Halftoning Comic style

Halftone (semi-tuned method) is a non-realistic Paster. It is used to simulate pen-and-ink styles ). It was first originated from the printing of White Paper and black text books. All continuous color images, whether color or gray, can only be expressed in black and white, therefore, the overall brightness distribution must be roughly the same.

Halftone Screen is the most basic factor for determining the visual effect in the semi-tuning method. It is a grayscale texture containing a threshold value. To create a half-tuned image from a given input image, compare the brightness of each pixel with the corresponding threshold value in halftone screen, writes black or white pixels based on the comparison result. Suppose H is the threshold of Halftone Screen and L is the target brightness. We can write the threshold function:

H> (1-L )? 1:0

Here, (1-l) indicates the darkness (darkness ).

Below are some (Implemented Using OpenGL + CG, and the red ball is the light source ):