Detecting conflicts between multiple different encoded signals within imagery, using only a subset of available image data

Abstract

This disclosure relates to advanced signal processing technology including steganographic embedding and digital watermarking. One combination disclosed in the description includes an apparatus comprising: memory storing an image comprising a plurality of color channels; means for locating image areas including an encoded signal with each color channel of the plurality of color channels, said means for locating identifying a plurality of image areas; means for generating one or more detectability measures corresponding to the encoded signal for each of the plurality of image areas; means for determining whether the encoded signal can be decoded from the plurality of image areas to obtain a plural-bit message component carried therein; means for selecting, per color channel, only one (1) image area as a validation point based on one or more generated detectability measures for that color channel, and based on whether the one (1) image area includes a decodable plural-bit message component; and means for generating information associated with a spatial location of each of the validation points in the image. Of course, other technology, features and combinations are described as well.