Next, the character area extracting device binarizes the reflective area at a second threshold level to separate a character region and a background area.

Should a second prospective character region arise in the expected area in the subsequent image, the first prospective character region is associated with the second prospective character region to form or expand a 'track'.

Similarly, the character area extracting device binarizes the non-reflective area at a third threshold level to separate a character area and a background area.

For a first prospective character region identified in a first image, it is determined from a predetermined expected target trajectory where the character region would be expected to occur in a subsequent image.

The character area extracting device integrates each of the character areas of the reflective and non-reflective areas to specify position information of the character areas in the image data.

Identifying a character region in an image involves identifying in each of a plurality of images in time series one or more prospective character regions.

From the comparison a score is calculated indicating the likelihood that the segment contains a character region.