The Region of Interest (ROI) is a polygon that bounds the area of the original image containing a single friction ridge impression, separating it from the background and any other friction ridge data present in the image. Using an ROI is strongly recommended when the overall image contains multiple impressions or when differentiating between the friction ridge detail and the background is difficult.

There can be only one ROI for a given image. All other features marked must be within the ROI, with the exception of the Center point of reference/CPR.

An ROI includes only one impression made by a single or contiguous portion of friction ridge skin.

Simultaneous impressions or other images containing multiple impressions must mark each impression on a separate duplicate of the image. In the case of overlapping friction ridge impressions, the ROI may include the area where impressions are superimposed.

Click down at any point around the region of interest's border, and drag around that area to lasso the region of interest. Clicking in the canvas again, or clicking on the Delete button, will clear the previous outline. Choose Check My Answer on the bottom left to compare your solution to an example of expert markup.