CxImage is a C++ class that can load, save, display, transform images in a very simple and fast way.
CxImage is open source and licensed under the zlib license. In a nutshell, this means that you can use the code however you wish, as long as you don't claim it as your own.
With more than 200 functions, and with comprehensive working demos, CxImage offers all the tools to build simple image processing applications on a fast learning curve. Supported file formats are: BMP, GIF, ICO, CUR, JBG, JPG, JPC, JP2, PCX, PGX, PNG, PNM, RAS, SKA, TGA, TIF, WBMP, WMF, RAW, CRW, NEF, CR2, DNG, ORF, ARW, ERF, 3FR, DCR, X3F, MEF, RAF, MRW, PEF, SR2.
Cximage is highly portable and has been tested with Visual C++ 6 / 2008, C++ Builder 3 / 6, MinGW on Windows, and with gcc 3.3.2 on Linux. The library can be linked statically, or through a DLL or an activex component.
amsn has a library that provides a Tcl/tk extension to make use of the cximage library.