A method of automatic focusing in the state of large out-of-focus

Abstract

The invention provides an automatic focusing algorithm in a state of large out-of-focus, which is suitable for the needs of using optical large-magnification zoom cameras properly in complex application scenarios such as education recording and broadcasting, video conferencing, etc., and simplifies the operation of zooming and switching The operation of focusing in the scene enhances the experience of using the product and promotes the application of the auto-focus algorithm in real scenes. The present invention comprises the following steps: Step 1, using high-pass and low-pass filters to calculate the high-frequency domain image definition value FV1 and low-frequency domain image resolution value FV2 respectively; Step 2, judging whether the image is in a large out-of-focus state according to FV1 and FV2: Step 3. Use δ(FV) to start the autofocus algorithm in the state of large out-of-focus; Step 4. The autofocus algorithm is as follows: (1) Analysis of the initial search direction; (2) Use FV1 to change the forward speed of the Focus motor frame by frame, based on mountain climbing The algorithm determines the position of the Focus motor corresponding to the clearest image after multiple times of turning back the movement direction of the Focus motor, and sets the focus.

Description

technical field [0001] The invention relates to an automatic focusing method in a large out-of-focus state, which is applied in the field of cameras for educational recording and broadcasting and video conferencing. Background technique [0002] In educational recording and video conferencing, automatic focus algorithms are usually used. For the use of modern imaging technology in education, conferences and other scenarios, such as medium and large classrooms and conference rooms: the length of the room may reach 10 meters or more, and the width is slightly lower than the length or flat. Optical large-magnification zoom camera: 10 times , 12 times, 20 times, 30 times are essential equipment in this application field. When the operator uses the camera for zoom operation, it is often a single control of the Zoom motor to reach the designated zoom position. According to the principle of clear imaging of the zoom lens, the Focus motor needs to reach the corresponding position o...

AI Technical Summary

Problems solved by technology

[0006] In view of this, the purpose of the present invention is to overcome the above-mentioned difficulties, and provide an automatic focusing algorithm in a state of large out-of-focus, which is suitable for properly using large optical magnification zoom in complex application scenarios such as education recording and broadcasting, video conferencing, etc. To meet the needs of the camera, simplify the operator's focusing operation when zooming and switching scenes, enhance the product experience, and promote the application of auto-focus algorithms in real scenes

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