Application of optimized 2D S-transform in digital speckle interferometry phase pattern denoising

To address the problem of a large amount of noise in the phase pattern in digital speckle pattern interferometry, which seriously affects the phase reconstruction and measurement precision, a filtering method based on optimized 2D S-transform is proposed in this paper. The optimized 2D S-transform provides high signal-to -noise ratio denoising method by adding tilt factors and translation factors to keep the Gaussian window of the appropriate size at different frequency positions. The analysis results of different frequency fringe pattern denoising show that the criteria metrics indicator signal-to-noise ratio (SNR) of the results of the proposed method can reach at least 14.5435 dB and the criteria metrics peak signal-to-noise ratio (PSNR) can reach at least 19.4555 dB, which has better precision compared with the traditional method and solves the incongruity between the smoothness of low-density fringe and the integrity of high-density fringe.