Patent ID: 9600710
Date: 2017-03-21
CPC Classifications: G01N,G02B,G06K,G06T,H04N

Claim:
1. A method of analysis of a sample of biological tissue cells disposed on a platform, the sample being a thin phase object and the platform being substantially transparent, the method comprising the steps of: acquiring at least first and second images of the sample from light passing through the platform and the sample, the images having different focal heights relative to the platform, and each of the acquired images comprising a matrix of pixels; computing a contrast matrix having elements corresponding to the pixels in the acquired images by setting the value of each element of the contrast matrix in dependence upon the difference between the values of the corresponding pixels in the first and second images; computing a phase matrix having elements corresponding to the elements in the contrast matrix by performing a convolution of the contrast matrix and a predetermined distance index matrix; and using the phase matrix to assess characteristics of the sample, wherein said predetermined distance index matrix comprises elements where each element, other than a center element, has a value that is inversely proportional to a distance between that image and the center element.