Computer Vision and Robotics Group, University of Girona, Girona, Spain.
Comput Med Imaging Graph. 2011 Oct-Dec;35(7-8):646-52. doi: 10.1016/j.compmedimag.2011.03.006. Epub 2011 May 4.
This paper proposes a new color correction pipeline to improve the dermoscopy image quality. Images acquired with different cameras or different dermoscopes often present problems of faithful color reproduction. The colors of these images are often far different the ones observed with the naked eye, and usually vary from one camera to another. Nowadays digital cameras perform "black-box" color corrections taking into account the color temperature of the imaged scene, which may result in some cases in unrealistic color rendering. For this reason, it is necessary to calibrate the imaging system (the camera and a specific dermoscope). The calibration process requires finding a relationship between a device-dependent color space and a standard color space depending only on the human eye. This relation is obtained acquiring known color patches of a color checker and relating them with the pixel values obtained by the camera. In our approach we model the color calibration problem using a new formulation that takes into account the spectral distribution of the dermoscope lighting system and conveys a solution for both RAW and JPEG images. When comparing images captured with different cameras, this new method improves the results between 0.1 and 0.9 ΔE with respect to previous approaches.
本文提出了一种新的颜色校正管道，以提高皮肤镜图像的质量。使用不同的相机或不同的皮肤镜采集的图像通常存在忠实再现颜色的问题。这些图像的颜色通常与肉眼观察到的颜色相差甚远，而且通常因相机而异。如今，数码相机执行“黑盒”颜色校正，考虑到成像场景的色温，这可能导致在某些情况下不真实的颜色渲染。出于这个原因，有必要校准成像系统（相机和特定的皮肤镜）。校准过程需要找到一个设备相关的颜色空间和一个仅依赖于人眼的标准颜色空间之间的关系。通过获取颜色检查器的已知颜色块并将其与相机获得的像素值相关联，可以获得这种关系。在我们的方法中，我们使用一种新的公式来建模颜色校准问题，该公式考虑了皮肤镜照明系统的光谱分布，并为 RAW 和 JPEG 图像传达了一种解决方案。在比较使用不同相机拍摄的图像时，与以前的方法相比，这种新方法将图像之间的差异提高了 0.1 到 0.9ΔE。
