DiffImagesResult

diffImages returns this rather than a DiffImageResult: a list has no before and after, and the mask says which of them disagree rather than what happened to a pixel.

Field	What it is
width	How wide the frame all of them were compared in is.
height	How tall it is.
areas	Where each picture sits in it, in the order they were given.
offsets	How far each was moved to line it up with the baseline.
baseline	Which of them the rest were counted against.
mask	A bit a picture: bit i is set where the picture at i differs from the baseline.
regions	Where the changes are, in reading order.
stats	A DiffImagesStats.
complete	Whether the list of regions holds all of them.

DiffImagesStats is pixels, covered, unchanged, changed and ratio as a pair's is, with apart saying how many pixels each picture disagrees with the baseline about.

DiffImagesSimilarity, which imagesSimilarity returns, is the same counts as shares.