Candidate region estimation device, candidate region estimation method, and program

A candidate region estimation method for estimating, for each of a plurality of target objects, a candidate region that is a candidate for a region including said each target object, in an image including the plurality of target objects, the candidate region estimation method comprising:

• receiving, input of the image and region information indicating a region including at least one of the plurality of target objects included in the image;
• detecting boundary lines in the image using a Canny method and a plurality of types of predetermined parameters;
• determining, a parameter to be used when detecting a boundary line of the image, based on a ratio between a density of boundary lines included in the image and a density of boundary lines in a region indicated by the region information;
• detecting, boundary lines in the image using the parameter;
• and
• for each of the plurality target objects included in the image, estimating the candidate region of said each target object based on the boundary lines detected in the boundary line detection step.

A system for estimating a candidate region, the system comprises:

• a processor;
• and
• a memory storing computer-executable program instructions that when executed by the processor cause the system to:
• receive, input of the image and region information indicating a region including at least one of the plurality of target objects included in the image;
• detect boundary lines in the image using a Canny method and a plurality of types of predetermined parameters;
• determine, a parameter to be used when detecting a boundary line of the image, based on a ratio between a density of boundary lines included in the image and a density of boundary lines in a region indicated by the region information;
• detect, boundary lines in the image using the parameter;
• and
• for each of the plurality of target objects included in the image, estimate, by a region estimator, the candidate region of said each target object based on the boundary lines detected in the boundary line detection step.