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Talk: Computer Graphics, Part 1

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As promised earlier, i gave a talk at entropia in december. I tried to touch many of the non-hardware-oriented topics in computer graphics, with a focus on those that are interesting (to me, at least) and easy to explain without too much background knowledge in math or computer science.

The talk was an experiment for me in several ways. First, the presentation style: The slides should contain as little text as possible, providing only visual assistance to what i said rather than guiding the talk themselves. In typical university or conference talks, i usually read the whole content-stuffed slide as soon as it appears without listening to what the lecturer says. The remaining two thirds of the time the slide takes usually consists of waiting for the next slide while trying not to fall asleep. I did not want to go as far into the opossite direction as Lawrence Lessig does because, obviously, the talk would be graphics-oriented and some of the pictures would need time to sink in and be explained. I think the style worked out fine and i surprised myself by talking quite a lot about slides with just one picture on them although i had not been practicing.

Second, the technical means: It was also the first time for me to use the Latex Beamer Class for slides. Creating the slides was painless enough with the help of my latex preprocessor, but the result did not convince me: (La)tex is not made for displaying pixel data on screen, causing images to be resized that want to displayed exactly 1:1. Most pdf viewers use Nearest Neighbour interpolation for resizing pictures, making all my nice pictures look bad - which is somewhat embarrassing for a talk that covers image filtering and interpolation. With evince i found a pdf viewer that performs other interpolation methods, making the result bearable. Nevertheless i will have to find some other way to show images next time. Possibly i will create the slides as images themselves and present them with some image viewer like gqview. And maybe i’ll end up writing another minimalist slide-defining markup language that creates png images.

Third, i wanted to be able to publish the slides. This meant restricting myself to pictures released under some reasonably free licence or making my own. I ended up using many pictures from the Wikimedia Commons, usually modifying them to fit the black background. I also made many of the pictures myself. I included a file that provides proper attribution to the creators of the CC-Attribution-images in the archive containing the slides. This involved finding the authors of each of the images which was quite painful (and the reason for the long time it took to publish the slides). I’d really appreciate a Creative Commons license or something similar that does not force users of my work to remember or research my name - releasing into the Public Domain is not possible in Germany. Just granting all users every imaginable rights to to as they wish (which i hereby do) leaves me doubting the lawfulness of this statement. I’d really like some standard way of doing this.

All in all things went well and i certainly learned something in the two months it took to prepare a talk that was over in about 90 minutes. As i invested this considerable amount of time into something that did not last that long, i will certainly consider giving it again (or recycling the slides for a similar talk).

The talk’s article in the amazing entropia wiki contains a link to the slides, some of whom may not make that much sense without any comment.

And here’s the flash version:

LaTeX beamer markup = less suckage

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There are many bad things about latex - like not being able to use footnotes in tables, color verbatim text for syntax highlighting or center math expressions. One general problem is its verbosity when only a small subset of its functionality is needed. Especially when using the beamer class, the mental and textual overhead made writing latex too bothersome for me to be fun. A simple wiki-style markup would suffice for most tasks when creating slides, with extra functionality only needed for special slides like titles. Wouldn't it be nice to write

=Why tex needs to be replaced=
There are countless reasons:
* it's old
* I don't like it

which would become

\frametitle{Why tex needs to be replaced}
There are countless reasons:
\item it's old
\item I don't like it

I made a primitive LaTeX preprocessor in lisp that does just that. It handles slides, converts itemizations and includes and resizes graphics, while retaining all the nice features that make us use latex in the first place (i.e. the math mode). Things to improve include support for enumerations and flushright/centering and a more friendly shellscript. I will probably update it as I progress with the talk i'm currently preparing which will now be all the more awesome.

You can check out everything from svn:// or download it directly. With sbcl installed, just run to create an example pdf.