1. A method for image processing, comprising: receiving a depth image of a scene containing a human subject; receiving a color image of the scene containing the human subject; identifying a part of a body of the subject in at least one of the images; evaluating a quality of both the depth image and the color image, and selecting, responsively to the quality, one of the images to be dominant in processing of the part of the body in the images; and localizing the identified part in the dominant one of the images, while using supporting data from the other one of the images.