Figure 9 An example of image registration. (a) Image taken at time 0 (2-4  h after setup) clearly showing precipitant. (b) Drop after one week; four crystals are apparent in the precipitant. (c) Images (a) and (b) registered, maximizing correlation coefficient to 75%, subtracted and scaled using a local scaling algorithm with a box size of 15 pixels. (d) Edges detected using image (b). (e) Edges detected using image (c), showing the increase in the signal to noise after image subtraction takes place.

© International Union of Crystallography 2002