Hello World at 24.6hz

I've written the first mockup version of the picture to sound conversion software in python. Since my lasers still haven't come (GRRR!) I've written a simulated wall to project my sound driven beam onto. I'm surprised how crisp the image looks (speakers may blur it or make it worse... don't know yet, but I think I can compensate for that regardless) at reasonable refresh rates and resolutions. I've projected "hello, world" at 256*30 with a 3 pixel horizontal granularity, getting 24.6hz refresh rate. Here is the original image:



and here is the final image:



I've written a library that takes an image as input and spits out a sound file as output. The software graphs laser position vs time, by associating a scan speed (and hence positions) with each pixel's brightness. When all the pixels have been converted to positions, the software converts the graph from a position reference to a time reference. This is done at a customisable granularity, so clarity and contrast in the image can be swapped for scan speed to keep refresh rates up. This should have some interesting effects when applied to full-screen conversions, and allows for other optimizations like dynamic detail changing to achieve best accuracy at a given framerate.

I can't wait for my lasers to arrive so I can test this out practically, but given the small movement of speakers I think I'm going to arrange a lense system to magnify its effect. The system should still have infinite focus though, even with lenses in it. Among my other ideas for these software controlled scanners are software/intelligent keystoning and deformation mapping to allow good projections on bumpy surfaces.