Image-information transmission method and its control circuit

An image-information transmission method comprising:

• a step prior to transmission, for scanning a header portion of a transmission original at a predetermined scanning line-density, and storing said header portion of image-information in a memory;
• a step for judging an optimum scanning line-density using said read header portion;
• a step for determining a transmission line-density of transmission image-information posted from an object party, after a connection therewith;
• a step for reading said stored image-information header portion from said memory, and transmitting the read stored information header portion at said predetermined line-density, when the determined transmission line-density is in agreement with said predetermined scanning line-density;
• and
• a step for reading said stored image-information header portion from said memory, converting the read image-information header portion into said determined line-density which was determined in said step for determining the transmission line density, and transmitting the converted image information header portion, when the determined transmission line-density is not in agreement with said predetermined scanning line-density.

An image-information transmission method comprising:

• a step for scanning and reading each line a header portion of an original for transmission;
• a step for storing image-signals for each line read;
• a step for comparing contents of a picture element position of image signals of a line currently being scanned and read, at a picture element position which is a same position as a position of stored image signals for one line prior to said stored images and for outputting a high level signal when a scanning line-density is to be high resolution when there is non-agreement said comparison, and outputting a low level signal when a scanning line-density is to be standard resolution when there is agreement in said comparison;
• a step for outputting a picture element clock signal at a same time as a time of the output of picture elements of read image-information of a block period when said high level signal is output;
• a step for counting a number of said picture element clock signals of said block period during which said high level signal is output;
• and
• a step for transmitting a header portion of said original for transmission at high resolution, to an object party destination when a counter value of said counted picture element clock signals has reached a predetermined value.

An image-information transmission control circuit comprising:

• a read means for scanning a head portion of a transmission original;
• a storage means for storing image signal of input line in synchronizing with a picture element clock,
• an exclusive logical sum circuit for comparing contents of picture elements of the same position of picture elements of one prior line and contents of picture element a plural number of other lines by logical sum, and judging whether or not there is agreement of said contents, outputting high level signals when there is non-agreement, and outputting low level signals when there is an agreement;
• a clock output means for outputting picture element clock signals at a time of the output of picture elements of image information read at a clock period at which said high level signals are output from said exclusive logical sum circuit;
• an AND circuit for passing said clock for said picture element clock signal period for which said high level signals are output;
• a counter for counting said picture element clock signals input from said AND circuit, and outputting a carry signal to notify of high resolution at the point, when a count value has attained a threshold value for judgment of a line-density;
• and
• an output means for controlling said carry signals obtained from said counter, and for outputting signals of high resolution, and then clearing a counter value of said counter.