Laser differential imaging detection method and device thereof

Abstract

The invention discloses a laser difference imaging detection method and a device for the same. The method comprises the following steps: performing range-gated imaging to obtain n frames of retroreflected images of n slices of a region to be detected in a one-frame one-pulse one-gate exposure manner; dividing the n frames of retroreflected images into m information frames and n-m background frames according to a grayscale threshold value; calculating differences of the m information frames and the background frames to obtain m enhanced information frames of the m information frames, and dividing the m enhanced information frames into k bubble information frames and m-k pseudo information frames by adopting a trained classifier; calculating a grayscale mean value and modulation time delays of the k bubble information frames respectively, and performing fitting to obtain a spatial distribution curve of bubbles along with the time delay; obtaining a range of a bubble region and yield of the bubbles according to the spatial distribution curve, wherein m, n and k are all natural numbers not smaller than 1. According to the method and the device, the range and the yield of the bubble region can be accurately detected, and the method and the device have the characteristics of high accuracy, high adaptability and high flexibility, and is significant for underwater bubble detection and analysis.

Description

technical field [0001] The invention belongs to the technical field of underwater optical imaging, and more specifically relates to a laser differential imaging detection method and a device thereof. Background technique [0002] High-precision, rapid and quantitative detection of underwater bubbles is of great significance in ship wake detection and submarine cold seep detection. Taking cold seep detection as an example, cold seep is a water-gas mixture of seabed water, hydrocarbons, and hydrogen sulfide, which has an important impact on the global carbon cycle and climate warming, and natural gas stored in hydrates is future energy, so cold seep Detection has important research significance for studying the impact of cold seep gas on global warming and guiding the exploration and development of marine water and gas resources. [0003] Underwater bubbles have different physical effects such as sound and light, and these effects can be used to detect bubbles. Non-imaging o...

AI Technical Summary

Problems solved by technology

Non-imaging optical wake bubble detection is one of the methods of bubble detection. According to the relationship between the light intensity reflected by the bubble at a certain angle and the density of the bubble, the spatial distribution of the bubble is inversely deduced, but the backscattering intensity of the bubble is related to the diameter and density of the bubble. The distribution relationship is complex, which has become a difficult problem in optical wake detection. At present, the spatial distribution of bubbles can only be qualitatively judged by the intensity of retroreflected light, and the spatial distribution and generation of bubbles cannot be accurately detected.

Underwater optical imaging bubble detection uses high-speed photography technology and image processing technology to study the movement and distribution of bubbles, but the resolution of underwater optical imaging is seriously affected by seawater backscattering. Image processing technology is difficult to analyze bubbles, which does not meet the needs of high-precision and quantitative detection

Multi-beam scanning sonar observation method, as an acoustic bubble detection method, can effectively observe the three-dimensional dynamic distribution of bubbles in a certain sea area, but the resolution is low. Although the presence or absence of bubbles can be judged, it is difficult to conduct high-precision detection of the amount and spatial distribution of bubbles

[0004] In summary, there is currently a lack of effective methods for high-precision quantitative detection of bubbles

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