Image processing device, image processing method, program, and evaluation method

An image processing device comprising:

• a processor;
• and
• a memory encoded with instructions executed by the processor, the instructions causing the processor to perform operations including
• imaging pluripotent stem cells over time in a culture process of the pluripotent stem cells and acquiring a plurality of images,
• extracting a colony region of the pluripotent stem cells from an image of the plurality of images,
• extracting, from the image, a focused region that is a region based on a group of pixels with luminance values exceeding a standard value from among pixels constituting the image,
• extracting an extraction target region with relatively high contrast in the colony region from the image based on the colony region and the focused region, and
• outputting the extraction target region as an extraction result,
• wherein as a relationship among the colony region, the focused region, and the extraction target region, the colony region is formed, the focused region is then formed in the colony region, and the extraction target region is then formed in the focused region in the culture process of the pluripotent stem cells, and
• the extraction target region is a region with relatively high contrast where a striated pattern appears in the colony region.

An evaluation method for evaluating maturity of a colony of pluripotent stem cells, the method comprising:

• an acquisition process of acquiring a phase contrast image of the colony;
• a detection process of detecting a striated structure including pixels with high luminance in the phase contrast image;
• and
• an output process of outputting an analysis result of maturity of the colony based on a temporal change in the striated structure detected in the detection process.