I'm using Opengles on ubuntu on embedded platform. I'm trying to do some computer vision on a large texture 1024*1024. I have done some shaders on a larage texture that is coming from a camera, then I wanted to read back the pixels to do some manuiplations.
Using glreadpixels is slow to read the texture that is generated by the shader, so I proposed to copy the whole large texture from the camera to a small quad using an FBO, then use glreadpixesl to read the pixels from that quad, then do the processing on that quad. If I want to show the result, convert again that FBO to a large one.
Basically the idea is to reduce the 1k*1k texture to small quad, do the processing, then render it back to 1k*1k.
Would that solution work ?