Histogram Matching
- Author: O.Conrad (c) 2019
- Menu: Grid | Calculus | Transformations
Description
This tool alters the values of a grid so that its value distribution (its histogram), matches that of a reference grid. The first method simply uses arithmetic mean and standard deviation for adjustment, which usually is sufficient for normal distributed values. The second method performs a more precise adjustment based on the grids' histograms. 
Parameters
|  | Name | Type | Identifier | Description | Constraints | 
|---|
| Input | Grid | grid, input | GRID | - | - | 
| Reference Grid | grid, input | REFERENCE | - | - | 
| Output | Adjusted Grid | grid, output, optional | MATCHED | - | - | 
| Options | Grid System | grid system | PARAMETERS_GRID_SYSTEM | - | - | 
| Grid system | grid system | REFERENCE_GRIDSYSTEM | - | - | 
| Method | choice | METHOD | - | Available Choices:
[0] standard deviation
[1] histogram
Default: 1 | 
| Histogramm Classes | integer number | NCLASSES | Number of histogram classes for internal use. | Minimum: 100
Default: 10 | 
| Maximum Sample Size | integer number | MAXSAMPLES | If set to zero all data will be used to build the histograms. | Minimum: 0
Default: 1000000 | 
Command Line
Usage: saga_cmd grid_calculus 21 [-GRID ] [-MATCHED ] [-REFERENCE ] [-METHOD ] [-NCLASSES ] [-MAXSAMPLES ]
  -GRID:      	Grid
	grid, input
  -MATCHED:   	Adjusted Grid
	grid, output, optional
  -REFERENCE: 	Reference Grid
	grid, input
  -METHOD:    	Method
	choice
	Available Choices:
	[0] standard deviation
	[1] histogram
	Default: 1
  -NCLASSES:  	Histogramm Classes
	integer number
	Minimum: 100
	Default: 10
  -MAXSAMPLES:	Maximum Sample Size
	integer number
	Minimum: 0
	Default: 1000000