[reportlab-users] Writing smaller image-only PDFs

Nicholas Watmough nickw at deakin.edu.au
Fri Feb 10 08:41:48 EST 2006

I guess there is no way to reduce PDF file size then, other than 
reducing the quality of the image.

Thanks anyway.

Robin Becker wrote:
> Nicholas Watmough wrote:
>> I tried creating the PDF using PNGs. When saved, the PNGs were 
>> approximately 100KB or less each. But when put into a PDF,. the PDF 
>> was approximately 2MB. GIFs were about 800KB each, but the PDF was 
>> still 2MB.
>> Not sure why approx. 1.1MB of PNGs create a 2MB PDF. Seems something 
>> is going on.
>> Not sure what else I can try.
>> Nathan wrote:
> All images other than jpeg are treated equivalently; they are first 
> converted into a number of planes and then the same compression and 
> asciification is carried out on them to create pdf objects. That's 
> probably why the png and gif versions end up pretty much the same size.
> I think the reason for the size doubling is probably the use of 
> ascii85 encoding for the compressed images.
> It should be possible to eliminate the ascii85, but last time I tried 
> I got it wrong so will need to think a bit more about it.

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