The iluColoursUsed function returns the number of colours used in the current image.

None

iluColoursUsed creates a copy of the image data, quicksorts it and counts the number of unique colours in the image. This value is returned without affecting the original image.

ILU_ILLEGAL_OPERATION - There is currently no image bound. Use ilGenImages and ilBindImage before calling this function.

ilGenImages, ilBindImage