Chrisir: thanks for your response. I'm looking for something beyond what I can find in the references. Looking in the Javadoc for PImage I found the sentence above referring to some code supplied by Toxi. I think if I could see this code I could figure out what I'm trying to figure out. Toxi has a lot of stuff on his website but I can't find the code that the sentence refers to.
The underlying problem I'm trying to solve is taking an image, magnifying it, then identifying colors on the magnified image from the mouse location. What I've figured out is that there is a simple 1 to 1 correspondence of x-y position as per the mouse location only on an unmodified image, that is, one whose width and height as displayed are the same as for the original image. The pixel array represents the original image, not the displayed image. I'd like to understand how to identify the pixel information corresponding to the mouse position on the displayed image when the displayed image doesn't have the same size height and width as the original image. When processing displays an image different from its original, it must play some tricks in terms of adding or subtracting pixels for the displayed image. If there's no way to directly access the pixels of the displayed image, then I could figure out what they are if I knew the tricks.
