Confessions of a researchaholic

October 26, 2015

Autocomplete hand-drawn animations

Filed under: Real — liyiwei @ 9:00 pm
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[This post is for answering press inquiries about our SIGGRAPH Asia 2015 paper titled “autocomplete hand-drawn animations”.]

On August 2014, Koji Yatani (at the University of Tokyo) asked me (on Facebook!) to recommend students for a MSR Asia internship under Takaaki Shiratori with topics in animation and sketch UI. I recommended my HKU PhD student Jun Xing, who just got a paper in SIGGRAPH Asia 2014 titled “autocomplete painting repetitions”.
(Both Koji and I were with MSR. That is how we got to know each other even though we have no overlap.)

Our initial goal was to help users create animated emoji in instant messaging. I wanted to make sure the project is significant enough (e.g. for SIGGRAPH) while leveraging our collective expertise as much as possible. Thus, I proposed to extend the aforementioned SIGGRAPH Asia 2014 paper, which can autocomplete only single-frame drawings, for multi-frame animations. The main goal for both projects is to help ordinary users draw as easily and effectively as possible.
(My dad is an artist, but I have yet to learn how to draw. So as any decent computer scientist would do, I ask algorithms for help.)

Jun designed most of the user interface and algorithms, and implemented the entire system. He is definitely one of the best students I have worked with.

We plan to ship prototypes of the system to gather user opinions for further research and improvements, starting with mobile apps followed by desktop versions.

Contrary to what some press reported, this is NOT a Microsoft technology or product (at least not at this moment of writing). None of the authors were with Microsoft during the key stages of the project development. In particular, the core ideas were conceived before the start of the internship, and Jun had to come back to HKU to finish the project after Takaaki left Microsoft about 1 month before the paper deadline.

August 5, 2015

Good collaborator

Filed under: Real — liyiwei @ 11:42 am

People who are the most important in my life are those who make me better.

I would like to thank Chia-Kai Liang, my collaborator in a light field camera design project.

  • The best kind of research projects has both academic and industry values. He brought me into this very interesting problem, for which our solution turns into a SIGGRAPH paper and part of a next generation Lytro camera.

  • Initially I thought the project is too engineering-oriented for a good research paper. He corrected my blind spot and kept us moving on.
    (I am still learning to walk the very thin line between optimism and pessimism for research.)

  • The project involved heavy workloads in data capture and prototype engineering. He participated and coordinated all these with the product teams and paper co-authors.

  • He wrote the code and paper with me, more closely and more effectively than my previous (excellent) collaborators.

  • I learned several technicalities thanks to him, such as designing light field cameras, using cmake without blowing off our legs, putting python (programming language) to good use, automating speech synthesis for video dubbing, etc.

  • He made sure I started preparing our SIGGRAPH talk before inside the convention center.

I look forward to further collaboration with Chia-Kai in innovating computational photography.

May 31, 2015

Should we submit?

Filed under: Real — liyiwei @ 1:33 pm
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The deadline is approaching and we have this paper that might or might not be ready. Should we submit?

A lot can be learned only by going through actually paper review cycles. So it pays off to do our best to meet the deadline.

On the other hand, a bad submission might get its potentially good ideas scooped by the reviewers without receiving much useful feedback.

Thus, I recommend submitting only those with a reasonable chance of getting accepted but let the first author make the final call as the tie breaker.

March 16, 2015

PhD student recruiting

Filed under: Real — liyiwei @ 2:15 pm
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On behalf of the HKU CS department, I would like to invite top students all over the world to apply our PhD program for academic year 2016-17.

HKU is a top ranked university conducting world class research and teaching. It is located at the heart of Hong Kong Island, aka the downtown area.
Hong Kong’s diverse culture, liberal policy, and vibrant economy offer unique life styles and career opportunities.

February 21, 2015

It is still possible to publish texture synthesis paper!

Filed under: Real — liyiwei @ 11:54 am

Self Tuning Texture Optimization

December 20, 2014

Minimal quality bar to become my internal student

Filed under: Real — liyiwei @ 7:08 pm
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You should be able to understand and implement an existing research paper (e.g. SIGGRAPH) or software system (e.g. a renderer/simulator) as well as reproduce the corresponding results.

Otherwise, you are not ready for a research or even a development position.

As a reference point, my current HKU PhD student, Jun Xing, once managed to reproduce 3 SIGGRAPH papers in a span of about 5 days.

December 11, 2014

Street credit

Filed under: Real — liyiwei @ 6:55 pm
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Coauthors revealed a secret in a recent paper that gave us all street credits.
(It is in plain sight for anyone to see, so I won’t tell.)

November 9, 2014

Manage presentation via slides

Filed under: Real — liyiwei @ 12:36 am
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If I need to produce a video or give a talk for a research project, here is my current workflow.

Write down the story/script in plain text and rough drawings. Do not use any specific media at this early stage as it can prematurely limit our creativity.

Commit the script into a storyboard via slides (e.g. PowerPoint).
I then gradually flesh out the storyboard into a video and talk using the same set of slide files. This might sound unusual, so let me explain.

Start with video. When I was in grad school I learned time-line based tools (e.g. Adobe Premiere) to author and edit videos. But recently I found it more natural to use slides instead of time-lines for research videos. The main reason is that a research video usually contains short video segments glued together by narration, which involves more storyboarding than time-line manipulation.

I first produce the individual video segments using specific tools (e.g. dumping individual frames from my renderer and convert them into a video via MovieMaker), and embed them into PowerPoint slides. PowerPoint provides a rich set of tools for annotation, animation, and transition, which I find handy (and harder to do via Adobe Premiere). I automate all object animations and slide transitions, and dump the entire project into a video file.
I submit the video along with the paper, and go screw around.

PowerPoint allows flexible manual control, but it can be tedious due to lack of automation/scripting tools. Thus, it is important to properly decompose the above process into (1) automatic creation of (video) components and (2) manual insertion/combination of these components into the slides. It is a trade-off among quality, control, and manual labor.

When the time comes to prepare the talk, I can simply start with my slide file, which already contains the script, the video segments, and associated effects. I just need to turn off those automatic animations and transitions that I wish to manual control, and add additional information for a talk, usually verbal stuff such as previous works, algorithm details, and future directions.

I find this much more efficient than starting new slides from scratch.
I also find that for those projects that I were too lazy/busy to make videos, the talk slides I ended up doing are often not too far from being videos.
It is almost always a good idea to have a video to present the gist of our project in 5 minutes, more appealing and efficient than absorbing the same amount of information from reading the paper.

If you find yourself worrying about typography, it is a sign of too much text in the slides. Use intuitive pictures, illustrations, and animations, instead of texts and (worse) equations.

As an example, here is an early version of the video-slide file for my siga14 paper autocomplete painting repetitions.

July 29, 2014

Teaching assistant

Filed under: Real — liyiwei @ 10:40 am
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TA is a great training for presentation, communication, management, and personal skills. You have to be able to describe course materials in a way that the students can understand, and you have to balance their learning and happiness. Naturally, students want to minimize workloads while maximizing grades. Dealing with a large class (hundreds of undergrad students) is not unlike managing a mob.

It is great if one can focus exclusively on research. That is what I prefer then as a grad student and now as a prof. But without sufficient communication and personal skills, one cannot succeed even with great research skills.
To start with, a great idea is of no value if it cannot be understood and appreciated by people.

Thus, I do not consider TA a waste of time. Quite on the contrary, it is an indispensable part of research training.

July 25, 2014

Stephen King on how to write

Filed under: Real — liyiwei @ 11:00 am
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It is striking how much the advice on fiction writing applies to technical writing and conducting research in general, despite some important differences, e.g. scientific writings should be precise instead of leaving rooms for imagination.

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