Color Management in Digital Pathology

In digital microscopes and whole slide imaging systems, images of slides are captured, transmitted, and reproduced on a computer display. In order to allow pathologists to interpret these images accurately and efficiently, it is important that colors from the slides are displayed in a consistent and reliable fashion. The final color of the image presented to the viewing pathologist depends on several steps through the imaging pathway, including sample illumination, magnification, image capture, compression, storage, and reproduction on the computer display.There aremany possible system designs and, within a single system, different setup options which can affect the final image leading to significant variation in image appearances. This paper summarizes recent work by members of the International Color Consortium Medical Imaging Working Group to develop test materials and methods for the assessment of color calibration of digital microscope systems. This work includes sharing of ideas on device calibration and image processing and display. The paper further discusses the challenges encountered in the development of a suitable color target that includes a set of patches with spectra similar to those encountered when viewing pathology slides with stained tissue samples. Background Staining of tissue sections on glass slides is the foundation on which diagnosis and prognosis in pathology are based. In digital microscopes and whole slide imaging (WSI) systems, images of slides are captured, transmitted, and reproduced on a computer display. In order to allow pathologists to interpret these images accurately and efficiently, it is important that colors from the slides are displayed in a consistent and reliable fashion. The final color of the image presented to the viewing pathologist depends on several steps through the imaging pathway, including sample illumination, magnification, image capture, compression, storage, and reproduction on the computer display as shown in Figure 1. There are many possible system designs and, within a single system, different setup options which can affect the final image leading to significant variation in image appearances. We have proposed an objective measure for the color performance of digital microscope systems which allows the overall result of this processing sequence to be assessed. Color Calibration Assessment for Pathology Recognizing the importance of color reproduction, several digital pathology vendors and research groups have attempted to develop color calibration systems for pathology images. Silverstein et al. developed ICC color calibration profiles for three displays focusing on the display end of the imaging workflow [1] using an on-screen color target. The resulting profiles can be used to compare display performance, but as they do not include measurement of the color variation introduced by the imaging device (WSI instrument or digital Hindawi Publishing Corporation Analytical Cellular Pathology Volume 2014, Article ID 652757, 2 pages http://dx.doi.org/10.1155/2014/652757 2 Analytical Cellular Pathology