---
title: detectsDarkOnLight
framework: vision
role: symbol
role_heading: Instance Property
path: vision/detectcontoursrequest/detectsdarkonlight
---

# detectsDarkOnLight

A Boolean value that indicates whether the request detects a dark object on a light background to aid in detection.

## Declaration

```swift
var detectsDarkOnLight: Bool
```

## Discussion

Discussion The default value is true.

## See Also

### Configuring a request

- [contrastAdjustment](vision/detectcontoursrequest/contrastadjustment.md)
- [contrastPivot](vision/detectcontoursrequest/contrastpivot.md)
- [maximumImageDimension](vision/detectcontoursrequest/maximumimagedimension.md)