Thread: comparing bitmaps

Hi All,

Can anybody sugest me a way to compare two bitmaps
and create a third bitmap showing the difference of the two.
Alternatively, can anyone point me to a tool that would do
this for me ?

Thanks,

bigSteve

what exactly is "the difference" When a pixel is a different color you output what? That's a strange application and I wonder what you want it for. What purpose will it serve? If you just want to know which pixels are not the same, Salem's little nexted loop is all you need to do. Then I suppose black could mean same and white could mean different. Useless though.

Could images be of different size?

Originally posted by FillYourBrain
Useless though.

Not quite. This method is often used in motion detectors, comparing two frames and registering changes (Changes in the pixels = movement).
I guess there is some similar function in optical mice/stuff too.