# colorThreshold(_:destination:) Creates a binary image from a 32-bit pixel buffer. ``` func colorThreshold(_ threshold: Float, destination: vImage.PixelBuffer) ``` ## Parameters `threshold` The threshold value. `destination` The destination pixel buffer. ## Discussion This function generates an image with source values that are less than `threshold` set to `0`, and source values that are greater than `threshold` set to `1`. Use this function to binarize an image. For example, the following code applies a threshold of `0.5` to a pixel buffer. The source values `0.0`, `0.2`, and `0.4` are less than the threshold and the function returns `0.0` for the first three elements. The source values `0.6`, `0.8`, and `1.0` are greater than the threshold and the function returns `1.0` for the last three elements. ```swift let buffer = vImage.PixelBuffer( pixelValues: [0.0, 0.2, 0.4, 0.6, 0.8, 1.0], size: vImage.Size(width: 6, height: 1)) buffer.colorThreshold(0.5, destination: buffer) // Prints "[0.0, 0.0, 0.0, 1.0, 1.0, 1.0]". print(buffer.array) ``` --- Copyright © 2026 Apple Inc. All rights reserved. | [Terms of Use](https://www.apple.com/legal/internet-services/terms/site.html) | [Privacy Policy](https://www.apple.com/privacy/privacy-policy)