针对组合四相机拼接影像的亮度差异,提出一种颜色平衡方法。首先,通过相机检校获取相机的辐射响应函数。然后,建立各子相机的颜色模型函数,并依据相邻子影像之间重叠区的亮度信息,通过稳健性估计获取各子影像之间的曝光量差值,完成各子影像之间的颜色差异纠正。最后,定义一个线性权函数,使拼接线附近的影像实现平衡过渡。实验结果表明,该方法能够有效消除各子影像之间的曝光量差异,保证拼接影像颜色均衡,没有明显分界。

In this paper, we propose a color balancing method for correcting uneven illuminations of sub-images of a combined four-head camera. First, the radiometric response function is estimated via a process of camera calibration. Then, based on the overlapped areas of the four sub-images a color correction model is established. Furthermore, a robust estimation method is used to compute the differences of exposure amounts pertaining to the four sub-cameras. Hence, the process of color balancing for a stitched image is accomplished. Finally, a linear weight function is defined to smooth the stitching line. The experiments show that the proposed method is capable of eliminating or compensating the differences of exposure amounts, which guarantees the color unity of the stitched image without unacceptable boundaries.