luminance

image
image win
image dim

luminance image

luminance image(id)

        Returns the luminance of the pixels of image id.
Options:
average: Returns the average luminance of image id.
win(x1,y1,x2,y2): pixels of window (x1,y1,x2,y2).

luminance image(id)=v1,v2,...

        Changes the color of the imageid so that the luminance of pixel i is vi.

luminance luminance image(id)=v

        Changes the color of the imageid so that luminance(pixel)*=c.
Options:
limit: avoid color overflow.

luminance image win

luminance image(id)win(x1,y1,x2,y2)

        Returns the luminance of the pixels of window (x1,y1,x2,y2) of image id.

luminance image(id)win(n1,n2)

        Returns the average luminances of n1*n2 sub windows of image id.

luminance image dim

luminance image(id)dim(nx,ny)

Returns (x,y,lum) with (x,y) = normalized coordinates of the sub window of maximum luminance lum.
Options:
average: average luminance.
min: minimum luminance.