How to get game screen pixels (like FRAPS)?

You probably want a proxy DLL. Some old example code can be found at http://www.codeguru.com/cpp/g-m/directx/directx8/article.php/c11453

Note that if you want to be able to handle all applications you'll need several proxy DLLs to hook the various versions of D3D and OpenGL.

If you just want a screen shot then just press the print screen button which grabs an image of the whole screen and puts it in the clipboard.

I don't actually want to be pressing print screen because I need my application to be automated. I also do not want to be saving the pixel color data on the screen to the hard drive, I just need to information in memory so that I can perform some calculations on it.

I wonder if I could write a simple Windows program that simulates a print screen key press, have windows capture the data for me and save it in the clipboard and then somehow gain access to the clip board data so that I can extract the pixel data that is on the screen.

This may be a little slow since it would be capturing everything on the screen, but I only want to get about 100 pixels from the screen, nothing more.