Research On Image Contrast Enhancement Method Based On Gamma Correction

High visibility images have a deeper impression on people's subjective vision,which can not only reflect the clear details of the target scene,but also have higher practical value.For example,object detection and recognition.However,in the process of image acquisition,it is often limited by imaging equipment,lighting conditions,photography technology and other quality degrading factors,so it is inevitable to obtain low illumination images.The dynamic range of this kind of image is narrow,the tone is dark,the detail is lost,and there is noise influence.Therefore,for low illumination images,it is particularly important to enhance the contrast of the image and improve the visual effect of the image.Digital image contrast enhancement technology plays an important role in digital image processing,pattern recognition,computer vision and other fields.In this paper,image contrast enhancement methods based on Gamma correction and several classical image contrast enhancement methods in digital image processing are systematically studied.After fully understanding the advantages and disadvantages of each algorithm,the advantages of each algorithm are combined.Forming a new image contrast enhancement method.For low illumination images,a hybrid histogram correction method based on Gamma correction is proposed by combining histogram equalization algorithm and weighted distribution adaptive Gamma correction algorithm with illuminace weight w to enhance image contrast.The results of this method are not ideal and can be further enhanced.Therefore,this paper proposes two methods to improve the defects of this method.The first method is to further enhance the illuminace of pixels below a certain illuminace value in the enhanced image by using the traditional Gamma correction algorithm.Or the image can be enhanced by using the multi-scale Retinex algorithm,and then the enhanced component is input into the gamma-correction-based hybrid histogram correction method for processing.The second method: Combined with the research direction of the subject,use Gamma correction to suppress the enhancement effect of multi-scale Retinex algorithm after image processing,and then use the newly proposed illuminace weight k combined with the mixed histogram correction method based on Gamma correction to enhance the image contrast.The experimental results show that the second improved method can improve the image contrast to a greater extent,and the subjective visual effect of the enhanced image is better,and the objective evaluation results are more advantageous,and it has more practical application value.