Cell colony area specifying apparatus, cell colony area specifying method, and recording medium

A cell colony area specifying method for specifying an area of a cell colony in a colony image representing said cell colony, comprising:

• a) obtaining an initial boundary image provisionally representing a boundary of a cell colony from a colony image;
• b) acquiring a provisional boundary image by deleting a small area from said initial boundary image;
• c) obtaining a provisional boundary thin-line image by performing a thinning processing on said provisional boundary image;
• d) obtaining a mask image by performing a thickening processing on said provisional boundary thin-line image;
• e) obtaining an updated provisional boundary image by masking said initial boundary image with said mask image;
• f) connecting end points adjacent to each other in said updated provisional boundary image;
• g) checking whether a predetermined repeat end condition is satisfied or not after said operation e) and before or after said operation f), and returning to said operation c) after said operation f) when said repeat end condition is not satisfied, or obtaining a boundary thin-line image from an image obtained after said operation f) and going to an operation h) when said repeat end condition is satisfied;
• and
• h) specifying an area surrounded by a line in said boundary thin-line image, as an area of a cell colony.

A non-transitory computer-readable recording medium for recording therein a program to cause a computer to specify an area of a cell colony in a colony image representing said cell colony,

• said program being executed by said computer to cause said computer to perform:
• a) obtaining an initial boundary image provisionally representing a boundary of a cell colony from a colony image;
• b) acquiring a provisional boundary image by deleting a small area from said initial boundary image;
• c) obtaining a provisional boundary thin-line image by performing a thinning processing on said provisional boundary image;
• d) obtaining a mask image by performing a thickening processing on said provisional boundary thin-line image;
• e) obtaining an updated provisional boundary image by masking said initial boundary image with said mask image;
• f) connecting end points adjacent to each other in said updated provisional boundary image;
• g) checking whether a predetermined repeat end condition is satisfied or not after said operation e) and before or after said operation f), and returning to said operation c) after said operation f) when said repeat end condition is not satisfied, or obtaining a boundary thin-line image from an image obtained after said operation f) and going to an operation h) when said repeat end condition is satisfied;
• and
• h) specifying an area surrounded by a line in said boundary thin-line image, as an area of a cell colony.

A cell colony area specifying apparatus for specifying an area of a cell colony in a colony image representing said cell colony, comprising:

• an image pickup part for picking up an image of a cell colony, to acquire a colony image;
• an operation part for specifying an area of said cell colony in said colony image by performing a computation processing;
• and
• an output part for outputting said area which is specified,
• wherein said operation part performs:
• a) obtaining a lightness change image representing a difference in lightness between each position in said colony image and its periphery;
• b) obtaining a lightness change binary image by binarizing said lightness change image;
• c) obtaining a small area fill image by filling a closed area whose area is not larger than a predetermined area in said lightness change binary image;
• d) obtaining a thin line image by performing a thinning processing on said small area fill image;
• e) obtaining a corrected thin line image by deleting a small projection in said thin line image;
• f) obtaining a colony fill image by filling a closed area in said corrected thin line image;
• g) obtaining a colony boundary image representing a boundary of a cell colony from an image obtained by taking a logical product of said colony fill image and said lightness change binary image or another lightness change binary image obtained from said colony image by another method;
• and
• h) specifying an area of a cell colony on the basis of said colony boundary image.

A cell colony area specifying apparatus for specifying an area of a cell colony in a colony image representing said cell colony, comprising:

• an image pickup part for picking up an image of a cell colony, to acquire a colony image;
• an operation part for specifying an area of said cell colony in said colony image by performing a computation processing;
• and
• an output part for outputting said area which is specified,
• wherein said operation part performs:
• a) obtaining a colony binary image by binarizing said colony image with a threshold value which separates an area of a cell colony from the other area;
• b) obtaining a peripheral binary image by binarizing said colony image with a threshold value which separates a strip-like area appearing around said cell colony from the other area;
• c) performing a thickening processing on at least one of said colony binary image and said peripheral binary image;
• d) obtaining an initial boundary image by taking a logical product of said colony binary image and said peripheral binary image which are obtained after said operation c);
• and
• e) specifying an area of a cell colony on the basis of said initial boundary image.

A cell colony area specifying method for specifying an area of a cell colony in a colony image representing said cell colony, comprising:

• a) obtaining a lightness change image representing a difference in lightness between each position in a colony image and its periphery;
• b) obtaining a lightness change binary image by binarizing said lightness change image;
• c) obtaining a small area fill image by filling a closed area whose area is not larger than a predetermined area in said lightness change binary image;
• d) obtaining a thin line image by performing a thinning processing on said small area fill image;
• e) obtaining a corrected thin line image by deleting a small projection in said thin line image;
• f) obtaining a colony fill image by filling a closed area in said corrected thin line image;
• g) obtaining a colony boundary image representing a boundary of a cell colony from an image obtained by taking a logical product of said colony fill image and said lightness change binary image or another lightness change binary image obtained from said colony image by another method;
• and
• h) specifying an area of a cell colony on the basis of said colony boundary image.

A cell colony area specifying method for specifying an area of a cell colony in a colony image representing said cell colony, comprising:

• a) obtaining a colony binary image by binarizing a colony image with a threshold value which separates an area of a cell colony from the other area;
• b) obtaining a peripheral binary image by binarizing said colony image with a threshold value which separates a strip-like area appearing around said cell colony from the other area;
• c) performing a thickening processing on at least one of said colony binary image and said peripheral binary image;
• d) obtaining an initial boundary image by taking a logical product of said colony binary image and said peripheral binary image which are obtained after said operation c);
• and
• e) specifying an area of a cell colony on the basis of said initial boundary image.

A non-transitory computer-readable recording medium for recording therein a program to cause a computer to specify an area of a cell colony in a colony image representing said cell colony,

• said program being executed by said computer to cause said computer to perform:
• a) obtaining a lightness change image representing a difference in lightness between each position in a colony image and its periphery;
• b) obtaining a lightness change binary image by binarizing said lightness change image;
• c) obtaining a small area fill image by filling a closed area whose area is not larger than a predetermined area in said lightness change binary image;
• d) obtaining a thin line image by performing a thinning processing on said small area fill image;
• e) obtaining a corrected thin line image by deleting a small projection in said thin line image;
• f) obtaining a colony fill image by filling a closed area in said corrected thin line image;
• g) obtaining a colony boundary image representing a boundary of a cell colony from an image obtained by taking a logical product of said colony fill image and said lightness change binary image or another lightness change binary image obtained from said colony image by another method;
• and
• h) specifying an area of a cell colony on the basis of said colony boundary image.

A non-transitory computer-readable recording medium for recording therein a program to cause a computer to specify an area of a cell colony in a colony image representing said cell colony,

• said program being executed by said computer to cause said computer to perform:
• a) obtaining a colony binary image by binarizing a colony image with a threshold value which separates an area of a cell colony from the other area;
• b) obtaining a peripheral binary image by binarizing said colony image with a threshold value which separates a strip-like area appearing around said cell colony from the other area;
• c) performing a thickening processing on at least one of said colony binary image and said peripheral binary image;
• d) obtaining an initial boundary image by taking a logical product of said colony binary image and said peripheral binary image which are obtained after said operation c);
• and
• e) specifying an area of a cell colony on the basis of said initial boundary image.