Certain image when uploaded into Confluence, the thumbnails creation are color inverted.

The details are captured in this screen cast: http://screencast.com/t/cBwnvg0Q

However, this issue is image specific and not easily reproducible with any images regardless of the image extension.

My guess is that Confluence is using an image library that does not recognized this special image type. The same issue is not observed when the same image is attached to Gmail or Flickr.

Same issue is also observed in JIRA.

Workaround:

Convert the image to another image format would solve the problem.