We need an cpp functions, which utilize graphic acceleration for showing images. You can use OpegGL, DirextX or Direct3D or anything, that will be fast and will not use CPU too much. Functions should provide following functionality:
1. Loading pictures from grayscale image file (we will provide the code, which performs loading into memory)
2. Showing picture in the Drawing Context
3. Smoothly scale image (for example in OpenGL bilinear filtration should be used)
4. Change gamma, brightness, contrast of an image.
5. Applying two custom filters for image (we will provide the code)
Images size can be up to 20000x20000 pixels. Implementation of functions should work fast (not slower, than using GDI). Also it should work on common graphic cards with 64MB of memory.
When placing the bid, please suggest which graphical API you want to use.