Write image as Indexed PNG C#

[Steve_]

Hi, I have an instance of Bitmap that I want to save as an PNG with Indexed colour mode. How can I do this in .NET? Thanks, Steve

[buachaill cliste]

Don't know about indexed colour as I've never had the necessity to do it before and google might help ;) but this:

Bitmap bmp = new Bitmap(x,y);
bmp.Save("c:\\bmp", System.Drawing.Imaging.ImageFormat.Png);

[Lost User]

That always saves as ARGB png as far as I know..

[buachaill cliste]

Oh ok. I didn't know :-D Just tryin' to help :)

[Luc Pattyn]

Hi, I don't think .NET supports indexed colors for PNG. This MSDN page[^] says PNG needs 0 bytes for parameters, so there is nothing to choose from. :)

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[Steve_]

For anyone else who wants to achieve this, the FreeImage project provides support for a large number of image codecs and colour modes and has bindings for C#. It is what I used to create a PNG8 file. Steve