Real-time time-domain denoising method for 3D range images based on photon counting

Abstract

The invention discloses a three-dimensional distance image time domain real-time denoising method based on photon counting. The method comprises the steps of firstly improving a traditional imaging model based on a maximum likelihood estimation algorithm by using different characteristics of flight time of noise photons and signal photons; then using the prior knowledge to act as a discriminating standard for judging the signal photons and the noise photons, carrying out sequential detection on photons detected by a detector subsequently, and updating the standard in real time by using flight time of discriminated signal photons detected subsequently at the same time; and finally, using the detected signal photon number K to act as a sampling stopping threshold condition for each pixel point, deciding optimum distance information of each pixel point adaptively, and reconstructing a three-dimensional distance image with a target being clear. The method disclosed by the invention not only can restrain influences of intrinsic Poisson noises in the photon counting process, but also avoids a process of generating a photon counting histogram required by the traditional imaging model based on a maximum likelihood estimation algorithm, and reduces the imaging time.

Description

technical field [0001] The invention is applicable to a photon counting three-dimensional imaging laser radar system, in particular to a photon counting-based time-domain real-time denoising method for a three-dimensional range image. Background technique [0002] The distance image uses a three-dimensional image mode to describe the target area of ​​interest. Its data cube contains the geometric invariant characteristics of the target, which can avoid distortion and confusion in the two-dimensional image. It is widely used in machine vision, industrial mold design and military targets. Automatic identification and tracking and other fields. At present, several technical approaches are known for obtaining range images of targets. Among them, the photon counting three-dimensional imaging lidar system using Gm-APD working in photon counting mode as its laser echo signal photon detector is to achieve high time resolution measurement of targets in photon flight mode. [0003] ...

AI Technical Summary

Problems solved by technology

Both of these two technical approaches require more complex follow-up algorithm processing, and are not suitable for real-time applications; among them, the second method is prone to smoothing in the low reflectivity area of ​​the target scene, especially in the edge details

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