---
title: "TiffReader..::.FirstExtraChannelIsAlpha Property "
canonical: https://www.graphicsmill.com/docs/gm5/P_Aurigma_GraphicsMill_Codecs_TiffReader_FirstExtraChannelIsAlpha.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/)

# TiffReader.FirstExtraChannelIsAlpha Property 
 
Gets/sets a value indicating whether the reader should interpret the first extra channel as alpha channel in pixel data.
 
**Namespace:** [Aurigma.GraphicsMill.Codecs](https://www.graphicsmill.com/docs/gm5/N_Aurigma_GraphicsMill_Codecs.htm.md)
 **Assembly:** Aurigma.GraphicsMill (in Aurigma.GraphicsMill.dll)
 
## Syntax
  
```
Public Property FirstExtraChannelIsAlpha As Boolean
```
 
```csharp
public bool FirstExtraChannelIsAlpha { get; set; }
```
 
### Property Value
 **true** if the reader interprets the first extra channel as alpha; otherwise, **false**.
 
## Remarks
  
For example, assume you read an image contained three color channels (RGB) and two extra ones. If this property is **true**, the image loaded from frame using [Frame.GetBitmap(Bitmap)](https://www.graphicsmill.com/docs/gm5/M_Aurigma_GraphicsMill_Codecs_Frame_GetBitmap_1_fd4033ef.htm.md) method will be interpreted as ARGB (RGB + alpha). [TiffFrame.ExtraChannels](https://www.graphicsmill.com/docs/gm5/P_Aurigma_GraphicsMill_Codecs_TiffFrame_ExtraChannels.htm.md) collection will contain one extra channel in this case. Otherwise, if the FirstExtraChannelIsAlpha property is **false**, it will be interpreted as RGB with two extra channels.
 
Default value is **true**.
   
## See Also

### Reference

- [TiffReader Class](https://www.graphicsmill.com/docs/gm5/T_Aurigma_GraphicsMill_Codecs_TiffReader.htm.md)
- [Aurigma.GraphicsMill.Codecs Namespace](https://www.graphicsmill.com/docs/gm5/N_Aurigma_GraphicsMill_Codecs.htm.md)

### Manual

- [Working with TIFF Extra Channels](https://www.graphicsmill.com/docs/gm5/WorkingwithTIFFExtraChannels.htm.md)