# MATLAB Programming/Psychtoolbox/Screen Commands/GetImage

Usage:

imageArray=Screen(windowPtr,'GetImage',[rect])

Slowly copy an image from a window, returning a MATLAB uint8 array. If the window's *pixelSize*>8 then the returned *imageArray* has three layers, an RGB image. *rect* is in window coordinates, and its default is the whole window.

As of April, 1998, *imageArray* is now uint8 instead of double to save space (a factor of 8). However, MATLAB will issue an error if you try to do math on a uint8 array, so you may need to use DOUBLE to convert it, e.g. imageArray/255 will produce an error, but double(imageArray)/255 is ok. Also see
PutImage and CopyWindow.