Automatic focusing method and system, and shooting device

Abstract

The invention relates to an automatic focusing method and system, and a shooting device. The method comprises: a preview image generated by an imaging device is obtained; face identification is carried out on the preview image, a face contour feature frame is determined, and dimension information of the face contour feature frame is obtained; and according to the dimension information of the face contour feature frame, a preset object distance, a reference dimension information of the face contour feature frame, and a preset correction coefficient, a current object distance is determined, and automatic focusing is carried out based on the current object distance. According to the invention, an object distance can be calculated rapidly and automatic focusing is carried out; the focusing speed is fast; sacrifice of masked pixels as well as manufacturing cost increasing can be avoided; and the using requirement of the front camera is met.

Description

technical field

[0001] The invention relates to the field of imaging technology, in particular to an autofocus method and system, and a photographing device. Background technique

[0002] Generally speaking, the auto-focus technology means that the shooting device will move the lens to change the distance between the lens and the object to be photographed, so as to obtain the subject image with maximum clarity.

[0003] Existing mobile devices, such as smart phones, are equipped with a front camera and a rear camera. The front camera is often used for self-portraits, but the front cameras of mobile devices on the market use fixed focus due to various reasons. Autofocus cannot be achieved. Commonly used autofocus technologies for rear cameras include contrast detection focusing, PDAF phase focusing, and infrared focusing. Among them, contrast focusing is carried out in the main sensor CMOS in the shooting device, and the focus point can be set arbitrarily within a wide rang...

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