I'm working on some code that computes weighted averages of a series
of images. I do this by loading a subset of the large image list
(maybe a dozen images at a time), computing their average, and then
saving the result image to disk. Once I'm done with that subset, I
load a new batch and repeat.
The problem is that over time, I start swapping and eventually get
memory-related overflow problems.
Here's the output of a typical memory crash:
Error in sys.excepthook:
Traceback (most recent call last):
File "/var/lib/python-support/python2.5/apport_python_hook.py", line
30, in apport_excepthook
import apport.report, apport.fileutils
File "/var/lib/python-support/python2.5/apport/__init__.py", line 1,
in <module>
from apport.report import Report
File "/var/lib/python-support/python2.5/apport/report.py", line 20,
in <module>
from problem_report import ProblemReport
File "/var/lib/python-support/python2.5/problem_report.py", line 17,
in <module>
from email.MIMEMultipart import MIMEMultipart
File "/usr/lib/python2.5/site-packages/PIL/__init__.py", line 79, in
__getattr__
File "email/mime/multipart.py", line 9, in <module>
File "email/mime/base.py", line 9, in <module>
ValueError: bad marshal data
Original exception was:
Traceback (most recent call last):
File "/home/mark/sandbox/im_retimer/retimer_tester.py", line 24, in <module>
imstacklist[i].computeBlendImg()
File "/home/mark/sandbox/im_retimer/im_retimer.py", line 80, in
computeBlendImg
self.tmpImg = Image.blend(self.blackImg, self.imObjStack[i],
self.imWeights[i])
File "/usr/lib/python2.5/site-packages/PIL/Image.py", line 1944, in blend
return im1._new(core.blend(im1.im, im2.im, alpha))
MemoryError
The thing is that I have plenty of memory for any given batch. The
problem seems to be that PIL or python is not doing a good job of
automatically flushing memory of image objects that I don't use
anymore.
So my question is: is there a way to force the flushing from memory of
image objects I no longer need? Any other ideas for managing this kind
of overflow? Over time, my program may try to load hundreds of images,
but I only need to run computations on a few at a time.
thanks
mark
--
--
Mark Wendell
_______________________________________________
Image-SIG maillist - Image-SIG@python.org
http://mail.python.org/mailman/listinfo/image-sig
