[reportlab-users] Image compression

[Robin Becker]

Farid Adigamov wrote:

> Hello!

> 

> Is there any trick to switch off image compression?

> Thanks.

> 

.......

We have an environment variable called RL_pageCompression that turns on and off 
the stream compression, but I think the image compression is done 
unconditionally except for natively handled jpegs. I can probably add an extra 
flag if you really want. If you're just experimenting then this method in 
pdfdoc.py should be modified

     def loadImageFromSRC(self, im):
         "Extracts the stream, width and height"
         fp = im.jpeg_fh()
         if fp:
             self.loadImageFromJPEG(fp)
         else:
             zlib = import_zlib()
             if not zlib: return
             self.width, self.height = im.getSize()
             raw = im.getRGBData()
             assert(len(raw) == self.width*self.height, "Wrong amount of data 
for image")
-           self.streamContent = pdfutils._AsciiBase85Encode(zlib.compress(raw))
+           self.streamContent = pdfutils._AsciiBase85Encode(raw) 



             self.colorSpace= _mode2CS[im.mode]
             self.bitsPerComponent = 8
-           self._filters = 'ASCII85Decode','FlateDecode' #'A85','Fl'
+           self._filters = 'ASCII85Decode',
             self._checkTransparency(im)




that will stop the compression for most images, but the image data is still 
ascii 85 encoded. If you don't even want A85 then I think you're liable to get 
problems, but the change should be obvious.
-- 
Robin Becker