Hi, AFIK there is no other way to distinguish pixels becuase an image is a record of intensity values. But you can use the derivatives of the intensity value like brightness, contrast, color, gamma etc... Regarding your first question...I second chris...because its a huge task to convert any image into a matrix form. Better you opt any tools or libraries. Or else do it for the widely used image formats instead of all. Bye, Cool Ju :cool: Dream Ur Destiny