Tangent-Based Binary Image Abstraction

We present a tangent flow-based image abstraction framework that turns a color or grayscale image into a two-tone image, which contains only black and white color, but retains sufficient information such that the viewer can still recognize the main content of the original image by observing the output of a two-tone image. Usually, the relevant visual information is presented by the edge. Thus, the algorithm will enhance the edge content first by the tangent flow to preserve its detail. We use filters to smooth the input image to reduce the contrast in low contrast regions and enhance some important features. Then we turn the image into a two-tone image as output. We can reduce the size of the image significantly but retain sufficient information to capture the main point of the image through our method. At the end of our process, we provide a smoothing step to smooth the two-tone image. Through this step, we can get an artistic black-and-white image.