局部直方图双向拉伸均衡化算法

Local Histogram Bidirectional Stretching Equalization Algorithm

图像在光照不足或过强的情况下会使得拍摄的图像过暗或过亮,看不清图像的轮廓,抓不住图像的细节,这是由于灰度级过于集中导致的,这种图像称为低对比度图像。直方图均衡化可以提高图像的对比度,改善图像的质量,但易出现噪声、细节丢失、过度增强的现象,增强后的图像不适于应用于电子显示设备,如电视、手机等。因此,各学者提出改进的直方图均衡化算法,在拉伸灰度级的同时,保证图像前后的均值稳定。提出的局部直方图双向拉伸均衡化算法(LHBSE),在提高对比度的同时,能更好保证图像前后的均值稳定性,实验效果有所提高。

Under the too weak or too strong light,image will be too dark or too light,which give rise to problems that we cannot see the outline of the image and grasp the image details.This is due to the over-concentration of gray levels,this image is known for low contrast image.Histogram equalization is good for improving image contrast and image quality,but it is prone to noise,loss of detail,over-enhanced phenomenon,the enhanced image is not suitable for using in electronic display devices,such as TV,cell phone and so on.Therefore,scholars propose many improved histogram equalization algorithms to modify the stability of the image.A local histogram bidirectional stretching equalization algorithm(LHBSE)is proposed,which can improve histogram equalization in the way of better contrasting of the image,better ensuring the stability of the image.As a r esult,the experimental results are improved.