What causes this error in .jpg's?

mdmarshall.RemoveThis@my-deja.com wrote:
: Just got some pics from my Brother-in-law, three .jpg files. They're
: big, over 2 megs each, but something's wrong. Only about the top
: fourth of the picture is visible, the rest is a field of white dots on
: a brown background. I believe the background is just a repeated color
: from the picture.

: Am I making any sense? B-) I guess I could post a sample, but I'm
: hoping this will ring a bell with someone.

: I've seen this before on the 'net, does anyone know what causes it?

: Thanks, all!

In a JPEG file there is a header that tells the software the size of the
image (in part). Then there is a mass of digital data that defines the
image contents. If the data is not enough to fill the space defined in the
header, the rest of the space is either filled with random data (or
leftovers on the HD from previous data blocks) or an endless repete of the
last block of data. So either the header data was impaired (defining a
space larger than the data available) or the data was impaired with not
enough data transferred, or an "end of file" marker in the middle of the
data string. Either way it boils down to a corrupted file. This corruption
could be at the sending computer, durring the transfer, durring the
download to your computer, or on your hard drive. I know that this is a
VERY simplified explaination of the JPEG procedure, but for this question
it is enough to understand the problem.

Occasionally I have had one of the corrupted photos that fell under the
"incorrect EOF marker location" that one display software could read past
while others could not. But your best bet is to request a resend of the
photo. Possibly even a ZIP of the photo might help ensure the proper
transmission as the ZIP decoder has loads of check and double check
procedures to help ensure a complete file. The file will either unzip
correctly or it won't, no half measures.

Randy

==========
Randy Berbaum
Champaign, IL
 >> Stay informed about: What causes this error in .jpg's? 

mdmarshall DeleteThis @my-deja.com wrote:
 > Just got some pics from my Brother-in-law, three .jpg files. They're
 > big, over 2 megs each, but something's wrong. Only about the top
 > fourth of the picture is visible, the rest is a field of white dots on
 > a brown background. I believe the background is just a repeated color
 > from the picture.
 >
 > Am I making any sense? B-) I guess I could post a sample, but I'm
 > hoping this will ring a bell with someone.
 >
 > I've seen this before on the 'net, does anyone know what causes it?
 >
 > Thanks, all!
 >
 > Mike
 > O-
 >
corrupted .jpg file. Bad download.


--
Ron Hunter rphunter DeleteThis @charter.net<!-- ~MESSAGE_AFTER~ -->
 >> Stay informed about: What causes this error in .jpg's? 

On 17 Apr 2005 22:12:43 -0700, mdmarshall RemoveThis @my-deja.com wrote:
 > Just got some pics from my Brother-in-law, three .jpg files.

How did you "got" them? If it was via ftp, did you forget to
set "B"inary before the "GET"? That'll do it.

 > They're
 > big, over 2 megs each, but something's wrong. Only about the top
 > fourth of the picture is visible, the rest is a field of white dots on
 > a brown background. I believe the background is just a repeated color
 > from the picture.

Jonesy
--
| Marvin L Jones | jonz | W3DHJ | linux
| Gunnison, Colorado | @ | Jonesy | OS/2 __
| 7,703' -- 2,345m | config.com | DM68mn SK<!-- ~MESSAGE_AFTER~ -->
 >> Stay informed about: What causes this error in .jpg's? 

On 17 Apr 2005 22:12:43 -0700, mdmarshall.DeleteThis@my-deja.com wrote:
Could be several things.. one that sprimgs to mind..are the files
getting 'clipped' by either your or his server?
 >Just got some pics from my Brother-in-law, three .jpg files. They're
 >big, over 2 megs each, but something's wrong. Only about the top
 >fourth of the picture is visible, the rest is a field of white dots on
 >a brown background. I believe the background is just a repeated color
 >from the picture.
 >
 >Am I making any sense? B-) I guess I could post a sample, but I'm
 >hoping this will ring a bell with someone.
 >
 >I've seen this before on the 'net, does anyone know what causes it?
 >
 >Thanks, all!
 >
 >Mike
 >O-<!-- ~MESSAGE_AFTER~ -->
 >> Stay informed about: What causes this error in .jpg's? 

Kevin McMurtrie wrote:

  >> Only about the top
  >>fourth of the picture is visible, the rest is a field of white dots on
  >>a brown background.
 >
 > They're damaged by a software bug or faulty storage hardware.

Unless the specific problem described can only be caused by file corruption, it's
also possible that the files are fine but there are issues with whatever program is
being used to view them. That the OP has "seen this before on the 'net" could support
that cause if he was also viewing the downloaded pics with his browser or the mail
client associated with it. I sometimes have issues with netscape mangling an image
when the file is fine. If the image displays properly in any program or exhibits the
same or similar behavior in multiple programs he should have his answer.

--
Steve

The above can be construed as personal opinion in the absence of a reasonable
belief that it was intended as a statement of fact.

If you want a reply to reach me, remove the SPAMTRAP from the address.<!-- ~MESSAGE_AFTER~ -->
 >> Stay informed about: What causes this error in .jpg's?