Abstract: Techniques described herein convert a plurality of digital images into an image or images more amenable to data compression. In one embodiment, an ordered collection of input digital images is provided. A first digital image from the ordered collection is identified as a base image, and an empty image strip is formed. For each second digital image from the ordered collection, and upon a condition in which the second image is the base image, the base image is appended to the image strip. Upon a condition in which the second image is not the base image, a difference image is computed from the base image and the second image and appended to the difference image to the image strip. Quantization and conventional image compression may be applied to the image strip to produce a compressed image strip.

Abstract: Techniques described herein convert digital images into images suitable for use as coloring book pages and the like. The techniques include applying a smoothing operator to at least one channel image of a digital input image to form at least one smoothed image. A scaling operator is then applied to the at least one smoothed image to form at least one scaled image. A tone equalization operator is then applied to the at least one scaled image to form at least one equalized image. An edge detection operator is then applied to the at least one scaled image to form at least one edge image. In addition, a threshold operator is applied to the at least one edge image to form at least one threshold image. A digital line drawing is then created based at least in part on the at least one threshold image.