Contrast Threshold
Specify the threshold for how much contrast (difference between light and dark) is required in the image to identify something as an edge. Input the value or change the value using buttons.

Set a value between 1 and 200. The default value is 50. If you set a small value, the tool will be able to find the target in obscure images as well but take longer to complete the location process. If the tool is prone to inadequately find blemishes and other unwanted edges with low contrast, try setting a larger value. Those image features whose contrast is lower than the threshold are ignored. Selecting the [Image + Edges] in [Image Display Mode] lets you check the image features extracted based on the current threshold.