Image data storing system

Claim 1

An image data storage system for storing image data representing an image, said system comprising: a map memory having a two-dimensional format and being divided into a plurality of (p×q) of memory regions corresponding to (p×q) image units which may or may not contain image information, said image units being obtained by two-dimensionally dividing an image, each of said image units consisting of a matrix of M×N bits, wherein p is the number of image units in the horizontal scanning direction; q, the number of image units in the vertical scanning direction; M, the number of bits in one image unit in the horizontal scanning direction; and N, the number of bits in one image unit in the vertical scanning direction, and a data memory for storing image data representing said image units, each said memory region in said map memory storing a pointer which indicates an address of said data memory at which said image data are stored when image information exists in said one image unit, said map memory storing a predetermined number when no image information exists in said one image unit, wherein said data memory is not accessed for a particular map memory location when said location contains said predetermined number.

Claim 9

A method for operating an image conversion system which includes a buffer to which an image input signal is applied in data words of a predetermined number of data bits, first means for detecting the end of each line in said image input signal, second means for counting an output of said first means to count a number of lines, a map memory which is addressed each time one word of said image input signal is received, a data memory having a plurality of memory areas, each of which corresponds to a respective pointer stored in said map memory, a first pointer register to which a first pointer value of said map memory is inputted, a second pointer register to which a predetermined value is inputted, and third means for setting a new pointer value in said first pointer register, said method comprising the steps of: (1) if data of one word applied to said buffer are data other than all "0"s and the corresponding pointer value of said map memory inputted to said first pointer register is "0", storing data of said second pointer register in said map memory and writing the data of said one word in said data memory with said predetermined value as an address; (2) if data of said one word applied to said buffer are data other than all "0"s and the corresponding pointer value of said map memory inputted to said first pointer register is not "0", writing the data of said one word into said data memory with said first pointer value as an address; (3) if data of said one word applied to said buffer is all "0"s, returning to said step (1) and processing a new data word in said buffer without accessing said map memory and data memory; and (4) repeating said steps (1) to (3) the same number of times as a predetermined number of lines for a region of said map memory which corresponds to one unit of an image to be converted.

Claim 10

A method for operating an image conversion system which includes a buffer to which an image input signal is applied in data words of a predetermined number of data bits, first means for detecting the end of each line in said image input signal, second means for counting an output of said first means to count a number of lines, a map memory which is addressed each time one word of said image input signal is received, a data memory having a plurality of memory areas, each of which corresponds to a respective pointer stored in said map memory, a first pointer register to which a first pointer value of said map memory is inputted, a second pointer register to which a predetermined value is inputted, and third means for setting a new pointer value in said first pointer register, said method comprising the steps of: (1) if data of one word applied to said buffer are data other than all "0"s and the corresponding pointer value of said map memory inputted to said first pointer register is "0", storing data of said second pointer register in said map memory and writing the data of said one word in said data memory with said predetermined value as an address; (2) if data of said one word applied to said buffer are data other than all "0"s and the corresponding pointer value of said map memory inputted to said first pointer register is not "0", writing the data of said one word into said data memory with said first pointer value as an address; (3) if data of said one word applied to said buffer is all "0"s, returning to said step (1) and processing a new data word in said buffer without accessing said map memory and data memory; and (4) repeating said steps (1) to (3) the same number of times as a predetermined number of lines for a region of said map memory which corresponds to one unit of an image to be converted.