User`s guide

7 Analysis and Enhancement
The Video Viewer2 window displays the ROI that has been annotated with
two white lines.
The Display block shows a value of 54, which is the angle in degrees
between the two lines on the annotated ROI.
You have now annotated an image with two lines and measured the angle
between them. For additional information, see the Ho ugh T ransform, Find
Local Maxima, Hough Lines, and Draw Shapes block reference pages in the
Video and Image Processing Blockset Reference.
7-26