Lucas wrote: > I want to change some pixel value in the picture file. how to do it? > The most popular way is probably the Python Image Library, known to its friends as PIL:
http://www.pythonware.com/products/pil/ You will see from http://www.pythonware.com/library/pil/handbook/image.htm that images have .getpixel() and .putpixel() methods that will allow you to read and set individual pixels if you want. Be aware that the forthcoming release will give faster access using something called "pixel access objects", about which I know nothing. > If I read the file in binary mode, a bit == a pixel ? > Only for monochrome images, of course. Greyscale and color images have more bits per pixel, and some formats use a palette mapping to allow high color-fidelity with fewer bits per pixel (GIF is one such format). Download PIL and play with it. I'm sure you'll have a lot of fun, and you can do a surprising amount of processing just noodling around in an interactive interpreter session. regards Steve -- Steve Holden +44 150 684 7255 +1 800 494 3119 Holden Web LLC/Ltd http://www.holdenweb.com Skype: holdenweb http://holdenweb.blogspot.com Recent Ramblings http://del.icio.us/steve.holden -- http://mail.python.org/mailman/listinfo/python-list
