it works! even for small differences like changes in color or shading in certain areas like the line beneath the light blue circle on the upper right. Abusive comment hidden. (Show it anyway.)
What is the yellow line? Is it added by computer for study purposes or Is it something that they can follow with their hands or by touch? Even though they have gloves on, they can still touch their noses to the ground.... Abusive comment hidden. (Show it anyway.)