Image processing apparatus, image processing method, and image processing program

An image processing method to be executed by an image processing apparatus comprising:

• setting a reference image to become a reference from among a plurality of images;
• detecting a specific subject from within the set reference image;
• extracting a plurality of feature points from within the reference image such that the average density of number of the feature points become higher in the vicinity of the outline of the detected specific subject than the average density of number of feature points at other regions;
• obtaining corresponding points within the plurality of images other than the reference image that correspond to the extracted feature points;
• and
• converting the coordinates of the positions of each pixel within at least one of the reference image and the other images such that the positions of the feature points and the positions of the corresponding points that correspond to the feature points match, and
• wherein the specific subject is a face,
• the detecting step further comprises discriminating whether an image representing the specific subject is within a detection frame and detecting by scanning the detection frame within the reference image, and
• the vicinity of the outline is at least one of a region inside and a region outside the detection frame having a predetermined width, at a position where the image within the detection frame is discriminated to be an image of the specific subject.

A non-transitory computer readable recording medium having recorded therein an image processing program that causes a computer to execute the procedures of:

• setting a reference image to become a reference from among a plurality of images;
• detecting a specific subject from within the set reference image;
• extracting a plurality of feature points from within the reference image such that the average density of number of the feature points become higher in the vicinity of the outline of the detected specific subject than the average density of number of feature points at other regions;
• obtaining corresponding points within the plurality of images other than the reference image that correspond to the extracted feature points;
• and
• converting the coordinates of the positions of each pixel within at least one of the reference image and the other images such that the positions of the feature points and the positions of the corresponding points that correspond to the feature points match, and
• wherein the specific subject is a face,
• the detecting step further comprises discriminating whether an image representing the specific subject is within a detection frame, and detecting by scanning the detection frame within the reference image;
• and
• the vicinity of the outline is at least one of a region inside and a region outside the detection frame having a predetermined width, at a position where the image within the detection frame is discriminated to be an image of the specific subject.