Conventionally, for example, Japanese Laid-Open Patent Publication No. 80791/1987 (Tokukaishou 62-80791) has disclosed a method for recognizing a character image that has been picked up, wherein: image information, such as a character image that has been inputted, is set as a reference pattern, the storage size of a dictionary pattern is set based on the size of the reference pattern, and the image information is recognized based on the dictionary pattern.
Moreover, Japanese Laid-Open Patent Publication No. 74729/1994 (Tokukaihei 6-74729) has disclosed a method wherein: the distance between a character to be recognized and a camera is calculated, a zooming operation of the camera is carried out based on the calculated distance so as to allow the character to be recognized to have a predetermined size so that the character image to be recognized is inputted.
However, the problem with the character recognition device using the conventional methods is that in the case when a character image, which has been temporarily stored, is recognized later, if the character image once stored can not be recognized, the image pick-up operation (reading operation) has to be repeatedly carried out until the character image has been recognized.
For this reason, for example, in the case when a character image, which has been picked up by using a portable-type electronic camera serving as a character recognition device and has been stored therein, is later subject to a character-image recognition at a site different from the site where it was picked up, if the stored character image can not be recognized, the user has to return to the site where it was picked up and re-pick up the same character image.
Furthermore, at the time when a character image is picked up, neither of the character recognition devices using the above-mentioned conventional methods makes a judgment as to whether or not the character image can be recognized. For this reason, even in the case when the character image that has been picked up is recognized at that site, if the character image that has been picked up includes any character that can not be recognized, the picking-up operation (the reading operation) of the character image has to be again carried out upon completion of the recognizing operation.
Another problem with the above-mentioned conventional techniques is that the enlarging operation is applied to even recognizable character images unnecessarily.