1. An apparatus comprising: memory for storing: i) a luminance contrast sensitivity function (CSF1), ii) a chrominance contrast sensitivity function (CSF2), and iii) data representing color imagery; and one or more electronic processors configured for: predicting degradation of image areas associated with an application of digital watermarking in the data representing color imagery by applying the CSF1 and the CSF2 to the data representing color imagery, in which the CSF1 varies depending on luminance values associated with local regions of the data representing color imagery and in which the CSF1 is used for processing luminance data and the CSF2 is used for processing chrominance data; altering the data representing color imagery with digital watermarking, in which the digital watermarking is guided based on results obtained from the predicting including predicted degradation of image areas.