leon wrote:

*** Bug 6317 has been marked as a duplicate of this bug. ***

leon wrote:

It seems to just happen at a width greater than 99px, I've added an example to
Tim Bartel's test-page for that. I tried to create a thumb of a different image
with thumb.php (as far as I understand the comments in thumb.php it uses the
same engine to create thumbs) which worked with widths >99px.

contactbox wrote:

Examples:
See: http://en.wikipedia.org/wiki/User_talk:FT2#Image_thumbnail_test

The first image is the original PNG, it doesn't show properly.
The 2nd image is identical, in GIF format, and behaves perfectly.

leon wrote:

another test page:
http://meta.wikimedia.org/wiki/User:Avatar/example-png-thumbnail/test2
crazy.

simonell wrote:

@PS That aren't the same images. One with a description of the colors which the
other doesn't have.

bill wrote:

The problem is that a height of -1 is being returned to the browser.
It seems to have been patched in the development trunk, but
can be superficially fixed by specifying both a width and a height
for the thumb
[[Image:test.png|thumb|180x180px|caption]]

I've found lots of png's with the error: "Error creating thumbnail: Invalid
thumbnail parameters"

For example: [[commons:Image:Wikipe-tan Birthday.png]] and older versions of
[[Image:Map showing NWFP and FATA.png]] (the ones sized 6325×7085)

Browser can display these images without a problem for the non-resized version

hersfoldwiki wrote:

A similar problem is occurring with jpegs as well - instead of the image, the caption is returned as a link to the image. Examples shown here, flagged with that little warning icon thingie.
[http://en.wikipedia.org/wiki/User:Hersfold/Hersfold%27s_Sandbox/Thumb_test]
Main problem, at least with this image, is that it occurs at the default size. I've seen it occur elsewhere, but I just noticed today that someone else is having a similar problem.

ayg wrote:

It's been one year since the last comment here, and I haven't heard widespread complaints about continuing problems. I'm closing WORKSFORME, reopen if it's still an issue.