1. A method for characterizing a response function of an output device, the method comprising the steps of: (a) producing a test image on the output device with a set of one or more test patches having known code values; (b) obtaining one or more captured images of the test image using a digital camera; (c) determining colorimetric values for the test patches in the captured images using a known response function of the digital camera, wherein the known response function of the digital camera relates code values of the captured image to corresponding colorimetric values of the test image; (d) determining a response function of the output device which relates the known code values to the determined colorimetric values throughout the entire range of colors of the output device.