Universal Image Quality Index
- Author: M.Ambrosi (c) 2017
- Menu: Imagery | Analysis
Description
The Universal Image Quality Index compares two grids (greyscale images) using the three parameters luminance, contrast and structure. This is done for each pixel using a moving window as specified by the kernel radius. 
References
- Lasaponara, R. & Masini, N. (2012): Image Enhancement, Feature Extraction and Geospatial Analysis in an Archaeological Perspective. In: Lasaponara, R. & Masini, N. [Eds.]: Satellite Remote Sensing - A New Tool for Archaeology, S. 17-64. Springer Link.
- Wang, Z. & Bovik, A.C. (2002): A universal image quality index. IEEE Signal Processing Letters, vol.9, no.3, pp.81-84. IEEE-Xplore.
Parameters
|  | Name | Type | Identifier | Description | Constraints | 
|---|
| Input | First Grid | grid, input | GRID_A | - | - | 
| Second Grid | grid, input | GRID_B | - | - | 
| Output | Universal Image Quality Index | grid, output | QUALITY | The product of correlation, luminance and contrast similarity. | - | 
| Correlation | grid, output, optional | CORRELATION | The correlation coefficient. | - | 
| Luminance | grid, output, optional | LUMINANCE | The similarity of mean luminance. | - | 
| Contrast | grid, output, optional | CONTRAST | The similarity of contrast. | - | 
| Options | Grid System | grid system | PARAMETERS_GRID_SYSTEM | - | - | 
| k1 | floating point number | K1 | - | Minimum: 0.000000
Maximum: 1.000000
Default: 0.010000 | 
| k2 | floating point number | K2 | - | Minimum: 0.000000
Maximum: 1.000000
Default: 0.030000 | 
| L | integer number | L | The dynamic range for the image pixel, i.e. the number of different grey values. | Minimum: 1
Default: 255 | 
| Kernel Type | choice | KERNEL_TYPE | The kernel's shape. | Available Choices:
[0] Square
[1] Circle
Default: 1 | 
| Radius | integer number | KERNEL_RADIUS | cells | Minimum: 0
Default: 2 | 
Command Line
Usage: saga_cmd imagery_tools 13 [-GRID_A ] [-GRID_B ] [-QUALITY ] [-CORRELATION ] [-LUMINANCE ] [-CONTRAST ] [-K1 ] [-K2 ] [-L ] [-KERNEL_TYPE ] [-KERNEL_RADIUS ]
  -GRID_A:       	First Grid
	grid, input
  -GRID_B:       	Second Grid
	grid, input
  -QUALITY:      	Universal Image Quality Index
	grid, output
  -CORRELATION:  	Correlation
	grid, output, optional
  -LUMINANCE:    	Luminance
	grid, output, optional
  -CONTRAST:     	Contrast
	grid, output, optional
  -K1:        	k1
	floating point number
	Minimum: 0.000000
	Maximum: 1.000000
	Default: 0.010000
  -K2:        	k2
	floating point number
	Minimum: 0.000000
	Maximum: 1.000000
	Default: 0.030000
  -L:            	L
	integer number
	Minimum: 1
	Default: 255
  -KERNEL_TYPE:  	Kernel Type
	choice
	Available Choices:
	[0] Square
	[1] Circle
	Default: 1
  -KERNEL_RADIUS:	Radius
	integer number
	Minimum: 0
	Default: 2