A Visual Enhancement Method of Schlieren Features Based on Correlation Frame Constraints

A technique of schlieren and sequence images, applied in the field of high-speed target schlieren detection, can solve the problem of low resolution of schlieren images, and achieve the effect of reducing the scale requirements

Active Publication Date: 2022-03-22
BEIJING INSTITUTE OF TECHNOLOGYGY
View PDF15 Cites 0 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The motion vector obtained by the cross-correlation method is only the maximum possible displacement in probability, and the calculated schlieren image has a low resolution

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
  • A Visual Enhancement Method of Schlieren Features Based on Correlation Frame Constraints
  • A Visual Enhancement Method of Schlieren Features Based on Correlation Frame Constraints
  • A Visual Enhancement Method of Schlieren Features Based on Correlation Frame Constraints

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0036] The method of the invention can realize real and quantitative measurement of the schlieren information of the airflow field in a large outdoor scene at low cost. This method relies on the CSBOS imaging system. In order to achieve high-precision quantitative analysis of the reconstructed schlieren sequence images and consider the relevance of moving images in the time dimension, a visual enhancement method for schlieren features based on associated frame constraints is proposed to solve the problem. The traditional optical flow method has the problem of low extraction accuracy of schlieren regions between multiple frames under the influence of noise, and improves the vector accuracy of schlieren in high dynamic motion sequence images.

[0037] The design concept of the present invention is as follows: firstly collect the schlieren moving image through the CSBOS schlieren system; RANSAC image registration; finally, in order to achieve high-precision quantitative analysis ...

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 relates to a schlieren feature visualization enhancement method based on associated frame constraints, which belongs to the field of high-speed target schlieren detection. The method collects high-dynamic schlieren sequence images through a background schlieren imaging system based on compression sampling, then uses Gaussian filtering to perform denoising preprocessing on the collected schlieren sequence images, and uses the KLT-RANSAC algorithm to perform image processing on the schlieren sequence images. Registration to obtain stable sequence images; finally, for the temporal correlation of high dynamic schlieren sequence images, the optical flow method is used to detect and output the motion vector of each pixel between two frames of images. The method is aimed at the problems of fast time-varying schlieren sequence images and the missing acquisition and indistinguishability of schlieren parameters caused by rich sharp and weak schlieren information, and considers the relevance of moving images in the time dimension to solve the problem of traditional optical flow methods. Under the influence of noise, the extraction accuracy of the schlieren area between multiple frames is low, and the vector accuracy of the schlieren in the high dynamic motion sequence image is improved.

Description

technical field [0001] The invention specifically relates to a schlieren feature visualization enhancement method based on associated frame constraints, and belongs to the field of high-speed target schlieren detection. Background technique [0002] Background Schlieren technology, that is, Background Oriented Schlieren, referred to as BOS, is a non-contact optical flow field measurement method combined with schlieren technology and digital image processing technology. Its principle is: the air is compressed due to the high-speed movement of the target. It will lead to changes in the refractive index, so the light will be deflected, and the gradient and density distribution of the flow field during the flight of the supersonic vehicle can be quantitatively calculated by analyzing the deflection of the light. BOS technology breaks through the limitations of traditional methods that can only be tested in wind tunnels. It can calculate the density, pressure, velocity, momentum,...

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 Patents(China)
IPC IPC(8): G06T7/269G06T7/33G06T7/35G06T5/00G06T5/20
CPCG06T7/269G06T7/33G06T7/35G06T5/002G06T5/20G06T2207/10016
Inventor 刘晗丁旭辉安建平卜祥元
Owner BEIJING INSTITUTE OF TECHNOLOGYGY
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