On 9 13 , 4 43 , Laurent Pointal <[EMAIL PROTECTED]> wrote: > Pacino a écrit : > > > Hi, everyone, > > > I am wondering whether it's possible to read part (e.g. 1000*1000) of > > a huge jpeg file (e.g. 30000*30000) and save it to another jpeg file > > by pure python. I failed to read the whole file and split it, because > > it would cost 2GB memory. > > > Can anyone help me? Any comments would be appreciated. > > > Thanks. > > > Robert > > Just reading parts of the *file* is easy (see tell() seek() and read() > methods on files). > But to extract a part of the *picture*, you must uncompress the picture > in memory, grab the sub-picture, and save it back - generally with > compression. I can't see how you can bypass the uncompress/compress > phases and the corresponding memory use. > > A+ > > Laurent.
The most difficult part is the uncompress part. I don't want the whole picture to be uncompressed in the memory, because it will consume a lot of memory (2GB, as I mentioned). My goal is to uncompress part of the picture into the memory. I just read some article on this subject (http://mail.python.org/ pipermail/image-sig/1999-April/000713.html) , but haven't test it out yet. Robert
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