Figure 8.

Gamma correction to correct for shadows around droplets. The droplet (a) is filtered with a low-pass filter, resulting in a blurred image as shown in (b). The normalized values of the low-pass filtered image are then used as γ values, resulting in the corrected image in (c). (d) and (e) show more examples of droplets before (left) and after (right) gamma correction. Shadow pixels along the edges of the droplet have been ‘boosted’, while the centre details remain relatively similar. Droplets with no dark edges should have no changes.