Reading system, reading device, reading method, and storage medium

A processor, comprising:

• a first processing circuitry,
• using a candidate image and a mask image to calculate a match ratio indicating a certainty of a segment display being included in the candidate image, the candidate image being extracted from an input image, the candidate image being a candidate of a portion of the input image in which the segment display is imaged, the segment display including a plurality of segment groups, each of the segment groups including a plurality of segments and displaying a number, the mask image being a binary image and including a plurality of mask regions for the segment groups,
• determining that the candidate image is an image of a segment display in a case where the match ratio satisfies a first condition;
• a second processing circuitry
• extracting a contour from the input image,
• calculating a surface area of a region surrounded with the contour,
• extracting, based on the contour, an image having a prescribed shape from the input image when the surface area is not less than a threshold, the threshold being preset, and
• outputting, as the candidate image, the extracted image satisfying a second condition;
• and
• a third processing circuitry reading a numerical value displayed by the segments groups from the candidate image determined to be an image of the segment display.