Hello,
I started to work on a patch for Inkscape to be able to export embedded or linked image in SVG to be exported in PDF with their correct MIME type and original raw data. Current code is exporting JPG file to bitmap file by storing the gdk pixbuf data, which results in heavy PDF files. I am still struggling with the cairo-renderer code to fully understand it.
Two bugs related to the issue, I mentionned:
https://bugs.launchpad.net/inkscape/+bug/168708 https://bugzilla.mozilla.org/show_bug.cgi?id=612844
Please find attached my patch for a first step toward this new feature. Note, currently it is only written for JPG file. I'll add later a way to correctly work out the MIME type of images.
I am now able to add the original MIME data on the cairo_image_surface with 'cairo_surface_set_mime_data'. But apparently the rest of the exporter code is redrawing the surface which causes the original data to be dropped, and the JPG images are still stored as bitmaps in the final PDF. According to Cairo doc on MIME data : "Caution: the associated MIME data will be discarded if you draw on the surface afterwards."
I do not find which part of the renderer code is redrawing the image surface. Could one of you help me with this issue which would fix an annoying bug ?
Related to that. I wrote/modified a minimal test example with cairo which works nicely to export JPG file in PDF, see related discussion on Cairo:
http://lists.cairographics.org/archives/cairo/2013-June/024372.html
Thanks for your help, François Bianco