	US 7,590,275 B2
	Method and system for recognizing a candidate character in a captured image
Ian Clarke, Toronto (Canada); Hui Zhou, Toronto (Canada); and Jeffrey Matthew Achong, Brampton (Canada)
Assigned to Seiko Epson Corporation, Tokyo (Japan)
Filed on Aug. 26, 2004, as Appl. No. 10/926,658.
Prior Publication US 2006/0045322 A1, Mar. 02, 2006
Int. Cl. G06K 9/00 (2006.01)

U.S. Cl. 382—137 [705/45]

29 Claims

1. A method of identifying candidate characters of a character string in a captured image, the method comprising using a processor to perform the steps of:

identifying special characters within the captured image of said character string, including:

performing a Fast Fourier Transform (FFT) on a portion of the captured image;

performing an inverse FFT yielding a cross-correlation image representing a cross-correlation between the captured image and a character template image corresponding to the special characters;

box-filtering the cross-correlation image to smooth the cross-correlation image;

subtracting the box-filtered image from the cross-correlation image yielding a modified cross-correlation image; and

based at least in part on the modified cross-correlation image, identifying the special characters;

determining a bounding box generally encompassing said character string based on the identified special characters;

determining segments of said bounding box containing candidate characters;

comparing each determined segment of said bounding box with at least one character template image, each character template image including features associated with a respective character to be recognized; and

identifying a candidate character when said segment includes image information corresponding to one of a set of character template images.