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# GLKTextureLoaderGrayscaleAsAlpha

Whether or not to treat greyscale image data as alpha information.

```
let GLKTextureLoaderGrayscaleAsAlpha: String
```

## Discussion

This key specifies whether the image data in a grayscale image should be treated as alpha information. The value for this key is an <doc://com.apple.documentation/documentation/Foundation/NSNumber> object that specifies a boolean value. If <doc://com.apple.documentation/documentation/Swift/false>, the image data is treated as luminance data. If <doc://com.apple.documentation/documentation/Swift/true>, the image data is treated as alpha data. The default value is <doc://com.apple.documentation/documentation/Swift/false>. This key is ignored if the source image is not a grayscale image.

---

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