Münzenmayer Christian, Paulus Dietrich, Wittenberg Thomas
Fraunhofer Institute for Integrated Circuits IIS, Erlangen, Germany.
IEEE Trans Biomed Eng. 2006 Feb;53(2):254-65. doi: 10.1109/TBME.2005.862534.
This paper presents a new spectral approach to color correction for medical image analysis applications. Linear estimation with regularization by a constrained principal eigenvector method is used for calibration of the camera system and estimation of the illumination spectrum while spectral surface reflectivities are determined by Wiener inverse estimation. Nonlinear devices are handled by piecewise linear interpolation and any linear color preprocessing inside the camera is explicitly modeled. All measurement and estimation processes are combined into a spectral calibration framework for practical application in computer-assisted image analysis. The novelty of our approach lies in the generalization of the image formation model allowing for linear preprocessing inside the camera system. Such transforms would lead to erroneous results with positivity constraint based algorithms or a monochromator based measurement. We provide experimental results from a comprehensive set of reference measurements acquired with a video endoscopy system for gastroscopic application.
本文提出了一种用于医学图像分析应用的色彩校正新光谱方法。通过约束主特征向量法进行正则化的线性估计用于相机系统的校准和照明光谱的估计，而光谱表面反射率则通过维纳逆估计来确定。非线性设备通过分段线性插值处理，并且相机内部的任何线性颜色预处理都被明确建模。所有测量和估计过程都被组合到一个光谱校准框架中，以便在计算机辅助图像分析中实际应用。我们方法的新颖之处在于对图像形成模型的推广，允许相机系统内部进行线性预处理。这种变换会导致基于正性约束的算法或基于单色仪的测量产生错误结果。我们提供了从用于胃镜应用的视频内窥镜系统获取的一组全面参考测量的实验结果。
