Prediction of Despeckling Efficiency of DCT-Based Filters Applied to SAR Images

Abstract

This paper deals with one way to predict efficiency of despeckling for images acquired by a single-or multi-look synthetic aperture radar (SAR). A particular filter based on discrete cosine transform (DCT) and adapted to speckle characteristics is considered. Two quantitative criteria characterizing despeckling efficiency are analyzed. It is shown that even one parameter that can be calculated for image blocks sequentially or in parallel allows carrying out a rather accurate prediction. Moreover, such a prediction is possible for both spatially uncorrelated and correlated speckle.

Processing of Multichannel Remote-Sensing Images with Prediction of Performance Parameters

“…An obvious tendency is that mean P 0.5σ becomes larger and IPSNR increases for smaller number of looks. Other conclusions that can be drawn from analysis in a study in [57] are the following. Prediction is possible for filtering techniques with and without VST, where the prediction quality is better in the latter case.…”

“…They fit the curve well and have the arguments close to the maximal potential limit (0.38), where IPSNR attains very large values (approximately 10 dB and more). Additional studies concentrated on the multi-look SAR images that were corrupted by pure multiplicative noise [57]. Analysis has been done for speckle variance σ μ…”

“…Understanding that, in practice, noise can be spatially correlated [33], the case of spatially correlated noise -additive in [45] and multiplicative in [57] -are also studied. A difficulty of dealing with spatially correlated noise is that there are numerous shapes (and parameter sets) of 2D auto-correlation function or spatial spectrum of such a noise.…”

Despeckling of Multitemporal Sentinel SAR Images and Its Impact on Agricultural Area Classification

“…and I f kij ,i ¼ 1, …,I;j ¼ 1, …,J;k ¼ 1, …,K is the kth component image after despeckling or improvement of PSNR (IPSNR) equal to 10 log 10 σ 2 eq k =MSE out k [35,36]. Experiments carried out with 512Â512 pixel fragments of Sentinel SAR images have shown that IPSNR for Filter 1 varies within the limits from 5 to 12 dB, i.e., images enhance sufficiently.…”

Is Texture Denoising Efficiency Predictable?

“…Note, that IMSSIM less than 0.005 or IPSNR-HVS-M smaller than 0.5 dB practically cannot be considered as a visual quality improvement. 37 Secondly, it has been shown in Refs. 26 and 51 that IPSNR about 3 dB is not recognized as e±cient denoising if noise in original images is intensive.…”