Very often in image editing programs one needs to composite an image (with or without an alpha channel) over a checkerboard pattern, to indicate the transparency of the image. This method makes it fairly easy to scale the image and composite it in such way: ]]> The first 3 parameters are the same ones as for scale_simple(). The rest are as follows: an integer in the 0..255 range specifying the overall level of transparency for the image. the size of the checks in the checkerboard pattern (has to be a power of 2). the colors of the checks ('pixel' property of GdkColor)