The present disclosure relates generally digital watermarking and data hiding techniques. One claim recites a method comprising: obtaining data representing imagery; using one or more configured processors, transforming the data into a multi-channel color space; obtaining information indicating an impact of adding a color channel encoded signal to a color direction of the data; determining a color space direction for encoded signal detection; obtaining weighting factors based on the information indicating an impact of adding a color channel encoded signal; weighting the color channel encoded signal with weighting factors to yield a modified color channel encoded signal; using one or more configured processors, embedding the modified color channel encoded signal in the data representing imagery. Of course, other claims and combinations are provided as well.