Tino Wildenhain wrote:
Nicolas Georgakopoulos schrieb:
Hello Zopistas,
I need a little guidance for a site that must make image processing on the fly. Users should be able to upload image files and after some pixels manipulation they should see the image preview after the changes and download it.
You should be much more precise about what "some pixels manipulation" actually means :-) Writing a drawing program is not so easy I think. Maybe with more client side intelligence...
It will not be some kind of drawing program , just some simple changes in the pixels values.
I have installed PIL successfully for that reason (thanks to smiley Chris) so I can use it as an external method.
For more then just a single convert (even then) I'd write a complete external product. Its much easier to test and install and can do more.
I don't have any experience writing external products... should be easy if I finish the python programming part as a simple traditional python release and then to implement it as a Zope product ?
I have thought to do this implementation uploading the file to the ZopeDB and change it there or should the file be uploaded in the local file system ?
Actually depends on what you want to do and what you want to do after the changes. E.g. do you want to save a complete history of the manipulation? Then I'd go ZODB completely. If you dont want to save the image, I'd go tempfiles and pass the handles to them around the SESSION. (see tempfile module)
Maybe a combination is apropriate.
Saving the history of the image process actions it is not required. Saving the images ... maybe. I will check this tempfile module.
either way , what should I know so I can do that ?
You should experiment with PIL - maybe outside zope.
Im am already experimenting with PIL in a python shell and learning PIL it is not my purpose of this mail ;-)
You should learn how to write a simple python based product. Will check the Zope book for that.. You should read about ZODB programming so not to read whole image objects at once.
For what part of my needs should I read about ZODB ? Can't understand the "not to read whole image objects at once" cheers..