Abstract: Provided herein are teachings directed to the creation of moiré-based auto-stereoscopic watermarks in rendered images. By choosing different halftone structures, which differ by having different spatial frequencies for each of two delineated partitions in an image, it becomes possible to embed arbitrary binary patterns into printed documents as digital watermarks. The invisible watermarks become moiré auto-stereoscopic images when the prints are viewed through an overlaid transparency “decoder” suitably prepared by virtue of being rendered with a uniform halftone structure having the correct special frequency in relationship with the partition frequencies employed in the printed document.

Abstract: What is provided is a system and method for node set construction and look-up table generation to transform image data in the form of color values of an input color image in an input color space to an output color space of an image output system. In the present method, node locations are selected based upon an importance value generated by a significance function which describes a relative importance of a given color value in the input image or a region thereof. A distance weighting function is also provided which is applied to the significance function to balance the significance of a given node against a relative positioning of all other nodes in the multi-dimensional grid. Nodes can be added or deleted according to methods also described herein. Accordingly, a multi-dimensional look-up table is generated wherein node tiling is based upon a significance of color values of an input image.