[comp.sys.mac.hypercard] Pixel counting in HyperCard

peter@gbg.infolog.se (Peter ) (02/01/91)

My problem is that I want to compare two bit-mapped images in HyperCard 
(or SuperCard). I want to find out the number of bits that differ between 
the two pictures. 

Does anyone know a simple method for this or do I have to manipulate the 
underlying representation. In the later case how can that be done. 

One step in the right direction might be to 'paste' one image on top of 
the other with 'xor' and then count the resulting bits. But then how can 
this pixel counting be done in HyperCard.


Thanks,

-Peter

peter@gbg.infolog.se