Hi Stefan, Stefan Behnel wrote: > News123, 03.03.2010 01:38: >> I created a grayscale image with PIL. >> >> Now I would like to write a C function, which reads a;most all pixels >> and will modify a few of them. >> >> My current approach is: >> - transform the image to a string() >> - create a byte array huge enough to contain the resulting image >> - call my c_function, which copies over the entire image in order >> to modify a few pixels >> How can I achieve this with the least amount of copies? > > Take a look at Cython instead, it will allow you to access PIL's image > buffer directly, instead of copying the data. It will also simplify and > speed up your C wrapper code. > > Stefan >
I don't know Cython. Having looked at the web site I'm not entirely sure, I understood your suggestion. Do you mean - to stay with Python 2.6 and to implement only my extension in Cython. This might be very attractive. If yes, can you recommend some url's / tutorials / etc. which might help to implement a cython extension for python2.6. which reads and modifies a pixel of a PIL image. or do you mean - to switch entirely from Python 2.6 to Cython. I would be reluctant to do so, as I have already a lot of existing code. and I do not have the time to check the entire code base for portability issues thanks in advance N -- http://mail.python.org/mailman/listinfo/python-list
