Tool Universal Image Quality Index
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.
- Author: M.Ambrosi (c) 2017
- Menu: Imagery|Analysis
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 (optional output) | CORRELATION | The correlation coefficient. | - | |
| Luminance (*) | Grid (optional output) | LUMINANCE | The similarity of mean luminance. | - | |
| Contrast (*) | Grid (optional output) | CONTRAST | The similarity of contrast. | - | |
| Options | Grid system | Grid system | PARAMETERS_GRID_SYSTEM | - | - |
| k1 | Floating point | K1 | - | Minimum: 0.000000 Maximum: 1.000000 Default: 0.010000 | |
| k2 | Floating point | K2 | - | Minimum: 0.000000 Maximum: 1.000000 Default: 0.030000 | |
| L | Integer | L | The dynamic range for the image pixel, i.e. the number of different grey values. | Minimum: 0 Default: 255 | |
| Kernel Type | Choice | KERNEL_TYPE | The shape of the filter kernel. | Available Choices: [0] Square [1] Circle Default: 1 | |
| Kernel Radius | Integer | KERNEL_RADIUS | The kernel radius in cells. | Minimum: 0 Default: 2 | |
| (*) optional | |||||
Command-line
Usage: saga_cmd imagery_tools 13 [-GRID_A <str>] [-GRID_B <str>] [-QUALITY <str>] [-CORRELATION <str>] [-LUMINANCE <str>] [-CONTRAST <str>] [-K1 <double>] [-K2 <double>] [-L <num>] [-KERNEL_TYPE <str>] [-KERNEL_RADIUS <num>] -GRID_A:<str> First Grid Grid (input) -GRID_B:<str> Second Grid Grid (input) -QUALITY:<str> Universal Image Quality Index Grid (output) -CORRELATION:<str> Correlation Grid (optional output) -LUMINANCE:<str> Luminance Grid (optional output) -CONTRAST:<str> Contrast Grid (optional output) -K1:<double> k1 Floating point Minimum: 0.000000 Maximum: 1.000000 Default: 0.010000 -K2:<double> k2 Floating point Minimum: 0.000000 Maximum: 1.000000 Default: 0.030000 -L:<num> L Integer Minimum: 0 Default: 255 -KERNEL_TYPE:<str> Kernel Type Choice Available Choices: [0] Square [1] Circle Default: 1 -KERNEL_RADIUS:<num> Kernel Radius Integer Minimum: 0 Default: 2