We exploit the prior on the joint histogram of irradiances at neighboring pixels to estimate the response function of specific camera models.

Here we show the estimated and ground truth inverse response functions of one channel for four camera models -- (a) Sony W1, (b) Canon G5, (c) Casio Z120, and (d) Minolta Z2. For these estimates we used 17,819, 9,529, 1,315, and 3,600 photographs, respectively. (a) also shows the initial guess used by our optimization.