better control over input image selection
review for https://github.com/openjournals/joss-reviews/issues/3603
PIVC currently reads images from a directory and performs analysis on pairs. As far as I understand the code, for e.g. a directory containing images a, b, c, d analysis would be done between images a & b, and c & d.
Choice of images used in the analysis should be left to the user for maximum flexibility.