Patent ID: 8564819

Claim:
An image printing system configured with a host apparatus generating print job data according to image data of an original image and a printing apparatus printing an image on a printing medium by repeating a main scan of a printing head and a conveyance operation to convey the printing medium in a direction intersecting the main scan according to the print job data, the host apparatus comprising: a unit configured to execute index processing which converts a unit pixel having multi-value density data obtained from the image data into a plurality of printing pixels having binary data that defines printing/non-printing of a dot; a unit configured to generate an index start position command notifying the position of a raster for which the index processing has been started; a unit configured to compress the binary data for each raster and generate compressed data; a unit configured to generate a sub-scan direction movement command according to a blank space portion in the image data of the original image in the sub-scan direction; and a unit configured to generate the print job data using the index start position command, the compressed data, and the sub-scan direction movement command, and the printing apparatus comprising: a unit configured to receive the print job data and to arrange a mask pattern which defines allowance or non-allowance of dot printing for each of the printing pixels, according to the index start position command; a unit configured to decompress the compressed data; and a conveyance command generation unit configured to generate a conveyance command for conveying the printing medium in the sub-scan direction according to the sub-scan direction movement command.