Electronic device and method for capturing photo based on a preview ratio between an area of a capturing target and and area of a preview image

摘要

A photo capturing method includes recognizing a capturing target of a preview image of a camera device. A preview ratio of the preview image is obtained by calculating a ratio between an area of a smallest rectangle enclosing the capturing target in the preview image and an area of the preview image is calculated. A category that the preview image belongs to is determined according to the capturing target. An average ratio of the determined category is obtained. Once the preview ratio is not equal to the average ratio of the determined category, a capturing range of the camera device is adjusted.