Measure an angle in an image

Use a Measure Angle block to measure the angle of the object from a horizontal or vertical axis.

To measure the angle of an object in an image

1. On the Block Definitions toolbar, select Measurement.

   The Measurement list expands.

2. Drag a Measure Angle block onto the Canvas.

   

3. Connect the block to other blocks on the Canvas as needed.

4. Select the Measure Angle block on the Canvas.

5. Right-click the block, and then select Properties.

   

   The Properties side sheet appears on the right side of the screen.

   

6. Optional: Select the expand button () to expand the Reference angle coordinates area.

   This enlarges the images so that you can more easily define the ROI.

   You can select the collapse button () to return to the previous menu.

7. Optional: On the enlarged image, use the zoom tools to zoom in () and out () of the image.

8. Select the image twice to create the connection points for the reference angle axis at that position.

   The Measure Angle block always measures the acute angle between the detected edge and the reference angle axis.

9. Optional: Select Clear to delete the defined reference angle and start over.

10. In the Edge-detection threshold value box, enter the threshold for detecting edges in the image.

    You can set this value between 0 and 255. Values closer to 255 detect only the most well-defined edges. Values closer to 0 detect many edges and may introduce noise.

    You can also use the slider or the increase button () and decrease button () on the same row to change the value.

11. In the Minimum length of lines detected box, enter the minimum length that the detected edge must be for the software to calculate the angle.

    You can set this value to any integer greater than or equal to zero.

    You can also use the increase button () and decrease button () on the same row to change the value.

12. Select Apply Changes.

    The preview image for the block updates on both the Properties side sheet and the Canvas.