ACCURATE SLIDE POSITIONING USING FAST ADAPTIVE-TEMPLATE MATCHING IN AN AUTOMATED MICROSCOPE

Abstract

Abstract In an automated microscope, the stage presents the slide to the optical path in the desired position. This article presents an accurate slide positioning algorithm which finds the relative offset from the zero of off-line calibration when the standard slide with a ring fiduciary mark is loaded on the stage. The relative offset is the difference between the zero by the offset calibration tool and the real-time zero position of the ring mark computed by the scheme. The slide positioning algorithm utilizes the adaptive-template matching method to detect the ring mark precisely, in which a fast sum of absolute differences is employed to reduce the computational complexity of template matching. Computer simulations with real clinical slides containing epithelial debris and nuclei show that the proposed algorithm yields an accurate performance in terms of detecting the ring mark and estimating the relative offset with a great reduction in computational complexity. Keywords: adaptive-template matchingautomated robotic microscopefast sum of absolute differencesslide positioning