问题
If I do the following
for root, dirs, files in os.walk(myDir):
for myFile in files:
with Image(filename=myFile) as img:
with Image(image=img) as main:
print main.sequence[0].width
I end up with memory faults using Wand.
I'm sure its the .sequence part. If I remove that, its fine. I've read all I can find on sequence, how its an Image vs SingleImage.
The SingleImage sequence part stays in memory. I've tried to use the following:
main.sequence[0].destroy()
but it does not get rid of the image in the memory.
I'm processing thousands of files, but after just a few dozen I get segmentation faults.
I'm pretty sure its closing the 'main' Image. Just not the main.sequence SingleImage.
Is there a way to forcibly close that?
I should say I've also tried this
with Image(image=img.sequence[0]) as main:
thinking the With statement would close it indirectly. But it does not.
Can anyone help?
回答1:
First things first - file a bug with wand. The wand.image.Image.destroy
is not cleaning up wand.image.Sequence
in the event an image sequence was allocated. Good find!
You are absolutely correct with main.sequence[0].destroy()
; however, your only freeing the first allocated SingleImage
in the sequence. So img.sequence[1:]
is still setting in memory. A not-so-elegant solution would be to iterate & destroy all SingleImage
's.
for root, dirs, files in os.walk(myDir):
for myFile in files:
with Image(filename=myFile) as img:
with Image(image=img) as main:
first = True
for frame in main.sequence:
if first:
print frame.width
first = False
frame.destroy()
comment: Reading an image from file to img
, copying the data to main
, and creating sub-images in a sequence seems very memory intensive. I'm sure your doing a lot more than identifying the image width, but can that be rewritten? Imagemagick does have a ping method ( not yet implemented in wand
) which doesn't read image data into memory.
来源:https://stackoverflow.com/questions/30100956/python-wand-sequence-not-clearing-from-memory