Context model and dual-tree complex wavelet transform-based denoising method for underwater sonar image

A dual-tree complex wavelet and underwater sonar technology, applied in the field of image processing, can solve the problems of image detail information loss and non-optimum

Inactive Publication Date: 2013-01-30
HARBIN ENG UNIV
View PDF1 Cites 6 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The commonly used method in the transform domain method is the wavelet-based shrinkage threshold method. The traditional global threshold is not optimal for each transform coefficient, resulting in the loss of image detail information.

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • Context model and dual-tree complex wavelet transform-based denoising method for underwater sonar image
  • Context model and dual-tree complex wavelet transform-based denoising method for underwater sonar image
  • Context model and dual-tree complex wavelet transform-based denoising method for underwater sonar image

Examples

Experimental program
Comparison scheme
Effect test

Embodiment Construction

[0063] The present invention is described in more detail below in conjunction with accompanying drawing example:

[0064] combine Figure 1~6 , the size of the selected underwater sonar image is 256×256, using wavelet hard threshold, wavelet soft threshold, dual-tree complex wavelet soft threshold and the present invention to denoise images containing the same noise. And the peak signal-to-noise ratio (PSNR) is used as the evaluation index to measure the denoising effect. figure 1 Shown is a schematic flow sheet of the present invention, and the specific implementation steps of the present invention are as follows:

[0065] 1. Perform dual-tree complex wavelet decomposition on the selected underwater sonar image, and the number of decomposition layers is four.

[0066] figure 2 What is shown is the structural diagram of a one-dimensional dual-tree complex wavelet transform analysis filter bank. Tree A and tree B in the figure represent the real part and imaginary part of ...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

PUM

No PUM Login to view more

Abstract

The invention aims at providing a Context model and dual-tree complex wavelet transform-based denoising method for an underwater sonar image, comprising the step of: performing dual-tree complex wavelet decomposition on the underwater sonar image, wherein the low-frequency approximate component obtained by conducting the four-layer dual-tree complex wavelet decomposition on the image keeps invariable; performing denoising processing on the high-frequency component of the image; and performing dual-tree complex wavelet inverse transform on the processed complex wavelet coefficients so as to obtain the final image subjected to denoising. According to the denoising method, the similarity of energies among the dual-tree complex wavelet coefficients is measured by adopting the Context model, the coefficients with the similar energies are classified, different thresholds are determined aiming at each class of the coefficients, and denoising is realized by combining with a soft-threshold function. Threshold section is optimized; and more image details are reserved while the noise is removed, so that the phenomenon that the coefficients are excessively killed is suppressed.

Description

technical field [0001] The invention relates to a denoising method in the technical field of image processing. Background technique [0002] During the process of image acquisition and transmission, it is often disturbed by the external environment, resulting in image quality degradation, which seriously affects the subsequent image processing work. Therefore, image denoising preprocessing has also become a research hotspot in image processing, which provides a better research basis for subsequent high-level image processing. [0003] There are many types of image denoising methods, which are mainly divided into spatial domain methods and transform domain methods. The spatial domain method is to directly calculate the gray value of the image. The commonly used methods are: median filter, mean filter, non-local mean filter and so on. Both the median filter and the mean filter have a certain degree of edge blurring, and the non-local mean filter requires a large amount of ca...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

Application Information

Patent Timeline
no application Login to view more
Patent Type & Authority Applications(China)
IPC IPC(8): G06T5/00
Inventor 李一兵张静叶方汤春瑞付强李一晨李骜田雪怡
Owner HARBIN ENG UNIV
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Try Eureka
PatSnap group products

Browse by: Latest US Patents, China's latest patents, Technical Efficacy Thesaurus, Application Domain, Technology Topic.

© 2024 PatSnap. All rights reserved.Legal|Privacy policy|Modern Slavery Act Transparency Statement|Sitemap