GIMP Users -- Re: OT - Having Problems Displaying Image Thumbnails

On Sat, Oct 23, 2010 at 11:27 AM, Frank Gore <gore@xxxxxxxxxxxxxxxxxx> wrote:

On Sat, Oct 23, 2010 at 2:11 PM, Mark Phillips
<mark@xxxxxxxxxxxxxxxxxxxxx> wrote:
> My apologies for this OT post, but I need some help from an "image expert",
> and I thought the Gimp list might have one or two.
> When I upload images from a friend's digital camera, a Java web app is not
> able to create thumbnails (they appear black with the title of the image in
> the image area). However, clicking on the missing thumbnail renders the full
> image. When I upload images from a different camera, the same app generates
> the thumbnail and also renders the full image. Is there a special setting
> that camera's have to have set to allow thumbnails to be created? Both file
> types are jpeg. I am not seeing any error messages from the app.

Yep, definitely off-topic :p

Those applications you mentioned probably aren't generating
thumbnails. They're just using the existing thumbnail that's embedded
in the file. Most cameras embed a thumbnail in the JPG file, some do
not. Your friend's camera probably just doesn't have those thumbnails
embedded.

I tested a "bad" image and a "good" image using Jeffrey's Exif viewer (http://regex.info/exif.cgi), and both images had an embedded thumbnail. The only difference I saw in the two files from the two cameras was that the image from the bad camera had this warning;thumbnail size does not match image size. The image size from the bad camera was 5,184 × 3,456 and the thumbnail was 160 X 120. I think this warning is referring to aspect ratio.

Anyway, I could not see any difference in the data from both pictures, but then I am not an image expert.

To keep this on-topic: Gimp and most other image editors have an
option to include a thumbnail when saving a JPG file. I typically
disable this option for web graphics to make the file size smaller.

--
Frank Gore
THE place to talk photography!
www.friendlyphotozone.com