Automatic focusing system and method

Abstract

The invention discloses a method for an automatic focusing digital imaging device. The method comprises the following steps: (1) capturing a plurality of images, each image being captured at different positions of a lens of the imaging device; (2) generating a high spatial frequency value for each image, each high spatial frequency value representing the high spatial frequency information in the image; (3) determining the image with the largest high spatial frequency value; and (4) adjusting the lens to a position corresponding to the position at which the image with the largest high spatial frequency value is captured.

Description

Invention field [0001] The invention relates to an automatic focusing method and system used in a digital imaging device. Background technique [0002] Digital imaging devices can be classified as auto-focus (auto-focus) or fixed-focus devices. Fixed focusing devices usually cannot adjust the lens or change the aperture, but instead rely on the large depth of field where the target appears in focus. Although the images captured by fixed focus devices are acceptable in many situations, they are not as sharp as those captured by autofocus devices. [0003] The image captured at the focal point of the lens is a sharp-focus image. Here, the focal point refers to the point on the lens axis of the camera where light converges. However, even if the target is not in focus, if the target is in the depth of field of the lens, a sufficiently clear target image, that is, a sharp focus image, can be generated. The depth of field refers to the distance from the camera within which the capture...

AI Technical Summary

Problems solved by technology

[0006] Although autofocus digital imaging devices generally perform better than fixed focus imaging devices, prior art autofocus devices are typically more complex in hardware, more expensive to manufacture and slower in operation than fixed focus devices

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