---
title: "PixelFormatConverter..::.PaletteAlphaThreshold Property "
canonical: https://www.graphicsmill.com/docs/gm5/P_Aurigma_GraphicsMill_Transforms_PixelFormatConverter_PaletteAlphaThreshold.htm
product: "Graphics Mill 5.5 for .NET"
---

This documentation is for the old version. [Go to the latest Graphics Mill docs](https://www.graphicsmill.com/docs/gm/)

# PixelFormatConverter.PaletteAlphaThreshold Property 
 
Gets/sets a value which specifies the alpha threshold.
 
**Namespace:** [Aurigma.GraphicsMill.Transforms](https://www.graphicsmill.com/docs/gm5/N_Aurigma_GraphicsMill_Transforms.htm.md)
 **Assembly:** Aurigma.GraphicsMill (in Aurigma.GraphicsMill.dll)
 
## Syntax
  
```
Public Property PaletteAlphaThreshold As Byte
```
 
```csharp
public byte PaletteAlphaThreshold { get; set; }
```
 
### Property Value
Threshold value.
 
## Remarks
  
When building a palette during color reduction for an image which should be saved to GIF, you need to have only one transparent color. However during color reduction you may get a number of colors with a different level of transparency. To avoid this, use this property. All alpha channel values which are greater or equal to this value will be changed to 255 (fully opaque), otherwise it will be 0.
 
**Note** 
If the [PaletteAlphaThresholdUsed](https://www.graphicsmill.com/docs/gm5/P_Aurigma_GraphicsMill_Transforms_PixelFormatConverter_PaletteAlphaThresholdUsed.htm.md) property is **false**, alpha threshold is not used, and therefore the palette may contain more than one transparent or semitransparent entry. Also, this value is disregarded if the [BuildAdaptivePaletteWithAlpha](https://www.graphicsmill.com/docs/gm5/P_Aurigma_GraphicsMill_Transforms_PixelFormatConverter_BuildAdaptivePaletteWithAlpha.htm.md) property is set to **false** (i.e. alpha channel is ignored during color reduction).
   
## See Also

### Reference

- [PixelFormatConverter Class](https://www.graphicsmill.com/docs/gm5/T_Aurigma_GraphicsMill_Transforms_PixelFormatConverter.htm.md)
- [Aurigma.GraphicsMill.Transforms Namespace](https://www.graphicsmill.com/docs/gm5/N_Aurigma_GraphicsMill_Transforms.htm.md)