Preprocessing device and method for recognizing image characters

Disclosed is a device and method for recognizing characters in an image. An input part receives the image. A blurring decision part classifies the received image into character blocks and background blocks, calculates an average energy ratio of the character blocks, and compares the average energy ratio with a predetermined threshold to determine whether the received image is blurred. If the received image is not blurred, an image binarization part classifies the received image into character blocks and background blocks, compares pixels in the character blocks with a pixel threshold, binarizes the pixels in the character blocks into a brightness value for a character pixel and a brightness value for a background pixel based on the comparison, and binarizes pixels in the background blocks into the brightness value for a background pixel. A character recognition part recognizes characters in the binarized image.