基于多幅不同曝光量照片的场景高动态范围图像合成

Constructing high dynamic range image based on photographs with different amounts of exposure

提出了一种恢复相机成像系统光照响应曲线,合成场景高动态范围图像的方法.在满足光学成像系统相反法则的前提下,利用多幅同一场景不同曝光量的照片图像,结合最小二乘原理和B样条函数拟合方法,恢复了相机的光照响应曲线,获得图像中像素值与曝光量之间的映射关系,进而将不同曝光量的场景照片图像融合成一幅高动态范围图像.图像中的像素值与场景中对应点的真实亮度值成正比,扩大了场景图像的表示范围,增加了场景图像中高亮区和暗区的细节特征.实验表明,合成的高动态范围图像效果满意.

A method of fusing multiple photographs into a high dynamic range image is presented. Based on the assumption of reciprocity, the photographs of the same scene are taken with different amounts of exposure by digital camera. Using the least squares principle and B-spline function, the response curve of imaging process can be recovered, and the mapping relationship between pixel values and exposures is acquired. On the basis of the response curve, a high dynamic range image, in which the pixel values are proportional to the true radiance values in the scene, can be constructed from the multiple photographs. It will cover the entire dynamic range captured by the original photographs, and some details information of high light or black regions in the scene can be made out. The experimental results show that the constructed high dynamic range images are satisfactory.