iluCompareImage compares the current image to the image having the name in Comp. If both images are identical, IL_TRUE is returned. IL_FALSE is returned if the images are not identical. The bound image before calling this function remains the bound image after calling ilCompareImage.

ILU_ILLEGAL_OPERATION - There is currently no image bound. Use ilGenImages and ilBindImage before calling this function. Another possible source of this error is if Comp is an invalid image name.

ilGenImages, ilBindImage