[racket] pdf-dc%: Generating a pdf with image embedded in jpeg format?

From: Daniel Prager (daniel.a.prager at gmail.com)
Date: Mon Dec 8 18:44:24 EST 2014

A few quick experiments suggest that Racket/Cairo can/does embed a png
representation within the pdf, but saves a bitmap with jpeg representation
by expanding out to a more naive format. E.g.

   - Racket -> png: 2738 bytes
   - Racket -> pdf: 2995 bytes
   - png -> ImageMagick -> jpeg: 2024 bytes
   - jpeg -> Racket -> pdf: 8854 bytes!! ;-(

* * *

A bit of Googling gives some confirmation (and hope):

>From 2007 (

> So, there's this bug against eog (GNOME image viewer) [1] about images
> printed to PDF are huge. The reason of course is that cairo embeds images
> as PNG. We need to find a solution to this.

The October 2014 release  of Cairo 1.14.0 describes the following feature:

> Support JBIG2 mime data in PDF. This allows embedding of more compressed
> JPEG formats within PDF, rather than including the full uncompressed image.
> See: http://cairographics.org/news/cairo-1.14.0/

* * *

I can't find anything in the online docs about the Cairo API that
explicitly reference JPEG or JBIG2.

Is anyone running Cairo 1.14.0 (or later), and does it "just work" in this

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