Modify jpeg, with VB ?

[eequalsmc2plus1]

Hi

Anyone know something about jpeg file formats and whether it would be possible for me to write an exe that would take a jpeg and add another picture to it ?
If yes, can you give me some pointers ? What to look up etc.

Thanks
Damian

 

[sunaj]

yes, but you need some software that can write a jpg file.
There is a free demo version at

http://www.mainconcept.com/downloads.shtml

but it adds a watermark to the jpg. I use ImgX (

http://www.imgx.com)

which is a bit overkill for just saving jpg but it does the job nicely.

Sunaj
'The gap between theory and practice is not as wide in theory as it is in practice'

 

[eequalsmc2plus1]

So wouldnt it be possible to write that code in VB that adds the watermark to the jpeg ?
If your can figure out the jpeg format and all that stuff, it should be possible ??? Right ?

 

[sunaj]

of course.... Sunaj
'The gap between theory and practice is not as wide in theory as it is in practice'

 

[eequalsmc2plus1]

So where would you begin ?
Finding out about jpeg headers now.

 

[sunaj]

I do not know of any places where the jpg format is described in such detail that you can replicate it.
I suspect that it is not an easy job, the jpg format is no where as simple as a bitmap or similar.....
However if you prove me wrong I would me very interested to have a look at the solution Sunaj
'The gap between theory and practice is not as wide in theory as it is in practice'

 

[johnwm]

For basics on how it works:

http://www.prepressure.com/techno/compressionjpeg.htm

For a 'C' library try:

http://freshmeat.net/projects/libjpeg/?topic_id=105,809

For several other links to JPG details:

http://myfileformats.com/search.php?cat_id=20&cat_name=Graphics files&start=10

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[MichaelRed]

There was (long away and far ago), a book / publication which specialized in the arcania of file formats. I haven't noticed anything recently (ten years?), but the original had everthing from dbase to tiff, along with sample code to read most of these and translate the results into 'useful' information. I realize that many file formats are considered proprietary, however if / when they are decoded without 'inside' information, it is my understanding that one would be free to divulge the information freely. It SEEMS, to me, that there would still be a market for this (although I no longer work in graphics).

MichaelRed
m.red@att.net

Searching for employment in all the wrong places