Color printer system

A color printer system which includes a host issuing printing instruction and a printer performing printing wherein said host includes:

• image transform decision means for deciding which case of the two following cases results in a greater reduction in a quantity of data transferred from said host to said printer;
• one being that said host performs an image transform and the other being that said printer performs the image transform, thus determining which case should be better for performing the image transform, the case of employing said host and the case of employing said printer;
• first image transform means for performing an image transform processing in said host when said image transform decision means decides that the quantity of data transferred from said host to said printer is more reduced by the image transform processing in said host;
• command preparation means for adding predetermined command information containing flag information indicating whether printing data transferred to said printer is the one before image data transform or after the image data transform and size information of the image to printing data;
• and
• transmission means for transferring data to said printer the data being obtained by adding by the command preparation means, the command information to printing data which has been subjected to the image transform processing of said first image transform;
• and
• wherein said printer includes:
• receiving means for receiving the printing data transmitted from said transmission means of said host;
• second image transform means for performing an image transform processing;
• analysis means for analyzing the printing data received by said receiving means, and deciding whether the image transform processing has already been performed by said first image transform means of said host, thus deciding based on the decision result whether an image transform should be performed by said second image transform means;
• picturing means for preparing picture data from the printing data that has been subjected to the image transfer;
• and
• a printer engine for performing printing on printing paper based on said picture data.

A computer-usable medium having computer-readable program therein for causing a host issuing printing instruction to a printer in a color printer system, to perform the steps of:

• (a) deciding which case of the two following cases results in a greater reduction in a quantity of data transferred from said host to said printer;
• one being that said host performs an image transform processing and the other being that said printer performs the image transform processing, thus determining which should perform the image transform processing, said host or said printer;
• (b) performing an image transform processing in said host when it is decided by an image transform decision means that a performance of the image transform processing in a host results in a greater reduction in the quantity of transferred data, the first image transform means including color transform processing means for exchanging color data between said host and said printer;
• resolution change processing means for magnifying and reducing an original image so that the resolution of said original image on said host is made to be equal to the resolution of said printer, when the resolution of said original image on said host and the resolution of said printer are different from each other;
• and gradient processing means for preparing printing data in accordance with a gradient processing capability of said printer, the printing data having been subjected to the color exchange by said color transform processing means and to the magnification/reduction by said resolution change processing means;
• (c) adding to printing data, command information containing flag information indicating whether printing data transferred to said printer is the one before image data transform or after the image data transform and size information of the image;
• and
• (d) transferring data to said printer, the data being obtained by adding, by a command preparation means, command information to printing data which has been subjected to the image transform processing of said first image transform means and to printing data which has not been subjected to the image transform processing of said first image transform means.

A printer performing printing based on a printing instruction from a host, comprising:

• receiving means for receiving a printing data;
• analysis means for analyzing the printing data received by said receiving means, and deciding whether an image transform processing has been already performed, thus deciding based on the decision result whether an image transform should be performed to said printing data;
• image transform means for performing an image transform processing when said image transform should be performed to said printing data;
• picturing means for preparing picture data from the printing data that has been subjected to the image transfer;
• and
• a printer engine for performing printing on printing paper based on said picture data.