Which format are FS2004 skins saved as?

[Magneto]

I'm hoping I can get some help.  First, I have DXTBmp, Photoshop 5.5, Corel Photopaint 9, and others for working with graphics.

Ok.. I cannot open any of the FS2004 plane skin textures using photoshop or photopaint. I have DXTBmp for that. But DXT doesn't seem to tell me what special type of bmp I'm opening, and for the life of me I cannot get any edited version of the file to save at the correct file size.  
For instance.. the skin will open, saying it's 1024x1024. It's not a "normal" bmp, or photoshop would open it.
No matter what I try, the file size of my new bmp (or even trying to resave the original with no editing) is always larger.  Are these textures compressed or something?  
Is there a plugin (or something) for Photoshop or photopaint that will allow them to read and open these files??
What the heck am I doing wrong?

Thank you..
Mag...

[Felix/FFDS]

If I recall, DXTbmp should tell you the format of the original image.

At any rate, depending on the use, you're looking at DXT3 format for the FS2004 bitmaps.

As long as you DON'T save as 24bit color, you should be all right.

[Magneto]

If I recall, DXTbmp should tell you the format of the original image.

At any rate, depending on the use, you're looking at DXT3 format for the FS2004 bitmaps.

As long as you DON'T save as 24bit color, you should be all right.

Thanks for the reply. DXTbmp is showing one of the C172 skins as being :
c172_c.bmp.. 1024x1024, opaque, 8 mips, DXT 1 format.

What would be the best way to get this image to (let's say) Photoshop 5.5, do some tinkering with it, then get it back to the proper format and size for use with FS2004?  
I've done some graphics work and editing before, but mostly with normal bmps, targas, gifs, jpgs, etc..
Even when I save the bmp as an 8-bit, indexed color , uncompressed image, the file size is still larger than the original was.
This FS format stuff is very confusing.

I'd really appreciate any help or some links to information that would explain some of this. Most of the tutorials I've run across explain how to paint and edit, but don't go into detail about getting the file back to it's proper format.

Mag...

[Felix/FFDS]

If I recall, the DXTbmp documentation has a discussion on the different formats used by FS over the versions.

Typically, once you open an image in DXTbmp, you can send it to your paint program then when you close it, it comes back to DXTbmp.

Alternatively, use DXTbmp to convert it to say, a 32-bit normal bitmap and save it so you can open it normally.

[Magneto]

If I recall, the DXTbmp documentation has a discussion on the different formats used by FS over the versions.

Typically, once you open an image in DXTbmp, you can send it to your paint program then when you close it, it comes back to DXTbmp.

Alternatively, use DXTbmp to convert it to say, a 32-bit normal bitmap and save it so you can open it normally.

Felix.. thank you for helping.  I will do some reading and see what happens.  I did do a test on part of the C172's virtual instrument panel, by adding a small area of noise to it.   I then saved it as an "extended format" bmp, and installed it into FS.  It did work, however the whole cockpit now has a greenish tint to it, even though all I added was a touch of mono noise to a small area of the graphic.  
The file sizes are larger, and Photoshop will now open my newly created file, whereas it will not open the original. There's something different between the two, but I haven't found it.
I'll see what I can find out, maybe post back here later with my results.
Thank you ...
Mag...