An image focusing measure implementation method based on a second-order moment function

Abstract

The invention discloses an image focusing measure implementation method based on a second-order moment function, and belongs to the technical field of information processing. The method comprises thefollowing steps: firstly, preprocessing an image, then partitioning the processed image, and calculating a moment function of each sub-image; And selecting a low-order moment function of each sub-image to construct definition information of the image. And finally, solving the variance of a set formed by the definition information of all the sub-images, and taking the variance value as the focusingmeasurement value of the whole image. According to the invention, on the basis of dividing the image into blocks; a moment function is adopted to construct detail information of the image, the methodis advantaged by simple principle and low computation complexity; Meanwhile, through implementation of the steps, interference of noise on image detail information is reduced to a great extent, so that the focusing measure obtained through the method has high noise robustness, and the method is suitable for a passive imaging system of a camera, especially for high noise resistance under the low-contrast imaging condition, and is suitable for popularization and application.

Description

technical field [0001] The invention belongs to the technical field of information processing, and in particular relates to a method for realizing an image focus measurement based on a second-order moment function. Background technique [0002] Camera equipment in daily life, such as single-lens reflex cameras, mobile phones with camera functions, and monitoring and capture systems at intersections, can all obtain clear images. However, the acquisition of a clear image depends on the automatic focusing performance of the camera device. At present, camera equipment on the market mainly adopts automatic focusing technology of passive imaging. Its core is to design a focus measure for evaluating image clarity, select the clearest image and save it through the focus measure. Therefore, a focus measure implementation method with good performance directly affects the quality of the captured image. [0003] Currently widely used image focus measurement methods are constructed ba...

AI Technical Summary

Problems solved by technology

If the background of the image is relatively uniform or relatively smooth, it is very susceptible to noise at this time, so that the corresponding focus measurement cannot reflect the sharpness information of the image

For example, if you use the camera function of a mobile phone to take pictures indoors or in night scenes with relatively weak lighting conditions, we will find that the autofocus function of the (mobile phone) camera is not easy to use, and the captured images are blurred and grainy

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