Edward Vermillion wrote:
Sorry to reply to this message but I wanted the OP to find it too...
On Jun 23, 2005, at 9:42 AM, Jack Jackson wrote:
[snip]
Through your help I was able to validate image files using
getimagesize() and have made a nice script to upload and rename images.
[\snip]
I've been meaning to post a reply to a problem I ran into a while back
that included validating images with getimagesize(). I've seen a few
posts from folks saying this is the way to go and just want to share my
experiences.
My original problem was that a script I had for batch generating
thumbnails from uploaded images was running out of memory. With Richard
Lynch's help I was able to track the problem to createimagefromjpeg()
using an unholy amount of memory on one particular file, a file that had
passed through getimagesize() with no problems.
What I found was that if an image ( in this case a jpeg ) is corrupted,
but just barely, getimagesize() will let it through. Just for the record
I could open it up in Photoshop and that's how I discovered that it was
corrupted, the last ten or fifteen rows on the image were gone.
Photoshop showed an uncompressed file size of 11M for this image. But
what I had to end up doing is setting my memory limit to 48M before
createimagefromjpeg() could get enough memory to work with that it
finally failed.
Just a heads up to anyone that's using getimagesize() to verify an image
before running it through createimagefromjpeg(), just because it passes
getimagesize() doesn't necessarily mean it's a good image.
Edward Vermillion
evermillion@xxxxxxxxxxxx
Thanks for telling me about that, Edward. I apprecate it. Actually in
this case I was using it only to verify that it was something like an
image to validate the file type before allowing it on the server. But
you raise a very good point and I appreciate it.
JJ
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