ImageValuePositions

ImageValuePositions[image,val] returns a list of pixel positions in image that exactly match the value val.

ImageValuePositions[image,val,d] returns all pixel positions that have values within a distance d from val.

Examples

Find positions of white pixels:

img = Image[{{0, 1}, {1, 0}}];
ImageValuePositions[img, 1]
(* {{1, 2}, {2, 1}} *)

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