File formats, tech info wanted

mercphoto

Anyone know where I can find the technical specs on the .JPG file format, and the Canon .CRW file format (as used by my dRebel) ? I'm wanting to know byte layout, and here is why.

When I shoot raw or jpg in the camera, the camera embeds exposure information about the shot. If I shot raw and import into Photoshop and have PS create a JPG for me, it does not put exposure information into the JPG. Really irks me, because now I don't have exposure information in my JPGs, which I store in iPhoto. I'm going to fix this problem by writing a program to scan the .CRW, find the exposure information, then stuff that into the .JPG.

I have the ability if I know the file structure.

Alternately, anyone know of a better way to achieve this end result?

mercphoto

Never mind on file formats
It took a lot of tracking down on the web (try googling JPG sometime and see how many hits you get), and contacting Canon tech support, it appears the information I want to know is either priveleged, or expensive.

Canon said they don't release the format of their .CRW files, and the .JPF file format is available for a nifty sum of money. But, still wouldn't mind knowing if I can make Photoshop CS keep the exposure information when it converts raw to JPG.

DavidTO

mercphoto wrote:

But, still wouldn't mind knowing if I can make Photoshop CS keep the exposure information when it converts raw to JPG.

I don't use PS for conversion, I use C1 SE, which does keep the exposure information on the resulting jpeg.