Image dark corner removing method and device for large visual field camera

Abstract

The invention dioceses an image dark corner removing method and device for a large visual field camera. Whether a dark corner exists in an image or not is judged according to symmetry of radial gradient distribution of the image; the dark corner is estimated through statistic features of the whole image; and different from a traditional method of estimating the dark corner by selecting a square area with a fixed size, the method is applicable to the images of different resolutions and is applicable to the images with relatively large dark corners, and a possibility of occurring deviation is relatively low. According to the method and the device, parameters are designed according to the to-be-corrected image, the universality is high, the method and the device are applicable to the images with different dark corner effects formed under different illumination and different environments, the application range is relatively wide, and a special camera is not limited. According to the method and the device, model parameters are simplified and solved according to engineering experience, and the calculation quantity is greatly reduced. According to the image dark corner removing method provided by the invention, a chip does not need to be burnt in advance, so the burnout records of the chip can be reduced, and the production cost can be reduced.

Description

Image de-vignetting method and device of large-field camera Technical field The present invention relates to the technical field of image processing, in particular to a method and device for removing dark corners of images of a camera with a large field of view. Background technique Fish-eye cameras are widely used in photography, vehicle surround view systems, and large-scale environmental monitoring due to their large field of view. The pictures taken by the fisheye camera show a strong vignetting effect. The vignetting effect appears as a gradually darkened area extending outward in a fan shape at the four corners of the image. The reasons are as follows: 1. The light passing through the edge of the sensor is farther than the light path through the center of the sensor, and the light has a certain attenuation; 2. The light flux illuminating the sensor decreases from the center to the surroundings. The above factors lead to the uneven exposure of the image captured by the ...

AI Technical Summary

Problems solved by technology

The image vignetting brightness adjustment method and device implementing the technical solution can automatically adjust the brightness of the image vignetting during the process of shooting with the image capture device, so that the brightness of the whole image after adjustment is kept consistent, and the comfort of image viewing is improved. However, its technical solution is to select a fixed-size square area (80 to 120 pixels in length) and count the average value of pixels in this area as a parameter for adjusting the vignetting of the image. There are the following technical problems: 1. It cannot be applied to images of different resolutions

2. Whe

Images