Photo to Cartoon?

Does anyone here know how to use OF to convert portrait photos into line drawings with just line contours? Much like converting a human face into a cartoon…

Maybe more specifically what opencv functions should i call?

it’s not so easy, actually. a lot of what makes a cartoon work happens within the human brain: the talent/experience of the animator knows which lines are necessary to evoke a face, and which can be left out. unfortunately, a computer cannot make that judgement.

however, you can do a kind of a fake cartoon effect with an edge/line detection algorithm, eg the Canny edge detection filter, and/or by convoluting your image with convolution kernels tuned to find particular kinds of lines. there is a pre-made canny edge detection function in OpenCV, i forget the exact name. there are other tricks to do with shading, and (stereotypically) a paper surface effect is sometimes applied as a base texture.