Signal detection adaptable to accommodate various lighting conditions, and to embedding signals according to anticipated lighting conditions likely to be present during image capture. One claim recites a method comprising: obtaining data representing picture elements of imagery or video, the imagery or video having been captured with a camera; obtaining lighting information associated with image capture of the imagery or video; based on the lighting information, adapting a detection process, in which the detection process is adapted by applying different weightings to different color channels for detection, the different weightings being associated with the lighting information; using a programmed electronic processor, analyzing the data to determine whether auxiliary data is encoded therein, said act of analyzing utilizes the adapted detection process. Of course, different combinations and claims are provided too.