Hi xrafoo,

Perimeter and Area are the same information than Contour and Interior but the laters are expressed in pixel while the firsts are given in real units computed from the pixel size information (that you can edit if not properly set) from your image.

It’s possible to observe a small difference between these measures Contour and Interior while really be computed on a binary mask (made from the ROI) while Perimeter and Area will try to use the original ROI geometry if possible.

Best,

– Stephane