memory for imagemagick

[ukos-git]

I ran into memory issues when using scaling factor 4:

montage-im6.q16: DistributedPixelCache '127.0.0.1' @ error/distribute-cache.c/ConnectPixelCacheServer/244.
montage-im6.q16: cache resources exhausted `assembled/background_4.png' @ error/cache.c/OpenPixelCache/3984.
montage-im6.q16: too many exceptions (exception processing suspended).
Traceback (most recent call last):
  File "extract_metabol.py", line 95, in <module>
    tempimg = Image.open(filename)
  File "/usr/lib/python3/dist-packages/PIL/Image.py", line 2590, in open
    % (filename if filename else fp))
OSError: cannot identify image file 'assembled/background_4.png'

I had to update imagemagick configuration file according to this issue:

diff /etc/ImageMagick-6/policy.xml /etc/ImageMagick-6/policy.xml.lowres 
53,58c53,58
<   <policy domain="resource" name="memory" value="4GiB"/>
<   <policy domain="resource" name="map" value="8GiB"/>
<   <policy domain="resource" name="width" value="256KP"/>
<   <policy domain="resource" name="height" value="256KP"/>
<   <policy domain="resource" name="area" value="2GP"/>
<   <policy domain="resource" name="disk" value="16GiB"/>
---
>   <policy domain="resource" name="memory" value="256MiB"/>
>   <policy domain="resource" name="map" value="512MiB"/>
>   <policy domain="resource" name="width" value="16KP"/>
>   <policy domain="resource" name="height" value="16KP"/>
>   <policy domain="resource" name="area" value="128MB"/>
>   <policy domain="resource" name="disk" value="1GiB"/>

We could check for correct settings using grep at the beginning of the script, but to maintain OSX executability, we would also need to check for the current system.

on linux the file is /etc/ImageMagick-6/policy.xml
so we would use something like

memor="$(grep -e "name=\"memory\"" /etc/ImageMagick-6/policy.xml | sed -r 's/^.*value=\"([^\"]+)\".*$/\1/g')"

to get the current imagemagick memory limit using bash. Maybe a make script could simplifiy the job here.
What do you think?

[usnish]

It's been quite a long while since I've looked at this code -- I think you're spot on re: the config file, and about writing a make script. Currently on clinical clerkships in medical school so extremely short on time, but if you want to take a crack definitely go for it!!