On Sun, Jul 22, 2012 at 7:45 AM, Stefan Stavrev <[email protected]> wrote: > For both grayscale and RGB images, adjusting brightness > means adding/subtracting a constant from all pixels. > > I am not sure if I should add such function as I said in my proposal. > The API user can do it himself, but maybe I should do it for > the sake of the command line user?
The command line user can already achieve this, though in a somewhat clumsy way. For example: oiiotool A.png --pattern constant=0.1,0.1,0.1 640x480 3 --add -o B.png will add 0.1 to each channel of a three channel image A. A lot of the clumsiness comes from having to know the size of A (640x480, 3 channel), just to construct a constant image of the same size. It would be nice to have a way of dealing with such "scalar" quantities in a generic way in oiiotool. One possibility would be to declare that 1x1 images act as scalars, and broadcast that single pixel across every pixel of the other image in a pointwise manner. Then we could write something like oiiotool A.png --pattern constant=0.1,0.1,0.1 1x1 3 --add -o B.png Question for the list: Is this a crazy idea? Would it have other undesired side effects? It would surely introduce a few more special cases into the implementation of each binary operation... ~Chris _______________________________________________ Oiio-dev mailing list [email protected] http://lists.openimageio.org/listinfo.cgi/oiio-dev-openimageio.org
