# Corner Finder

Corner finder finds two edge lines around a corner and uses their intersection as the output point feature.

## Add

Corner Finder is available in Point Features Finder HMI control. The steps to add it are:

1. Select one image

2. Click "New" button under Finders panel

3. Choose "Corner Finder". After this, a corner finder will be available for user to edit

## Setting

The setting steps of a Corner Finder are very similar with those of a Line Finder. The only difference is that Corner Finder has two lines to find:

1. Align the two references lines to the two corner edges on image(s).

Click Refine Edges button to fine tune reference lines to real edges.

before refining edges | after refining edges

2. Adjust search length and projection length to find edges properly.

The two edge find tools share the same search length and projection length.

3. Choose polarity

Choose whether the edges are indicated by a dark to light transition, or light to dark transition, or any polarity along the arrow directions. The two edge find tools share the same polarity parameter, therefore the two arrow directions should be coordinated.

The following arrow directions will lead to an error unless “Any polarity” is chosen.

4. Adjust caliper number and ignore number

Number to ignore is the number of points that will be ignored in the fitting operation. Corner finder automatically filters out the given number of outliers that are farthest from fitting lines. Setting this number as non-zero value is important when pseudo edge points could impact line fitting results.

Number to ignore = 0 | Number to ignore = 2

## Run

After the settings, click "Ok" button, and then run the added corner finder to check the result following the steps shown below.