### OCV Tool Parameters

OCV Tool parameters include controls for Defect Detection, Filtering, and Settings.

##### Defect Detection

Click the Defect Detection area of the OCV Tool parameters to display controls for Tolerance and Units (Percentage of total symbol size, or an absolute value in Pixels). You can also determine whether the tool bases defects on Total Residue Area or Largest Blob, or set it to Check Minimum Contrast, which rejects any symbol whose contrast falls below 50% of the trained symbol’s contrast.

- Total Residue Area: Judges whether the total area of the difference image is within the set judgment value.

- Tolerance of Total Residue Area: Sets the judgment value of the area of the difference image. (Range: 0-100% or 0-10000000 pixels)

- Largest Blob: Determines whether the area of the maximum blob in the difference image is within the set tolerance.

- Tolerance of Largest Blob: Sets the judgment value for the maximum blob area of the difference image. (Range: 0-100% or 0-10000000 pixels)

- Check Minimum Contrast: Symbols with a symbol contrast less than 50% of the trained symbol contrast are considered defective.

- Unit: Set the unit of tolerance when judging the above total difference area and maximum blob area.
  [Percentage]: Judgment is made as a relative value (percentage) when the area of the symbol during training is set to 100%.
  [Pixels]: Judgment is made based on the area value in pixels.

##### Filtering

Click the Filtering area of the OCV Tool parameters to display controls for Minimum Symbol Size and Residue Cleanup.

- Minimum Symbol Size: Allows you to set the minimum number of pixels required for a blob to constitute a symbol.

- Residue Cleanup: Allows you to set the number of pixels to remove around the perimeter of each blob of residue. Increase this value if the size of symbols varies by a large amount.

##### Settings

Click the Settings area of the OCV Tool parameters to display controls for Polarity, Single Symbol, and AutoFind the Symbols.

- Polarity: The OCV Tool can usually detect polarity on its own, but when it can’t, set Polarity directly to Light on Dark or Dark on Light.

- Single Symbol: Train all features within the template ROI as one symbol.

- AutoFind the Symbols: Search automatically for trained symbols. Disable AutoFind to save processing time if you are already using a Locate Tool.