[Mono-winforms-list] libgdiplus/System.Drawing patch: native support for indexed Bitmaps

Fabian Luque Fabian Luque <fabianluque@gmail.com>
Wed, 16 Mar 2005 18:02:36 -0300

> The problem here is that because the TIFF format is massive and complex, I
> decided to postpone indexed TIFF loading support for a later patch. This
> patch does not alter the way the TIFF codec loads TIFF files, and as such
> they are upsampled to 32bpp at load time. Then, when you go to save the
> Bitmap, the PNG codec says "hmm, this is a 32-bpp RGB Bitmap object, so
> I'll make a 24-bit RGB PNG file".

> Is it possible for you to pre-convert the TIFFs to another format, like BMP
> or PNG, or is this the whole point of what you were trying to accomplish
> using System.Drawing? :-)

Well... that's what I'm trying to do. Anyway, I can convert the TIFF
to PNG with some
other tool but when I try to load it I get an error from libpng.
Something about the palette is not valid.

Maybe there's something wrong in the patch because if I use SVN head
libgdiplus the code works just fine, except for saving 32 bits files.

The web app I'm developing takes TIFFs, converts them to PNGs and when
a client wants to access the image, resize it according to the screen

Any help would be appreciated.

Thanks Jonathan,

Fabian Luque