**** Warning: considering '0000000000 XXXXX n' as a free entry.

https://codeyarns.com/2014/03/10/free-entry-warning-with-ghostscript-and-imagemagick/

> This warning turns out to be from the Ghostscript program, which is used by
> ImageMagick internally to perform this format conversion. This page explains
> that this error has been fixed in a recent version of Ghostscript. I used a
> newer version of Ubuntu, that is 13.11, that had a newer version of gs and I
> was able to perform the format conversion. It still gave off the warning,
> but the conversion was done.

Image.py tells imagemagick to convert to stdout.
Warnings are also returned via stdout before actual rendering.