Editing Jpeg (JFIF) headers

Greg · External Since: Jun 07, 2007 Posts: 67

Recently Vista networking/filehandling/PhotoGallery corrupted some of my jpg
files by trashing the jpg markers.

Does anyone know whether it is possible to use a text editor to replace the
headers with an intact JFIF header from an uncorrupted file so that software
can recognise it as a jpg again? Or is each header so integral to that
particular image (in terms of defining size, etc) that you can't do that?
And if it is possible, where do the Jpg headers start and end? I don't read
hexadecimal! (Or whatever that spaghetti is)

There doesn't seem to exist yet any recovery software that works for Vista
that can recover my files.

Adam Albright · External Since: Feb 03, 2007 Posts: 2515

On Wed, 8 Aug 2007 11:44:10 +1000, "Greg" <greg.munro.TakeThisOut@bigpond.com>
wrote:

>Recently Vista networking/filehandling/PhotoGallery corrupted some of my jpg
>files by trashing the jpg markers.
>
>Does anyone know whether it is possible to use a text editor to replace the
>headers with an intact JFIF header from an uncorrupted file so that software
>can recognise it as a jpg again? Or is each header so integral to that
>particular image (in terms of defining size, etc) that you can't do that?
>And if it is possible, where do the Jpg headers start and end? I don't read
>hexadecimal! (Or whatever that spaghetti is)
>
>There doesn't seem to exist yet any recovery software that works for Vista
>that can recover my files.

You're getting into the tall grass and probably at minimum need a hex
editor. There's more involved than simply substitution. If you want to
give it a shot this may help:

http://www.martinreddy.net/gfx/index-hi.html

Follow to the JPEG link under 2D bitmaps then also check out the FAQ
and tools section.

Greg · External Since: Jun 07, 2007 Posts: 67

Thanks. Not sure I can be bothered working that all out, and I don't have a
hex editor. Interesting site, but a bit out of date - hasn't been updated
for ten years and most of the links are broken. Rather nostalgic - even has
info on the good Amiga IFF (sigh).

"Adam Albright" <AA.DeleteThis@ABC.net> wrote in message
news:ipaib356is03qb2fp3v0mlv3vq6f9f4jug@4ax.com...
> On Wed, 8 Aug 2007 11:44:10 +1000, "Greg" <greg.munro.DeleteThis@bigpond.com>
> wrote:
>
>>Recently Vista networking/filehandling/PhotoGallery corrupted some of my
>>jpg
>>files by trashing the jpg markers.
>>
>>Does anyone know whether it is possible to use a text editor to replace
>>the
>>headers with an intact JFIF header from an uncorrupted file so that
>>software
>>can recognise it as a jpg again? Or is each header so integral to that
>>particular image (in terms of defining size, etc) that you can't do that?
>>And if it is possible, where do the Jpg headers start and end? I don't
>>read
>>hexadecimal! (Or whatever that spaghetti is)
>>
>>There doesn't seem to exist yet any recovery software that works for Vista
>>that can recover my files.
>
> You're getting into the tall grass and probably at minimum need a hex
> editor. There's more involved than simply substitution. If you want to
> give it a shot this may help:
>
> http://www.martinreddy.net/gfx/index-hi.html
>
> Follow to the JPEG link under 2D bitmaps then also check out the FAQ
> and tools section.
>