To give back SSIM map (not just mean scalar value)
Sewar is a python package for image quality assessment using different metrics. You can check documentation here.
- Mean Squared Error (MSE)
- Root Mean Sqaured Error (RMSE)
- Peak Signal-to-Noise Ratio (PSNR) [1]
- Structural Similarity Index (SSIM) [1]
- Universal Quality Image Index (UQI) [2]
- Multi-scale Structural Similarity Index (MS-SSIM) [3]
- Erreur Relative Globale Adimensionnelle de Synthèse (ERGAS) [4]
- Spatial Correlation Coefficient (SCC) [5]
- Relative Average Spectral Error (RASE) [6]
- Spectral Angle Mapper (SAM) [7]
- Spectral Distortion Index (D_lambda) [8]
- Spatial Distortion Index (D_S) [8]
- Quality with No Reference (QNR) [8]
- Visual Information Fidelity (VIF) [9]
- Block Sensitive - Peak Signal-to-Noise Ratio (PSNR-B) [10]
- Add command-line support for No-reference metrics
Just as simple as
pip install sewar
a simple example to use UQI
>> > from full_ref import uqi
>> > uqi(img1, img2)
0.9586952304831419
sewar [metric] [GT path] [P path] (any extra parameters)
An example to use SSIM
foo@bar:~$ sewar ssim images/ground_truth.tif images/deformed.tif -ws 13
ssim : 0.8947009811410856
Available metrics list
mse, rmse, psnr, rmse_sw, uqi, ssim, ergas, scc, rase, sam, msssim, vifp, psnrb
Special thanks to @sachinpuranik99 and @sunwj.
[1] "Image quality assessment: from error visibility to structural similarity." 2004)
[2] "A universal image quality index." (2002)
[3] "Multiscale structural similarity for image quality assessment." (2003)
[4] "Quality of high resolution synthesised images: Is there a simple criterion?." (2000)
[5] "A wavelet transform method to merge Landsat TM and SPOT panchromatic data." (1998)
[6] "Fusion of multispectral and panchromatic images using improved IHS and PCA mergers based on wavelet decomposition." (2004)
[7] "Discrimination among semi-arid landscape endmembers using the spectral angle mapper (SAM) algorithm." (1992)
[8] "Multispectral and panchromatic data fusion assessment without reference." (2008)
[9] "Image information and visual quality." (2006)
[10] "Quality Assessment of Deblocked Images" (2011)