3D Microscope Calibration

摘要

A method calibrates a microscope using a test pattern by capturing a plurality of images of the test pattern with the microscope. The test pattern has a plurality of uniquely identifiable positions across a plurality of repeating and overlapping 2D sub-patterns. The method determines an image contrast metric from the captured image in a selected patch of the test pattern and a reference contrast metric in the corresponding region; and (iii) determines a normalised contrast metric using the reference contrast metric and the image contrast metric. The method estimates depths of the two captured images at the plurality of positions using the normalised contrast metrics and a set of predetermined calibration data for a stack of images captured using the test pattern at a range of depths, and calibrates the microscope using a comparison of the determined depth estimates for the at least two images.

主权项

1. A method of calibrating a microscope using a test pattern, said method including the steps of:
(a) capturing a plurality of images of the test pattern through an optical system of the microscope, said test pattern having a plurality of uniquely identifiable positions across the pattern defined by a plurality of repeating and overlapping 2D sub-patterns; (b) for each of a plurality of corresponding positions on at least two of the captured images:
selecting a patch in the captured image at a position selected from the plurality of uniquely identifiable positions on the test pattern and a corresponding region in the test pattern whereby a location for the corresponding region is determined by the plurality of repeating and overlapping 2D sub-patterns in the test pattern;determining an image contrast metric from the captured image of the test pattern in the selected patch and a reference contrast metric of the test pattern in the corresponding region; anddetermining a normalised contrast metric using the reference contrast metric and the image contrast metric, said normalised contrast metric compensating for an effect of local non-uniform texture of the test pattern; (c) estimating depths of the at least two captured images at the plurality of positions using the normalised contrast metrics and a set of predetermined calibration data for a stack of images captured using the test pattern at a range of depths; and (d) calibrating the microscope using a comparison of the determined depth estimates for the at least two captured images.