Multi-Scale Visual Servoing Framework for Optical Microscopy Based on SIFT Matching

This letter introduces an innovative multi-scale visual servoing framework for optical microscopy, engineered to automatically reposition the microscope for high-magnification target view across multiple magnifications, thereby facilitating repetitive and accurate histologic biopsies. The framework encompasses an active microscope-camera system equipped with both auto-calibration and multi-scale visual servoing capabilities. The auto-calibration technique addresses the challenges posed by the limited depth of field and pattern requirements of the microscope-camera system, and determines its intrinsic and hand-eye parameters through a two-step algorithm. The calibration data is then utilized to execute a SIFT matching-based visual servoing control at progressively increasing magnifications, using only a single high-magnification target view as a reference, ultimately enabling rapid and precise repositioning of the microscope. Experimental results demonstrate the precision and stability of the auto-calibration method, as well as the robustness of the visual servoing method against occlusion, blur, and low illumination.