Save HBITMAP as PNG image using GDI?

Question

I'm looking to save an HBITMAP to a PNG image. Is this possible using only the GDI API? (I'm using C, so no GDI+.) I have only found examples like this, to save to a BMP file. Or should I use libpng and use GetDIBits?

Related question (about reading).

score 3 · Accepted Answer · answered Apr 29 '12 at 09:35

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Unfortunately, GDI does not support PNGs.

answered Apr 29 '12 at 09:35

Alexey Frunze

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Okay, so is using GetDIBits to provide data to libpng the typical way to go here? – Jonathon Reinhart Apr 29 '12 at 09:40

score 2 · Answer 2 · answered Apr 29 '12 at 12:07

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The Microsoft Windows API does not expose any c++ classes directly from DLLs - The c++ standard does not define an ABI, and as such, the calling conventions and name mangling's used are left to specific implementations to define.

As such, up until Metro at least, all "C++" interfaces supported by the Windows OS have actually been a regular dll exporting a C compatible API, and an accompyining set of c++ header files with the necessary template and inline code.

As such, GDI+ has a Flat API documented in MSDN.

answered Apr 29 '12 at 12:07

Chris Becke

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Is this answer to this or some other question? – Alexey Frunze Apr 29 '12 at 12:11
The point is, requiring a C compatible API does not exclude GDI+. – Chris Becke Apr 29 '12 at 12:16
Thanks for pointing this out! I just assumed they were actually exporting the classes. However I think libpng will be far less painful than trying to get the Flat API calls right :-) – Jonathon Reinhart Apr 29 '12 at 18:53

Save HBITMAP as PNG image using GDI?

2 Answers2