Scale-dependent and example-based grayscale stippling

►We provide an analysis of high-level processes involved in stippling and a discussion on how to support these using image-processing. ►We define a method for example-based stippling in which the stipple dot placement is based on halftoning, with a scale-dependent treatment of scanned stipple dot examples, desired output, and stipple placement. ►We define a grayscale stippling process that can faithfully reproduce the merging of stipples at middle tonal ranges, enabling of both print output in black-and-white and on-screen display in gray or tonal scales at the appropriate spatial and color resolutions, with an optional special treatment of image edges that improves the control of the placement of stipples. ►We present a description of a GPU implementation of the basic technique. ►We make a comparative analysis of the stipple dot placement statistics for both the used examples and generated synthetic stipple images.