Patent ID: 6212293
Filing Date: 2001-04-03
Classification: H04N

Abstract:
An image reading device, comprising:a pixel data reading processor that reads pixel data forming an image, each of said pixel data having a value included in a first range;a histogram generating processor that generates a histogram representing a distribution of said pixel data having values included only in a second range which is a part of said first range, said histogram generating processor generates said histogram based on pixel data of said second range which are included in an upper portion, from a maximum value of said first range to a first boundary value which is lower than said maximum value, and a lower portion, from a minimum value of said first range to a second boundary value which is lower than said first boundary value and higher than said minimum value; anda data storage processor that stores data related to said histogram generated by said histogram generating processor, said data storing processor stores first data, related to said upper portion of said pixel data and second data, related to said lower portion of said pixel data, in successive addresses of a memory.