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

An image processing method for detecting a letter by using a classifier generated through statistical learning of handling a sample image of a fixed size as supervised data, the image processing method comprising:

• a conversion step of acquiring a converted image by geometrically converting a target image containing a letter to be detected such that the target image has a predetermined ratio defining an aspect ratio;
• a search step of searching the converted image for one or more letter candidates each including a region of a possible letter by using the classifier,
• an integration step of applying clustering to the letter candidates searched for in the search step, integrating the letter candidates, and eliminating the letter candidate having a low reliability;
• and
• a circumscribing step of cutting a letter out of the letter candidate that has been integrated and has not been eliminated in the integration step, and generating a rectangle circumscribing the letter.

An image processing computer program operable to cause a computer to execute an image processing method comprising:

• acquiring a converted image by geometrically converting a target image containing a letter to be detected such that the target image has a predetermined ratio defining an aspect ratio;
• searching the converted image for one or more letter candidates each including a region of a possible letter by using the classifier,
• applying clustering to the letter candidates searched for in the searching step, integrating the letter candidates, and eliminating the letter candidate having a low reliability;
• and
• cutting a letter out of the letter candidate that has been integrated and has not been eliminated in the integration step, and generating a rectangle circumscribing the letter.