>Psychtoolbox>PsychGLImageProcessing

Build a mip-map image resolution pyramid for given texture.

CreateResolutionPyramid(tex [, glsl=0][, usebilinear=0])

‘tex’ must be the Screen() texture or offscreen window handle of a
texture or offscreen window of type GL_TEXTURE_2D, ie., created with
‘specialFlags’ setting 1. The function will create a OpenGL mip-map
resolution pyramid by successive downsampling of ‘tex’ image content down
to a image of 1x1 pixels. If ‘glsl’ is provided as handle to a shader, it
will use that shader to do the downsampling, otherwise it will use
bilinear filtering for successive pyramid levels. If ‘usebilinear’ is set
to 1 it will feed the shader with linear interpolated samples, otherwise
with nearest neighbour samples.

You will likely also want to set ‘specialFlags’ flag 8 or 16 to prevent
Screen(‘DrawTexture’) from overwriting the image pyramid with its own
auto-generated one.

This needs a modern GLSL shading capable graphics card to work.