existing polygon, select it in the data panel or in the NFOV viewer to view all the vertices. A user could add, move, or delete a vertex. To delete an existing polygon, click the trash can button in the data panel.
After the annotation process is completed, our post-processing algorithm generates the spherical annotation masks Fig1. by connecting the vertices using the arcs of the great circle instead of straight lines. It greatly reduces the distortion of the annotation masks, especially when the masks are rendered to an equirectangular image.

Experiments
Two annotators were asked to label 7 classes (Figure 3) on 20 different spherical images using the Label360 tool. We found that they yielded similar results where every class had the mean intersection over union (mIoU) 0.75 (Figure 4). We then asked one annotator to label the same images again using LabelMe[5] instead. Label360v2 took about 83 minutes per image, whereas LabelMe took about 134 minutes (Figure 5) This means the annotation speed of labeling using Label360v2 is around 1.45x annotation speed of LabelMe.
The annotations labeled with LabelMe have more vertices than with Label360v2 because most straight lines in NFOV are distorted into curves in spherical images, and so it requires more vertices to fit the curved boundaries. Moreover, the upper and bottom parts of the panorama suffer from great distortion, which adds to the complexity of the annotation task.

Figure 3

Figure 4

Figure 5

Conclusion

Label360 helps annotators label spherical images in an efficient and precise manner, which reduces a lot of human effort. Also, the post-processing method we provided generates distortion-free pixel-wise labeling masks of spherical images.

 

Reference

1. J. Deng, W. Dong, R. Socher, L.-J. Li, K. Li, and L. Fei-Fei. 2009. ImageNet: A Large- Scale Hierarchical Image Database. In CVPR09. Institute of Electrical and Electron- ics Engineers (IEEE), Miami, Florida, USA., 248–255.
2. Everingham, Van Gool M., Williams L., C. K. I., J. Winn, and A. Zisserman. 2010. The Pascal Visual Object Classes (VOC) Challenge. International Journal of Computer Vision 88, 2 (June 2010), 303–338.
3. Tsung-Yi Lin, Michael Maire, Serge Belongie, James Hays, Pietro Perona, Deva Ra- manan, Piotr Dollár, and C Lawrence Zitnick. 2014. Microsoft coco: Common objects in context. In European conference on computer vision. Springer, Springer, Zurich, Switzerland, 740–755.
4. Marius Cordts, Mohamed Omran, Sebastian Ramos, Timo Rehfeld, Markus Enzweiler, Rodrigo Benenson, Uwe Franke, Stefan Roth, and Bernt Schiele. 2016. The cityscapes dataset for semantic urban scene understanding. In Proceedings of the IEEE conference on computer vision and pattern recognition. Institute of Electrical and Electronics Engineers (IEEE), Caesars Palace, Las Vegas, Nevada, United States, 3213–3223.
5. Bryan C Russell, Antonio Torralba, Kevin P Murphy, and William T Freeman. 2008. La- belMe: a database and web-based tool for image annotation. International Journal of Computer Vision 77, 1-3 (2008), 157–173.

The World’s First 360° AI Aerial Transportation Management


FREEWAY FILM
A documentary highlighting locations along Highway No. 61, expected to be completed by the end of next year, uses artificial intelligence (AI) to  create the rest of the footage in Chi Po-Lin’s style.

Date: October 28, 2019

Taiwan AI Labs and the Directorate-General of Highways are to release a short film highlighting popular spots and cultural activities along Provincial Highway No. 61 together, the agency announced on  press conference.

The film was produced in collaboration with the Chi Po-Lin Foundation.

“The Ministry of Communications and Transportation hopes to remake the image of the highway, which has been called the “poor man’s highway” due to the absence of toll stations, into one in which travelers would be able to admire the beauty of Taiwan’s coastline, Minister of Transportation and Communications, ”Lin Chia-lung (林佳龍) said.

“The ministry hopes travelers will be encouraged to stop at sites along the highway to learn about the history and culture of local areas,”said Lin .

Humanity, Privacy, Integrity – Taiwan’s Unique Smart Cities Approach

Chi once stated that he did not use “drones,” because drones could not automatically choose shots or move the camera, and were therefore unable to produce high-quality video. With this in mind, AI Labs gave AI a chance to learn from Director Chi’s films, teaching the AI about his aesthetics of scene selection.

“ Taiwan AI Labs will collaborate with the Ministry of Communications and Transportation by using artificial intelligence (AI) to create the rest of the footage in Chi’s style,”said Ethan TU .

Smart cities should give people more convenient access to care, while at the same time making them feel confident about disclosing their personal information without having to worry about their privacy being compromised.

(From right, Taiwan AI Labs founder Ethan Tu , Minster of Transportation and Communications Lin Chia-lung, Chi Po-Lin Foundation chief executive Wan Kuan-li and others attend a news conference in Taipei on press conference announcing the release of a short film promoting Provincial Highway No. 61.)

Highway No. 61

Highway No. 61, also known as the West Coast Highway, which runs from New Taipei City’s Bali District (八里) to Qigu District (七股) in Tainan, has been under construction since 1991. It is expected to be completed by the end of the year.

Half of the footage in the new film is from documentary maker Chi Po-lin’s (齊柏林) acclaimed 2013 Beyond Beauty — Taiwan From Above (看見台灣), which showcased the diversity of Taiwan through aerial photography, but also highlighted environmental damage from urbanization and pollution.

“Chi’s documentary helped turn public attention to ecological and environmental conservation, and his efforts should serve as a model for civil servants,” the agency said.





 

 

The Moonscape World Project

Designing an immersive tourism experience, using game elements and aerial cinematography

In the beginning of June, Taiwan AI Labs released a demonstration of how aerial footage collected by a drone, combined with artificial intelligence and video processing, can be used to create a flight simulation based on a spontaneous user-defined starting and ending point. While users are restricted to clicking on points within National Taiwan University’s campus, following feedback from the demo, the Smart City Team ascertained that we have the necessary backend technology to make something out of drone aerial footage that is novel and cool for users.

Different from other ubiquitous map tools, e.g., Google Maps, the team’s demo promises users a different perspective, rising high above to what Michel De Certeau calls the “the threshold of visibility.” The NTU demo serves as a proof of concept. By elevating the plane from which a user sees, the user leaves the messiness and chaos of the city behind, transforming his or her perspective from those of an average citizen to what some refer to as the totalizing eye. The user sees the city, such a familiar construct, under an entirely different light.

 

However, the team also found that users longed for a little bit more interactivity. For the next demonstration, our goal is to use the technology that we have built already–with just one alteration. The team aims to build a narrative around the existing infrastructure; by playing around with story and game elements, along with designing an interesting narrative, we want to bring to life an immersive tourism experience. And thus, the Moonscape World Project was born.

This new direction led to the demand of numerous elements and assets, including text, art, visuals, sounds, and music. Somehow, I became the person that overlooked the early development process of the narrative and prototyping the interactive experience. The narrative itself took a lot of mulling over. The story arcs need to be simultaneously interesting enough to keep the users’ attention, while not straying entirely into the world of fantasy because there needed to be some aspects that a user would be able to relate to were they actually going to Tainan Moonscape Park. My first draft was about an astronaut who crashed on an unknown planet, and met with all these weird creatures on his/her journey. That turned out to be too much fantasy and too little realism, so I tried to incorporate factual information into the script that could serve educational and tourism purposes a little bit better. No longer was the story completely being imagined from my head. It was the actual stories of the people, of the land, and of the history, just told from a different world setting.

Then came prototyping the written narrative into my first digital prototype. Since everyone had such unique and different takes on what the experience should be like, it was hard to agree on all the tiny details during early development. To showcase my thoughts, I would attempt to make my ideas into concrete prototypes that would be used to convey experiences. As different ideas emerged, new prototypes were made to test the viability of the new concept. I was pleasantly surprised by how AI pops up in places that I didn’t expect, in the forms of sky replacement in the scenery, style transfers to make the backgrounds and foregrounds more coherent, and image detection that could be used as a trigger to story events.In the last two weeks, I started spending more time on drawing and animating in order to create a more visually refined prototype, and on redesigning the game engine such that it respected modularity. That means making a creative tool that future story writers and filmmakers could use without needing to know how to code.

I’m ending on a quote that refers, aptly, to the moon. Mark Twain once said, “Everyone is a moon, and has a dark side which he never shows to anybody.” If there is to be one secret that I kept during my internship at Taiwan AI Labs, it’s not that I never did feel like a hardcore software engineer, because in no way do I hold myself accountable for this happy accident. Instead, here is my secret. The work I did wasn’t entirely what I expected when I first came in, but I freaking loved every moment of it.

Label360: An Implementation of a 360 Segmentation Labelling Tool

The image above shows an example of the segmentation mask overlaying on top of the 360 image we got from our drone. This image is labeled by one of our in-house labelers. 

 

Semantic segmentation is one of the key problems in computer vision. It is important for image analysis tasks, and it paves the way towards scene understanding. Semantic segmentation refers to the process of assigning each pixel of the image with a class label, such as sky, road, or person. There are numerous applications that nourish from inferring knowledge from imagery. Some applications include self-driving vehicles, human-computer interaction, and virtual reality. 

360 images and videos are popular nowadays for applications like game design, surveillance systems, and virtual tourism. Researchers use 360 images as input for object detection and semantic segmentation models. However,  researchers usually convert 360 images to normal field-of-view first before labelling them. For example, Stanford 2D-3D-Semantics Dataset has 360 images, but the segmentation datasets are sampled images from equirectangular projection with different field-of-views  [1]. Other 360 datasets only have labeled saliency but not segmentation, such as Salient360 and video saliency dataset [2][3]. Lastly, there are 360 datasets with many equirectangular images, but they are not yet labeled, such as Pano2Vid and Sports360 [4][5]. 

To our knowledge, there are no public annotation tools that are suitable for 360 images, and so we decided to build a semantic segmentation annotator from the ground up that is specifically for 360 images, hoping to increase the amount of research relating to semantic segmentation on equirectangular images. 

The first problem with labelling 360 images is that it is difficult to label and recognize objects at the top and bottom of the equirectangular images. This is because when spherical surface projects to a plane, the top and bottom of the sphere gets stretched to the width of the image. 

Converting to cubemap solves that problem but raises another:  Objects that span across two faces of the cube are harder to label. To deal with the two problems above, we use cubemap and provide drawing canvas with expanded field-of-view. We will describe these methods in detail later on. 

 

Our 360 segmentation tool

UI Components: 

  1. Toolbar: It has plotting, editing, zooming, and undoing functions.
  2. Drawing canvas: The user can annotate on the drawing canvas. The canvas displays a face of the cubemap with an expanded field-of-view. 
  3. Cubemap viewer: The user can select a face in the cubemap to annotate and view annotations in cubemap. 
  4. Image navigator: The user can navigate to different images.
  5. Equirectangular viewer: The user can see mapped annotations in equirectangular view in real-time.
  6. Class selector: The user can view annotations of different classes.

In the cubemap viewer, the border color of the faces in the cubemap canvas indicates the status of the annotations:  Faces with existing annotations are indicated using a green border, and those without using a red border. The current face shown in draw canvas is indicated in yellow. We will describe drawing canvas in detail later on. 

User journey:

Annotation Process:

The flow chart below shows the annotation process from equirectangular image to the input to the semantic segmentation model. 

Design:

  • The use of cubemap solves the problem of distortion at the top and bottom of 360 images 

The main difference between 360 images and normal field-of-view images is that the top and bottom of 360 images are distorted. This distortion results from points near the top and bottom of the images being stretched to fit the full width of the image. If we directly place the equirectangular image into a widely used annotation tool, it is difficult to label the top and bottom of the image. Moreover, it is harder and more time consuming to label the curves at those areas using polygons.  

To make it easier to recognize and label equirectangular images, we designed our annotator to display cubemaps instead. The image below shows the conversion between a cubemap (left) and an equirectangular image (right). 

By converting the equirectangular image to a cubemap, we allow annotators to see objects in a normal field-of-view. In addition, we allow users to annotate each side of the cubemap separately. Below shows our original image (right) and the cubemap we convert to (left). 

   

 

  • Annotation on an expanded field-of-view and real-time display of equirectangular annotations solve the border problem

As we developed the segmentation annotator, we found out that the borders between faces of the cube have gaps or do not appear connected. This may cause a problem because a road that crosses several sides of the cube may be discontinuous. Moreover, it is difficult to draw near the borders. The annotator has  to spend a lot of time adjusting the points to the borders. 

  

Images above show our method of dealing with the border problem. The drawing canvas has a 100 degree field-of-view on one face of the cube. The yellow square inside the drawing canvas has a 90 degree field-of-view. Annotators can label objects in the expanded field-of-view, but only the annotations inside the normal field-of-view will be saved. 

We are also able to use the cubemap viewer and the equirectangular viewer to see how the annotations turn out and whether annotations that cross different sides are connected properly. 

  

The mask on the left (above) is an example of discontinuous objects across different faces of the cubemap. There are white borders around each face. Objects don’t connect well, and they are likely to be labeled with different classes. The mask on the right is an example of having continuous objects across different faces of the cubemap. 

 

Summary:

Our 360 annotation platform separates us from other annotation tools with our features specifically designed for 360 images, such as being able to annotate a specific side of the cubemap, our distinct drawing canvas with an expanded field-of-view, and the real-time display of annotations in equirectangular viewer. These features solve the problems of using off-the-shelf annotation platforms to annotate 360 images, such as the distortion problem and the border problem mentioned earlier in the article. We hope that the implementation of our 360 segmentation labelling platform can produce more semantic segmentation datasets for 360 images, and thus nourish the growth of research relating to computer vision task of semantic segmentation on 360 images. 

 

Reference:

  1. Armeni, Iro, et al. “Joint 2d-3d-semantic data for indoor scene understanding.” arXiv preprint arXiv:1702.01105 (2017).
  2. Gutiérrez, Jesús, et al. “Introducing UN Salient360! Benchmark: A platform for evaluating visual attention models for 360° contents.” 2018 Tenth International Conference on Quality of Multimedia Experience (QoMEX). IEEE, 2018.
  3. Zhang, Ziheng, et al. “Saliency detection in 360 videos.” Proceedings of the European Conference on Computer Vision (ECCV). 2018.
  4. Bares, W., et al. “Pano2Vid: Automatic Cinematography for Watching 360◦ Videos.”
  5. Hu, Hou-Ning, et al. “Deep 360 pilot: Learning a deep agent for piloting through 360 sports videos.” 2017 IEEE Conference on Computer Vision and Pattern Recognition (CVPR). IEEE, 2017.

Expanding Computer Vision Multi-View Stereo Capabilities: Automatic Generation of 3-dimensional Models via 360 Camera Footage

As the world we live in is three-dimension, 3D model is the most iconic representation of our world. 3D modeling allows people to see what they would not see when viewing in 2D. It gives people the ability to physically see how much real estate an object takes from all perspectives. But compared to generated from scratch, we are also able to build 3D models from video automatically.

Taiwan AI Labs has built a virtual aerial website: droneye.tw. This website has great 360 video resources. It triggers an idea. Can we use 360 videos to generate high-quality 3D model within only few flights in order to minimize the cost to obtain the 3D model? Indeed, it is feasible no matter using stereo-views computer vision algorithm or deep learning approach. The concept of 3d model reconstruction can be illustrated as figure 1 that we are able to solve 3D object coordinate from the same point on the at least 2 images.

Fig 1. Concept of 3D Reconstruction (Modified from Tokkari etc., 2017)

 

360-degree cameras capture the whole scene around a photographer in a single shot. 360 cameras are becoming a new paradigm for photogrammetry. In fact, the camera can be pointed to any direction, and the large field of view reduces the number of photographs.[1] The camera we used at the former flight is Virb 360, which record the video in panoramic ways. As a result, it cannot be used to reconstruct the 3D model directly. We have to project its equirectangular images to any FOV perspective images (Fig 2.) or cubemap so we are able to take advantage of these images to build our 3D models. It can also support reconstructing the 3D model inside the building, we can choose the image angle we want or just choose cubemap format, it will automatically use the reprojection images to generate 3D model.

Fig 2. Different angle of views from drone

 

First of all, tanksandtemples website which present a benchmark for image-based 3D reconstruction have indicated results of 3D model generated by deep learning still do not surpass the stereo-views computer vision algorithm. We have implemented both algorithms and compare the results. The test input is 16 high resolution NTU campus photos from drone. The deep learning algorithm we use is R-MVSNet, it’s an end-to-end deep learning architecture for depth map inference from multi-view images.[8] The computer vision algorithm is Structure from Motion and semi-global matching. We can tell from the result that state-of-the-art deep learning algorithm of 3D model still has a way to go. Nonetheless, deep learning algorithm for 3D reconstruction undoubtedly has a great prospect in the future.

Fig. The Architecture of R-MVSNet (Yao etc, 2019)

 

Table. Point Cloud results of deep learning and conventional computer vision

Semi-Global Matching 

R-MVSNet

   

 

Base on the above statement, we decide to apply Structure from Motion & patch matching algorithm to reconstruct our 3d model. The main steps include sparse reconstruction and dense reconstruction. In the sparse reconstruction, we use SIFT to match features. Now we have the corresponding points on each image. Then we use bundle adjustment to adjust the camera extrinsic and intrinsic by least square method.[4] After these sub-steps we obtain the more accurate camera extrinsic and intrinsic for the dense reconstruction. In the dense reconstruction, first we take advantage of camera position to calculate the depth map of each image by semi-global matching.[2] Then we fuse the neighbor depth maps to generate 3d point cloud. However, data volume of point cloud is relatively huge, we simplify the point to Delaunay triangulations or so-called mesh, which turn the points into planes.[5] Final, we texture the mesh with the corresponding images.[7] 

Fig. 3D reconstruction pipeline (Bianco etc, 2018)

 

 

Table. Result of NTU Green House

Real Picture   3D Model       
 

 

Table. Result of Tainan Qingping Park

Real 360 Picture

3D Model

   

 

Although 360 video has the advantage of multi-views in single frame, it has significant drawbacks such as unstable camera intrinsic and when projecting to the perspective images, the resolution will decrease drastically. Thus, we adopt super resolution algorithm – ESRGAN in order to overcome low-quality of images. Indeed, this strategy not only increases the details of the 3d models especially when texturing the mesh but also densify the point cloud. In order to obtain better results, we can train our own model on the “Taiwan landscape” the prevent bias of the unsuitable pre-trained model and to meet the special needs of drone data in Taiwan. 

 

Bilinear x4 SR x4      

 

Nonetheless, ESRGAN doesn’t restore the original information, it learns high frequency information in the images by inference.[9] Due to the fact, it would hurt the quality of structure from motion. If we would like to take advantage of the better results of super-resolution and also maintain the quality of Structure from Motion, we could use the SR images as input at the step of dense matching. To sum up, by using state-of-the-art deep learning algorithm such as super-resolution (ESRGAN), we may be able to reduce some drawbacks of 360 video and generate the desired 3D models.

 

Fig. Chimei Museum

 

Fig. Lin Mo-Niang Park

 

Fig. Tzu Chi Senior High School

 

Reference

  1. Barazzetti, L., Previtali, M., & Roncoroni, F. (2018). Can we use low-cost 360 degree cameras to create accurate 3D models?. International Archives of the Photogrammetry, Remote Sensing & Spatial Information Sciences, 42(2).
  2. Barnes, C., Shechtman, E., Finkelstein, A., & Goldman, D. B. (2009). PatchMatch: A randomized correspondence algorithm for structural image editing. In ACM Transactions on Graphics (ToG) (Vol. 28, No. 3, p. 24).
  3. Bianco, S., Ciocca, G., & Marelli, D. (2018). Evaluating the performance of structure from motion pipelines. Journal of Imaging, 4(8), 98.
  4. Fraundorfer, F., Scaramuzza, D., & Pollefeys, M. (2010). A constricted bundle adjustment parameterization for relative scale estimation in visual odometry. In 2010 IEEE International Conference on Robotics and Automation (pp. 1899-1904). IEEE.
  5. Jancosek, M., & Pajdla, T. (2014). Exploiting visibility information in surface reconstruction to preserve weakly supported surfaces. International scholarly research notices.
  6. Shen, S. (2013). Accurate multiple view 3d reconstruction using patch-based stereo for large-scale scenes. IEEE transactions on image processing, 22(5), 1901-1914.
  7. Waechter, M., Moehrle, N., & Goesele, M. (2014). Let there be color! Large-scale texturing of 3D reconstructions. In European Conference on Computer Vision (pp. 836-850).
  8. Wang, X., Yu, K., Wu, S., Gu, J., Liu, Y., Dong, C.,& Change Loy, C. (2018). Esrgan: Enhanced super-resolution generative adversarial networks. In Proceedings of the European Conference on Computer Vision (ECCV) (pp. 0-0).
  9. Yao, Y., Luo, Z., Li, S., Fang, T., & Quan, L. (2018). Mvsnet: Depth inference for unstructured multi-view stereo. In Proceedings of the European Conference on Computer Vision (ECCV) (pp. 767-783).

Virtual Aerial Tour

Written By: Yi-Chun Kuo, Hao-Kai Wen

Chi Po-Lin’s Beyond Beauty: Taiwan from Above brought a new perspective on our familiar island. With this spirit, we architect a smart city service, targeting to explore the surroundings of our daily life from a unique angle. To develop a prototype, we fly drones over the campus of National Taiwan University, and Anping District, Tainan City to record the street view videos with 360 camera, and build an aerial tour application. 360 camera provides flexible viewing angles for processing the videos. In this way, we only need to fly over a road once, and we can present various flying experiences. Eco-House, NTU Library, or Drunken Moon Lake may be familiar to you, but have you ever seen them from the above? Please be invited to visit the campus of NTU in the drone’s eye view

https://smartcity.ailabs.tw/aerial-tour/ntu/.

Text-to-speech attraction introduction

We integrate AI Labs’s cool factors into our service. With text-to-speech, a virtual tour guide vividly introduces the attractions to users. Videos with adjusted color, tone, brightness and contrast present a more beautiful scene to users. Drawing-style videos show a distinctive city view to visitors. Below let us introduce the methodology behind the scene.

style transferred Anping scene

 

Shaky videos is an issue for our platform. The instability of drone footage are due to the vibration of propellers. We applied Kopf’s [1] method to estimate camera poses between frames. Once we have the camera positions, we can offset the shaking and the videos are stabilized.

Color inconsistency between videos is another issue. Because the videos were taken on different days, the light and weather conditions differ a lot. Abrupt color change in the scene makes users uncomfortable. Many trials have been made to overcome this problem. Style transfer approaches fail because of non-photorealistic results. The most convincing method is [2] to our audience. Use deep features to match semantically similar regions in images, and transfer the color of corresponding regions accordingly. That is to say, the color of tree is transferred to tree and the color of the car is transferred to the car. In this way, the videos taken on different days keep consistent color.

left: original image, right: color transferred image

 

In addition to color transfer, sky replacement algorithm, such as [3], helps reduce the color inconsistency between videos. If the sky are the same between videos, human will assume the videos are shot in the same day. We developed a sky replacement algorithm to replace the cloudy sky with a clear sky. First we use semantic segmentation models to detect the coarse skyline, and use matting algorithm to refine the details. Then, the sequence of 360 camera positions is built as 360 video stabilization. We rotate the sky image with the help of these camera positions, to simulate a new sunny sky. At the end, we composite the new sky with original videos to generate appealing street view videos.

                                            up: original image, down: sky replaced image

This is the stage we are now toward building an aerial tour service. We keep exploring an interesting and innovative method to bring a unique perspective on our beautiful home.

 

Reference

[1] Kopf, Johannes. “360 video stabilization.” ACM Transactions on Graphics (TOG) 35.6 (2016): 195. [link]

[2] Liao, Jing, et al. “Visual attribute transfer through deep image analogy.” arXiv preprint arXiv:1705.01088 (2017). [link]

[3] Tsai, Yi-Hsuan, et al. “Sky is not the limit: semantic-aware sky replacement.” ACM Trans. Graph. 35.4 (2016): 149-1. [link]

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ptt.ai, open source blockchain for AI Data Justice

[ 換日線報導中文連結 ]

The beginning of Data Justice” movement

By collaborating with online citizen and social science workers in Taiwan, Taiwan AILabs promotes the Data Justice” in the following principles:

  1. Prioritize Privacy and Integrity with goodwill for applications before data collection
    • In addition to Privacy Protection Acts, review the tech giant on potential abuse of monopoly position forcing users to give up their the privacy, or misuse user content and data for different purpose. In particular, organizations that became monopoly in the market should be reviewed regularly by local administration knowing if there is any abuse of data when users are unwillingly giving up their privacy.
  2. Users’ data and activities belong to users
    • The platform should remain neutral to avoid the misuse of user data and its creation.
  3. Public data collected should open for public researches
    • The government organization data holder is responsible for its openness while privacy and integrity are secured.For example, health insurance data for public health and smart city data for traffic researches.
  4. Regulate mandatory data openness
    • For the data critical to major public welfare controlled by monopoly private agency, we shall equip the administration the power for data openness.
    • For example, Taipower electric power usage data in Taiwan.

Monopoly now is worse than oil monopoly”

In 1882, the American oil giant John D. Rockefeller founded Standard Oil Trust and united with 40 oil-related companies to reach price control. In 1890, U.S. government sued Standard Oil Trust to prevent unfair monopoly. The antitrust laws have been formulated so as to ensure fair trade, fair competition, and prevent price manipulation. The governments of various countries followed the movement to establish anti-monopoly laws. In 1984 AT&T, a telecom giant, was split into several companies for antitrust laws. Microsoft was sued in 2001 for having Internet Explorer in its operating systems.

In 2003, Network Neutrality principle mandated ISPs (Internet Service Providers) to treat all data on Internet the same. FCC (Federal Communications Commission) successfully stopped Comcast, AT&T, Verizon and other giants from slowing down or throttling traffic based on application or domain level. Apple FaceTime, Google YouTube and Netflix are benefited from the principle. After 10 years, the oil and ISPs companies are no longer in the top 10 most valuable companies in the world. Instead, the Internet companies protected by Network Neutrality a decade ago have became the new giants. In the US market, the most valuable companies in the world dominate the market shares in many places. In February 2018, Apple reached 50% of the smart phone market share, Google dominated more than 60% of search traffic, and Facebook controlled nearly 70% of social traffic. Facebook and Google two companies have controlled 73% of the online Ads market. Amazon is on the path grabbing 50% of online shopping revenue. At China side, the situation is even worse. AliPay is owned by Alibaba and WePay is owned by WeChat. Two companies together contributed to 90% of China’s payment market.

When data became weapons, innovations and users become meatloaf

After series of AI breakthrough in the 2010’s, big data as import as crude oil. In internet era, users grant Internet companies permission on collecting their personal data for connecting with creditable users and content out of convenience. For example, the magazine publishes articles on Facebook because Facebook allows users to subscribe their article. At the same time, the publisher can manage their subscribers’ relationship with messenger system. The recommendation system helped to rank users and their content published. All the free services are sponsored from advertisements, which pay the cost of internet space and traffic. This model has encouraged more users to join the platform. Users and content accumulated on the platform also attracted more users to participate in. After 4G mobile era, mobile users are always online. It pushed the data aggregation to a whole new level. After merging and acquisition between Internet companies, a few companies stands out dominating user’s daily data today. New initiatives can no longer reach users easily by launching a new website or an app. On the other hand, Internet giants can easily issue a copycat of innovation, and leverage their traffic, funding and data resources to gain the territories. Startups had little choice but being acquired or burnout by unfair competition. Fewer and fewer stories about innovation from garages. More and more stories about tech giants’ copy startup ideas before they being shaped. There is a well quoted statement in China for example: Being acquired or die, new start-up now will never bypass the giants today.”. The phenomenon of monopoly also limited users’ choices. If a user does not consent to the data collection policy there is no alternative platform usually.

Net Neutrality repealed, giants eat the world

Nasim Aghdam’s anger at YouTube casts a nightmarish shadow over how it deals with creators and advertisers. She shot at the YouTube headquarters and caused 3 injuries. She killed herself in the end. At the beginning of Internet era, innovative content creators can be reasonably rewarded for their own creations. However, after the platform became monopoly, content providers find that their creation of content are ranked through opaque algorithms which ranked their content farther and farther away from their loyal subscribers. Before their subscribers can reach their content, poor advertising and fake news stand on the way. If the publisher wants to retain the original popularity, the content creator need also pay for advertisement. Suddenly reputable content providers are being charged for reaching their own loyal subscribers. Even worse, their subscribers’ information and user behavior are being consumed platform’s machine learning algorithms for serving targeting Ads. At the same time, the platform doesn’t really effectively screen the Advertisers, low quality fake news and fake ads are being served. It is known for scams and elections. After Facebook scandal, users discovered their own private data are being used through analysis tools to attack their mind. However at the #deletefacebook movement, users find no alternative platform due to the monopoly of technical giants. Friends and users are at the platform.

In December 2017, FCC voted to repeal the Net Neutrality principle for the reason that US had failed to achieved Net Neutrality. ISPs companies are not the ones to blame. After a decade, Internet companies who benefited from Net Neutrality are now the monopoly giants and Net Neutrality wasn’t able to be applied for their private ranking and censorship algorithm. Facebook for example offers mobile access to selected sites on its platform at different charge of data service which was widely panned for violating net neutrality principles. It is still active in 63 other countries around the world. The situation is getting worse in the era of AI. Tech giants have leveraged their data power and stepped into the automotive, medical, home, manufacturing, retail, and financial sectors. Through acquisitions by the giants rapidly accumulating new types of vertical data and forcing the traditional industries opening up their data ownership. The traditional industries are facing a even larger and smarter technology monopoly than the ISP or oil companies in a decades.

Taiwan experience may mitigate global data monopoly

Starting from the root cause, at the vertical point of view, The user who contributed the data” was motivated by the trust” of the their friends or the reputable content provider. In order to have the convenience and better service, the user consents to collecting their private data and grant the platform for further analysis. The user who contributed the content” consents to publishing their creation on the platform because the users are already on the platform. The platform now owns the power of the data and content that should originally belong to the users and publisher. For privacy, safety and convenience purpose, the platform prevents other platforms or users from consuming the data. Repeatedly, it results in an exclusive platform for users and content providers.

From horizontal point of view, in order to reach user, for data and traffic, the startup company signed unfair consent with the platform. In the end, the good innovations is usually swallowed by the platform because the platform also owns data and traffic for the innovations. Therefore, the platform will become larger and larger by either merging or copying the good innovation.

In order to break this vicious cycle and create fair competition environment for AI researches. Taiwan AILabs shared at 2018 3/27 Taipei Global Smart City Expo and a panel at 3/28 Taiwan German 2018 Global Solution Workshop with visiting experts and scholars on data policies making. Taiwan AILabs exchanged Taiwan’s unique experience on Data Justice. In the discussion we concluded opportunities that can potentially break the cycle.

The opportunities comes from the the following observations in Taiwan. Currently, the mainstream of the world’s online social network platforms is provided by private companies optimized for advertising revenue. Taiwan has a mature network of users, open source workers and open data campaigns. Internet users” in Taiwan are closer to online citizens”. Taiwan Internet platform, PTT(ptt.cc) for example, is not running for profit. The users elect the managers directly. Over the years, this culture has not cooled down. PTT is still dominating. Due to its equity of voice, it is difficult to be manipulated by Ads contribution. Fake news and fraud can be easily detected by its online evidence. PTT is a more of a major platform for public opinions compared with Facebook in Taiwan. With the collaboration between PTT and Taiwan AILabs, it now has its AI news writer to report news out of its users’ activities. The AI based new writer can minimize editor’s bias.

g0v.tw is another group of non profit organization in Taiwan focusing on citizen science and technology. It promotes the transparency and openness of government organizations through hackathon. It collaborated with the government, academia, non-governmental organizations, and international organizations for data openness on public data with open source collaboration in various fields.

Introducing ptt.ai project: using blockchain for Data Justice” in AI era

PTT is Taiwan’s most impactful online platform running for 23 years. It has its own digital currency – P coin, instant messaging, e-mail, users, elections and administrators elected by users. However, the services hosting the online platform are still relatively centralized. 

In the past, users chose a trusted platform for trusted information. For convenience and Internet space, users and content providers consent to unfair data collection. To avoid centralized data storage, blockchain technology gives new directions. Blockchain is capable to certify the users and content by its chain of trust. The credit system is not built on top of single owner and at the same time the content storage system is also built on top of the chain. It avoids the control of a single organization which becomes the super power.

Ptt.ai is a research starting to learn from PTT’s data economy, combining with the latest blockchain encryption technology and implementing in the decentralization approach.

The mainstream social network platforms in China and the United States created new super power of data through the creation of users and users’ own friends. It will continue to collect more information by horizontally merging industries with unequal data power. The launch of ptt.ai is a thinking of data ownership in different direction. We hope to study how to upgrade the system PTT in the era of AI, and use this platform as the basis for enabling more industries to cooperate with data platforms. It gives the data control back to users and mitigate the data monopoly happening. Ptt.ai will also collaborate with leading players on the automotive, medical, smart home, manufacturing, retail, and financial sectors who are interested in creating open community platform. 

Currently, the experimentation of technology started on an independent platform. It does not involve the operation or migration of the current PTT yet. Please follow the latest news of ptt.ai on http://ptt.ai .

 

[2018/10/24 Updates]:

The open source project is on github now: https://github.com/ailabstw/go-pttai

[2019/4/2 Updates]:

More open source projects are on github now:

 

AILabs builds intelligence behind Taipei Traffic Density Network

Taipei is a city with millions of cars and motorcycles. Heavy traffic congestion occurs on the streets daily. Incidents have serious impact to traffic. Taipei have built tens of thousands citywide cameras recording real-time traffic videos. Police officers will consume the result to remove the traffic congestion. However, existing method requires human effort, only 16% of the incidents are manually detected.

Unlike cities in Mainland China, 2 major constraints exist on building the smart city systems in Taiwan. Humanity with Privacy and Integrity is the top priority. Taiwan is highly sensitive on human rights. The policy making need  to ensure the goodwill with integrity. The protection of privacy and prevention of the future abuse and misuse together are the top priority on building the system. Taipei used videos with lower resolution that can’t further recognize residents’ identity in the video. Second, the solution need to be green and environmentally friendly. Forcing the city government to retire the old cameras is challenging. At the same time, Taipei city used low-frame-rate cameras to reduce the energy consumption. With these 2 constraints, Taiwan AILabs collaborated with Taipei City Government to build the autonomous traffic detection and prediction system.

Existing Traffic Cameras (CCTV) of Taipei City

The videos taken by the existing traffic cameras are low-resolution and low-frame-rate. We design a method with robust network to detect and predict the traffic congestion in real-time. We presented Taipei Traffic Density Network (TTDN). The network is able to precisely detect vehicle density of defined region in real-time. TTDN is a fully convolutional networks. In TTDN, we acquire multi-scale features from the images of traffic videos and obtain the estimation of vehicle density after pixel-wise regressions.

 

The Outline of Taipei Traffic Density Network (TTDN)

We would like to remark that our approach is intertwined with our key ingredients of smart city, protection of privacy and conservation of energy. Since the traffic videos are low-resolution, it’s hard to perform any face recognition or plate recognition. This ensure the protection of privacy. Meanwhile, on top of reusing existing traffic cameras, the data with low-resolution and low-frame-rate also reduce storage space and the computational cost.

Using the mathematical assumption of vehicle density map, we can efficiently detect and predict traffic congestion. Besides using density map directly, some existing works show that the density map is also a strong feature map. The fusion of density map and some other features may be able to detect accident, road construction, etc. This is an interesting topic we are currently working on.


The 2018 Smart City Summit & Expo (SCSE)

Feautured Photo by  highwaysagency / CC BY 2.0