Process for automatic focusing

A kind of automatic focus and technical technology, applied in the field of intelligent multi-point focus technology, can solve the problems of finding the best focus position, not working normally, insufficient ambient brightness, etc., and achieve the effect of reducing processing power requirements and accurate focusing

CN1464323AInactive Publication Date: 2003-12-31GUANGDONG VIMICRO
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Patent Information

Authority / Receiving Office
CN · China
Current Assignee / Owner
Publication Date
2003-12-31
Estimated Expiration
Not applicable · inactive patent

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Abstract

The automatic focusing technology is used for finding out optimized focus position in the cases of insufficient background brightness, over large distance between the taken body and the background and varying background during focusing. The automatic focusing process includes the following steps: adjusting the focal length of the lens in the focusing range to obtain one frame of digital image in each relative position; separating the digital image into several regions and finding out the evaluation value for each region; weighting each region; finding out relative position evaluation value to the digital image found for each relative position based on the region evaluation value and region weight; recording the relative position with maximum evaluation value and focusing the lens to the position as optimal focusing position.
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Description

technical field

[0001] The invention relates to an automatic focus technology, in particular to an intelligent multi-point focus technology used in a digital imaging system. Background technique

[0002] In the process of image shooting, the distance between the camera or video camera and the object is often changed, so the image is often blurred due to exceeding the depth of field range. In order to keep the image clear, it is necessary to change the focus position of the lens during the viewfinder process to keep the image clear. This process of adjusting the focus position is called focusing or focusing.

[0003] Autofocus technology has been widely used in imaging fields such as cameras, video cameras, and image scanning. It enables the imaging system to automatically adjust the position of the focusing lens group in the lens according to the distance of the object, so that the object is clearly imaged on the imaging plane. There are many kinds of autofocus methods in...

Examples

Embodiment Construction

[0047] The present invention will be described in more detail below in conjunction with the accompanying drawings and non-specific embodiments.

[0048] The digital imaging system adopting the intelligent multi-point focus technology of the present invention at least includes lens, photosensitive sensor such as CCD or CMOS sensor, A / D conversion circuit, exposure detection circuit, focus detection circuit, microcomputer, RAM and transmission mechanism, etc. part.

[0049] Take a digital camera as an example: figure 1 Shown is a block diagram of a digital camera using intelligent multi-point focusing technology, including an automatic zoom lens 10, a CCD or CMOS sensor 11, an A / D conversion circuit 12, an exposure detection circuit 13, a focus detection circuit 14, and a microcomputer 15 , RAM16, shutter switch 17, autofocus switch 18, flashlight 19 and transmission mechanism 20 etc. several parts.

[0050] Such as figure 2 Shown is to adopt the digital camera work flow ch...