Outputs the modified data as a grid. This object is useful for color correction. for each pixel it takes it apart, looks up each part separately in the colormap and constructs a new pixel from that. vary this: currently works only with 3 channels at a time! it also works on non-images, for example on colormaps themselves, but the last dimension must be channels, and there must be three channels. Note: if you just need to apply a palette on an indexed-color picture or greyscale picture, you don't need this. Just use #store instead. grid that will be modified by the colormap Colormap (aka palette) is a grid[intensity, channels]