Noise estimation and reduction on five medical liquid-crystal displays

Liquid-crystal displays (LCDs) are replacing cathode-ray tube (CRT) displays as primary diagnostic viewing devices in clinics. They exhibit higher spatial noise than CRTs, which can interfere with diagnosis and reduce the efficiency especially when subtle abnormalities are presented. A study by the authors on LCD spatial noise has recently been reported. A high-quality CCD camera was used to acquire images from the LCD. Noise properties were estimated from the digital-camera images. Then, an error-diffusion-based operation was applied to reduce the display spatial noise. This paper presents the noise estimation and reduction results on five different medical-grade LCDs using the same study protocol. These five different LCDs vary in terms of matrix size, pixel size, pixel structure, and vendors. The purpose of this work is to demonstrate that the LCD spatial-noise estimation and reduction scheme proposed earlier by the authors is valid, robust, and necessary for various medical-grade LCDs used in clinics today.