What I want to do
My attempt and results
Thanks to numerous examples available on the internet I've been able to implement simple WebGL application that achieves satisfactory performance results even on mobile phones. Application got merged to the main git repository and is available in beta version on infragram.org.
How it works
Application draws a rectangle consisting of two triangles on HTML5 canvas element using WebGL calls. The rectangle is textured using an infrablue image provided by user. Graphics card renders NDVI map using fragment shader written specially for that task. The NDVI-calculating fragment shader executes concurrently on multiple pixels at once, effectively providing a massive speed-up in processing time.