```{index} single: Filters; ITK Otsu Multiple Thresholds Image Filter
```
# ITK Otsu Multiple Thresholds Image Filter

Threshold an image using multiple Otsu Thresholds.

## Group (Subgroup)

ITKThresholding (Thresholding)

## Description

This filter creates a labeled image that separates the input image into various classes. The filter computes the thresholds using the OtsuMultipleThresholdsCalculator and applies those thresholds to the input image using the ThresholdLabelerImageFilter . The NumberOfHistogramBins and NumberOfThresholds can be set for the Calculator. The LabelOffset can be set for the ThresholdLabelerImageFilter .

This filter also includes an option to use the valley emphasis algorithm from H.F. Ng, "Automatic thresholding for defect detection", Pattern Recognition Letters, (27): 1644-1649, 2006. The valley emphasis algorithm is particularly effective when the object to be thresholded is small. See the following tests for examples: itkOtsuMultipleThresholdsImageFilterTest3 and itkOtsuMultipleThresholdsImageFilterTest4 To use this algorithm, simple call the setter: SetValleyEmphasis(true) It is turned off by default.* ScalarImageToHistogramGenerator

- OtsuMultipleThresholdsCalculator
- ThresholdLabelerImageFilter

![](Images/ITKOtsuThreshold.png)


### Input Parameter(s)

| Parameter Name | Parameter Type | Parameter Notes | Description |
|----------------|----------------|-----------------|-------------|
| Number Of Thresholds | UInt8 |  | Set/Get the number of thresholds. Default is 1. |
| Label Offset | UInt8 |  | Set/Get the offset which labels have to start from. Default is 0. |
| Number Of Histogram Bins | Scalar Value |UInt32 | Set/Get the number of histogram bins. Default is 128. |
| Valley Emphasis | Bool |  | Set/Get the use of valley emphasis. Default is false. |
| ReturnBinMidpoint | Bool |  | Should the threshold value be mid-point of the bin or the maximum? Default is to return bin maximum. |

### Input Cell Data

| Parameter Name | Parameter Type | Parameter Notes | Description |
|----------------|----------------|-----------------|-------------|
| Image Geometry | Geometry Selection | Image | Select the Image Geometry Group from the DataStructure. |
| Input Cell Data | Array Selection | Allowed Types: int8, uint8, int16, uint16, int32, uint32, int64, uint64, float32, float64 | The image data that will be processed by this filter. |

### Output Cell Data

| Parameter Name | Parameter Type | Parameter Notes | Description |
|----------------|----------------|-----------------|-------------|
| Output Cell Data | DataObjectName |  | The result of the processing will be stored in this Data Array inside the same group as the input data. |

## Example Pipelines

## License & Copyright

Please see the description file distributed with this plugin.

## DREAM3D-NX Help

If you need help, need to file a bug report or want to request a new feature, please head over to the [DREAM3DNX-Issues](https://github.com/BlueQuartzSoftware/DREAM3DNX-Issues/discussions) GitHub site where the community of DREAM3D-NX users can help answer your questions.