Re: Size of PDF with lots of images
Behdad Esfahbod <[email protected]>
| Newsgroups | gmane.comp.lib.cairo |
|---|---|
| Message-ID | <[email protected]> |
On 14-01-17 04:20 AM, Adrian Johnson wrote: > On 17/01/14 06:45, Simon Sapin wrote: >> On 16/01/2014 19:57, Adrian Johnson wrote: >>>> If your images were in a format that the PDF backend supports [2] (which >>>> includes JPEG but not PNG), you could use cairo_surface_set_mime_data() >>>> to have cairo store the original image data (almost) as-is in PDF, >>>> without re-compressing. Although I expect that lossy JPEG may not look >>>> nice for these specific images. >>> Yes, jpeg images are the most likely reason for the increase in size. >>> >>> I'm not sure what you mean by "lossy JPEG may not look >>> nice for these specific images". The jpeg data is stored exactly as >>> provided to cairo_surface_set_mime_data() so there will be no loss of >>> image quality. >> >> Behdad’s images are PNG here, not JPEG. They are computer-generated with >> sharp edges, the kind where JPEG does not do well. >> > > I see two jpegs in his git repo. Yes, the background image is a 0.5MB JPEG. But the other 13.5MB are PNGs. Now it occurred to me that I also use a surface cache and that's why the background image wasn't reembedded 150 times! I was under the impression that cairo's being smart... I still think it should try to be smart by hashing images and reusing them. -- behdad http://behdad.org/ -- cairo mailing list [email protected] http://lists.cairographics.org/mailman/listinfo/cairo