ofxCvGrayscaleImage without bg.


I am playing with opencv examples and really loving them and I do have one question.
Say I am doing threshold on the video and I was wondering if there’s anyway not draw the black background but only the threshold of the foreground image(which is usually white). Basically I still want to see my stage and only be able to see the white thresold. I looked the draw functions but it looks like there’s not one.

I would appreciate any directions regarding this.

i think the best way to do this would be to copy the image into a grayscale image with alpha - not sure whether ofxCvGrayscaleImage supports alpha or not - and then copy the luminance channel into the alpha channel. they key is to have 0 alpha on the pixels that are black, and any way you can achieve that should get you what you want.