---
title: "Histogram..::.BuildSum Method (BitmapData, Boolean)"
canonical: https://www.graphicsmill.com/docs/gm5/M_Aurigma_GraphicsMill_Histogram_BuildSum_2_34083620.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/)

# Histogram.BuildSum Method (BitmapData, Boolean)
 
Builds the histogram for specified bitmap data. Histogram is based on average of pixel channels values (sum of these values divided at channels number). You can specify whether alpha channel should be included into this sum.
 
**Namespace:** [Aurigma.GraphicsMill](https://www.graphicsmill.com/docs/gm5/N_Aurigma_GraphicsMill.htm.md)
 **Assembly:** Aurigma.GraphicsMill (in Aurigma.GraphicsMill.dll)
 
## Syntax
  
```
Public Sub BuildSum ( _bitmapData As BitmapData, _useAlpha As Boolean _
)
```
 
```csharp
public void BuildSum(BitmapData bitmapData,bool useAlpha
)
```
 
### Parameters
 
 - bitmapData
     - Type: [Aurigma.GraphicsMill.BitmapData](https://www.graphicsmill.com/docs/gm5/T_Aurigma_GraphicsMill_BitmapData.htm.md)
 [BitmapData](https://www.graphicsmill.com/docs/gm5/T_Aurigma_GraphicsMill_BitmapData.htm.md) class instance to build the histogram for.

 - useAlpha
     - Type: [System.Boolean](http://msdn2.microsoft.com/en-us/a28wyd50)
If **true**, alpha channels is included (if available). Otherwise it is skipped. Typically alpha channel should be ignored when applying tone corrections.
   
## See Also

### Reference

- [Histogram Class](https://www.graphicsmill.com/docs/gm5/T_Aurigma_GraphicsMill_Histogram.htm.md)
- [BuildSum Overload](https://www.graphicsmill.com/docs/gm5/O_T_Aurigma_GraphicsMill_Histogram_BuildSum.htm.md)
- [Aurigma.GraphicsMill Namespace](https://www.graphicsmill.com/docs/gm5/N_Aurigma_GraphicsMill.htm.md)