[Discuss] Peculiar JPEG Image behaviour -- Off Topic?

[Murray Strome]

R. Langkamer wrote:
> On 5/24/07 8:23 AM, Murray Strome wrote:
>
>> i received three JPEG images in full resolution sent by someone with 
>> a Mac computer. They were all "full resolution", and a bit over 2 MB 
>> is size.  I tried to open them with the GIMP (2.2).  In one case, it 
>> took about 30 minutes to open. On the lower bar, it said the 
>> background was about 900MB.  During the opening of the image, the 
>> computer pretty well ground to a halt. I did some editing and tried 
>> to save it again, but after an hour of churning away, using 85% of 
>> the computer's 1GB RAM, it still wasn't saved and I was really unable 
>> to do anything else with the computer because the response was so 
>> slow, so I killed the application.  I was able to open it using 
>> Gwenview, then save it, then open it with the GIMP. It was still 
>> pretty big, so I created a new file, copied and pasted the image I 
>> had opened with the GIMP into it, then  saved it.  That image opened OK.
>> One of the images gave this error when trying to open it in the GIMP:
>>
>> Opening '/tmp/P5010021.JPG' failed: Plug-In could not open image
>>
>> I found I could upload the image to Google's Picasa2 with no problem. 
>> I downloaded the image from the website, tried to open it with the 
>> GIMP and had the same problem. I can preview it OK, and the EXIF data 
>> under properties all looks OK. There must be something about the JPEG 
>> format full resolution images are saved with the Mac to cause this (I 
>> think).
>>
>> I found the same problem when I tried to open it with the GIMP in 
>> Windows.
>>
>> Does anyone have any idea as to what is going on?  I have never seen 
>> anything like this before.
>>
>> Murray
>
>
>     Based on the additional information I found at this URI :
>
> http://bugs.php.net/20560
>
>     I would surmise that you attempted to open the thumbnail file as 
> AppleMark typically appears in the header of thumbnail images made in 
> MacOS X. Otherwise, the image is an Apple PICT file according to this 
> URI :
>
> http://www.computerbuddies.us/what_is_a_jpg.htm
>
>     That being said, if the image you opened was in fact direct from 
> the camera, then I would say that the email transmission corrupted the 
> image possibly and thusly you are experiencing problems decoding it in 
> gimp.
>
>     One final bit of important information, how many files appeared in 
> your email from the sender? Of these attachments, which did you 
> attempt to open?
>
Three files were in the E-mail. I have since received the iPhoto LARGE 
versions of the images. These are quite a bit smaller (and, in fact, a 
bit lower resolution than I would have liked).  Two of the files opened 
just fine with the GIMP, but one still gives that GIMP error message 
(running version 2.2).  I can certainly VIEW all the images with no 
problem, upload them to an Album in Google's Picasa2 and view them from 
there -- no problem.  I will try Alan's suggestion of looking at the HEX 
for the header of the images to see what is there.  It may be something 
peculiar that GIMP doesn't like, but which Konqueror, Gwenview, Google, 
etc. all ignore.  The background in these images is still large; the 
images are  960X1280 but the background is 171MB which seems 
ridiculous!  I am not sure where GIMP gets this information, or how it 
is used -- but such huge backgrounds sure do slow down the loading and 
saving!

Murray