Local histogram-based filters may create non-photorealistic computer graphics effects. An edge-preserving smoothing filter processes a source image to generate a smoothed image. An orientation filter processes the source image to generate a smoothed orientation image. At least one of the orientation filter and the edge-preserving smoothing filter include a local histogram-based filter. The non-photorealistic effect filter may generate a fine detail image from the smoothed image and the source image. The fine detail image may be diffused according to the smoothed orientation image to generate a brush stroke image. The brush stroke image is combined with a base image to create a non-photorealistic image. Local histogram-based filters include a closest mode, a local median, and a dominant mode filter. Local histogram-based filters are determined by convolving a neighborhood filter with one or more offset-kernel images, each based on the application of a shifted tonal filter kernel to the source image.