Opto-acoustic image reconstruction prefilter based on Renyi entropy

Abstract

The invention belongs to the signal processing field, and specifically relates to clutter filtering on opto-acoustic signals through Renyi entropy so as to improve signal to noise ratio and opto-acoustic imaging quality of the opto-acoustic signals. The opto-acoustic image reconstruction prefilter based on Renyi entropy includes the following steps: 1) acquiring opto-acoustic signals; 2) performing time frequency distribution solution on the opto-acoustic signals; 3) performing Renyi entropy solution on each opto-acoustic signal point; 4) determining the threshold; 5) performing filtering processing; and 6) performing image reconstruction on the opto-acoustic signals which are processed through filtering. Compared with the prior art, the opto-acoustic image reconstruction prefilter based on Renyi entropy has the following advantages: 1) the signal to noise ratio of the reconstructed image is obviously improved when opto-acoustic image reconstruction is performed through the opto-acoustic signals which are processed by the prefilter; and 2) the mean square error of the reconstructed image is obviously reduced when opto-acoustic image reconstruction is performed through the opto-acoustic signals which are processed by the prefilter.

Description

technical field [0001] The invention belongs to the field of signal processing, and in particular relates to performing clutter filtering on photoacoustic signals by using Renyi entropy, thereby improving the signal-to-noise ratio and photoacoustic imaging quality of photoacoustic signals. Background technique [0002] In the process of photoacoustic image reconstruction, there are many factors that affect the imaging quality, and the two most important factors are the signal-to-noise ratio of the original photoacoustic signal and the image reconstruction algorithm. However, the current research on photoacoustic image reconstruction is more biased towards the continuous optimization and improvement of the algorithm, but ignores the influence of the quality of the photoacoustic signal itself. The photoacoustic signal is obtained from an ultrasound transducer, which is activated at the same time as the laser pulse is generated. Theoretically, the photoacoustic signal received...

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Problems solved by technology

For example, the filter back projection reconstruction algorithm proposed by Zeng Yaguang of South China Normal University in 2005 can properly improve the intensity and signal-to-noise ratio of the reconstructed photoacoustic signal, but it will also bring about image artifacts; Song Zhiyuan of Tianjin University In 2008, proposed to restore the photoacoustic signal by using the regularization method. This algorithm provides an effective way to reproduce the light absorption distribution structure inside the tissue better and more accurately, but the regularization parameter is generally noise. function, in the case of unknown noise, the process of photoacoustic signal restoration has great subjectivity; Northeastern University Xiao Qian et al. proposed to use the modulus maximum method to filter the clutter in the photoacoustic signal in 2011. The information of discontinuities can be well preserved, but the output signal-to-noise ratio is greatly affected by the algorithm decomposition scale

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