Spatial variability under white light.

A: Captured image with compensated illumination. B: Control pattern applied to the captured image. C: Normalised image with white backlight. D: Normalised image with compensated light. E: Control pattern applied to the captured image (C). F: Comparison of the image histograms: the red one without applying any control and the blue one after applying the control. G: Comparison of profile lines, the red one without applying the control to (A) and the blue one after applying the control (A). The blue and red squares are the grey levels caused by a worm. H: Comparison of profile lines (C) and (D).