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# vImage.Gamma

Describes either a used-defined or constant gamma.

```
enum Gamma
```

## Topics

### User Defined Gamma

[`case fullPrecision(Float)`](/documentation/Accelerate/vImage/Gamma/fullPrecision(_:))

A user-defined gamma value with full-precision calculation.

[`case halfPrecision(Float)`](/documentation/Accelerate/vImage/Gamma/halfPrecision(_:))

A user-defined gamma value with half-precision calculation.

### Constant Gamma

[`case bt709ForwardHalfPrecision`](/documentation/Accelerate/vImage/Gamma/bt709ForwardHalfPrecision)

ITU-R BT.709 standard.

[`case bt709ReverseHalfPrecision`](/documentation/Accelerate/vImage/Gamma/bt709ReverseHalfPrecision)

ITU-R BT.709 standard reverse.

[`case elevenOverFiveHalfPrecision`](/documentation/Accelerate/vImage/Gamma/elevenOverFiveHalfPrecision)

Half-precision calculation using a gamma value of `11/5` or `2.2`.

[`case elevenOverNineHalfPrecision`](/documentation/Accelerate/vImage/Gamma/elevenOverNineHalfPrecision)

Half-precision calculation using a gamma value of `11/9` or `(11/5)/(9/5)`.

[`case fiveOverElevenHalfPrecision`](/documentation/Accelerate/vImage/Gamma/fiveOverElevenHalfPrecision)

Half-precision calculation using a gamma value of `5/11` or `1/2.2`.

[`case fiveOverNineHalfPrecision`](/documentation/Accelerate/vImage/Gamma/fiveOverNineHalfPrecision)

Half-precision calculation using a gamma value of `5/9` or `1/1.8`.

[`case nineOverElevenHalfPrecision`](/documentation/Accelerate/vImage/Gamma/nineOverElevenHalfPrecision)

Half-precision calculation using a gamma value of `9/11` or `(9/5)/(11/5)`.

[`case nineOverFiveHalfPrecision`](/documentation/Accelerate/vImage/Gamma/nineOverFiveHalfPrecision)

Half-precision calculation using a gamma value of `9/5` or `1.8`.

[`case sRGBForwardHalfPrecision`](/documentation/Accelerate/vImage/Gamma/sRGBForwardHalfPrecision)

Half-precision calculation using the sRGB standard gamma value of `2.2`.

[`case sRGBReverseHalfPrecision`](/documentation/Accelerate/vImage/Gamma/sRGBReverseHalfPrecision)

Half-precision calculation using the sRGB standard gamma value of `1/2.2`.


---

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