Patent ID: 8718370
Filing Date: 2014-05-06
Classification: G06K

Abstract:
1. An optical information-reading apparatus comprising: an image-capturer capturing an image to convert the image to image data that is represented by a digital brightness value; a partitioner partitioning the image data converted by the image-capturing means into blocks; a brightness-values-measurer measuring brightness values of the image data partitioned into blocks by the partitioning means for every line; an extreme-values-detector comparing the brightness values of the image data of blocks measured by the brightness-values-measuring means for every line and detecting maximum and minimum values thereof; a threshold-value-calculator calculating a binarization threshold value for a block based on the maximum and minimum values detected by the extreme-values-detecting means; an extreme-values-grouper grouping plural adjacent blocks, the threshold values of which are calculated by the threshold-value-calculator, to generate groups; a groups-selector comparing the groups generated by the extreme-values-grouper with a predetermined size to determine whether or not the groups are larger than the predetermined size and selecting the groups if they are larger than the predetermined size; and a binarizer binarizing the brightness value of the image data with the threshold value for blocks in the groups selected by the groups-selector.