How Socialcam designs new video filters

Several months ago, we added live video filters to Socialcam. Per pixel modification and capture of video in real time is hard, and takes a lot of optimization to work well on older devices pre iOS 5. The real challenge, however, was designing cool filters. My first attempt just swizzled bits in video data: interesting, but ugly. Next, I added code to apply a matrix transformation to the color-space, and came up with scripts to build contrast, brightness and hue-rotation matrices. This worked, and we shipped the first version with transforms generated with these tools. But the process was slow, required a lot of iteration, and the filters it produced just lacked pizzazz. So, for our final version, I embedded an RGB gradient image in the corner of a video clip, and wrote a script to extract a color transformation from this reference image. Now, we can give this clip to any designer or videographer, and they can have at it with whatever tools they like. They give the processed clip back to me, I extract a color transform from it, and bam, a new filter!

If you are passionate about mobile, video, or hard problems, drop us a line: founders@socialcam.com. We are a team of 3 co-founders in SF looking to hire.