1. i have 8bpp grayscale image.
2. when i load the image and save it becomes 24bpp color.
3. i need to maintain 8bpp grayscale formt.
4. i'm using vb.net
5. and one more thing - the original image have jpg annotation -
FFE0... when i save the picture the annotation desapeer.

Hi shmuliknaaman-ga,
   It appears that the System.Drawing automatically convert the loaded
image to 32 bit. If you want to maintain a color depth of 8 bits, take
a look at the code provided in the following articles:
    - MS KnowledgeBase Articles
         -[315780] HOWTO: Save a .gif File with a New Color Table By
Using GDI+
          ( http://support.microsoft.com/default.aspx?scid=kb;[LN];315780
)

         -[319591]HOW TO: Save a .gif File with a New Color Table By
Using Visual Basic .NET
           ( http://support.microsoft.com/default.aspx?scid=kb;[LN];319591
)

    - Newsgroup Postings
         - Resize and Maintain important TIFF Properties
           (http://www.dotnet247.com/247reference/msgs/26/133178.aspx)

         - Subject: Resizing without losing the pixel depth....
           Newsgroup: microsoft.public.dotnet.framework.drawing
           ( http://groups.google.com/groups?threadm=uEKAUGzmCHA.2276%40TK2MSFTNGP09)

Although the above postings refer to GIF and TIF file formats, you
should be able to modify the given code to work with your file format.
Hope this helps.
Regards,
Theta-ga
:-)