Hello,
Vision Builder functions usually work with a certain image type. For example, all the functions listed under Binary (in the menubar) will only work with binary images. Likewise, color functions will work for color images and grayscale will work for grayscale images.
You can convert a color image into a grayscale by extracting a color plane and a grayscale image can be converted to binary using the threshold function.
Hope this helps!
Regards,
Yusuf C.
Applications Engineering
National Instruments