Importance driven halftoning

Most halftoning techniques have been primarily concerned with achieving an accurate reproduction of local grayscale intensities while avoiding the int roduction of artifacts. A secondary concern in halftoning has been the pres ervation of edges in the halftoned image. In this paper, we will introduce a new halftoning technique that utilizes a bandpass pyramid to achieve an a ccurate reproduction of important attributes in the image. Ink is distribut ed through the bandpass pyramid primarily according to a user defined impor tance function. This technique has three main characteristics. First, our t echnique can produce results similar to many other halftoning techniques by allowing a generic importance function to be specified If the chosen impor tance function is average intensity we obtain results similar to traditiona l halftoning. We also show how the importance function can be changed to hi ghlight areas with high variance. Second, in addition to changing the impor tance function, the drawing primitives can also be changed. By using line s egments instead of single pixels as drawing primitives we illustrate how ed ge enhancement cart be achieved. Third, this technique allows the user to e asily limit the number drawing primitives used. This is useful in limited r esource rendering. In addition to providing a tailorable halftoning technique our method can e asily be adapted to produce two tone non-photorealistic (NPR) images. We il lustrate this by showing how sketched effects can be achieved by aligning t he drawing primitives according to different image attributes.