Automatic focusing method and system based on flight time

Abstract

The invention relates to the technical field of imaging systems, in particular to an automatic focusing method and system based on flight time, and the method comprises the following steps: measuringan object distance u between a laser ranging module and a target object, and transmitting object distance data to an image acquisition card; enabling the image acquisition card to estimate an initialfocal length f of the lens through interpolation operation by taking an object distance u as a setting basis; enabling the image acquisition card to set a focusing search range and a focusing motor motion step number according to a focal length f, obtain a plurality of images in the focusing search range, compare the obtained images to obtain a maximum characteristic value, and record an adjustment value of the focusing motor when the maximum characteristic value is obtained; and adding the adjustment value and the initial focal length to obtain the focusing focal length of the lens. The method and the system have the beneficial effects that the focusing precision and stability of the lens under the condition of image movement or insufficient light are improved, the focusing range of the lens is expanded, and the lens is suitable for ultra-long-distance focusing.

Description

technical field [0001] The invention relates to the technical field of imaging systems, in particular to an automatic focusing method and system based on time-of-flight. Background technique [0002] With the continuous upgrading of the imaging system, the camera technology in various scenarios is also being updated. Focusing is a relatively basic requirement of the imaging system, but if it is more robust, it is quite difficult; in real-time focusing, the image will be affected by light. Interference with scene changes; when there are fast-moving or changing objects inside the scene, the feature value correlation of multiple frames of images on which the focus depends is destroyed. [0003] In the existing technology, in low-light and low-light environments, visible light is absorbed by the environment, and the signal received by the photosensitive part of the imaging system is already weak. At the same time, the noise generated by the imaging system seriously affects the i...

AI Technical Summary

Problems solved by technology

[0002] With the continuous upgrading of the imaging system, the camera technology in various scenarios is also being updated. Focusing is a relatively basic requirement of the imaging system, but if it is more robust, it is quite difficult; in real-time focusing, the image will be affected by light. Interference with scene changes; when there are fast-moving or changing objects inside the scene, the eigenvalue correlation of the multi-frame images on which the focus depends is destroyed

[0003] In the prior art, in low-light and low-light environments, visible light is absorbed by the environment, and the signal received by the photosensitive part of the imaging system is already weak. At the same time, the noise generated by the imaging system seriously affects the imaging quality of the equipment, resulting in blurred images; currently supports from 50 - The focusing method of the imaging range between 3000 meters is not mature, it is difficult or even impossible to deal with the super long-distance focusing situation

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