Printing apparatus and image output control apparatus for processing image data using a dither pattern

• US 6,646,759 B1
• Filed: 05/14/1997
• Issued: 11/11/2003
• Est. Priority Date: 05/15/1996
• Status: Expired due to Fees

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Koga, Hiroshi
• Primary Examiner(s): Garcia, Gabriel
• Assistant Examiner(s): Poon, King Y.
• Application Number:
  US08/856,174
• Time in Patent Office: 2,372 Days
• Field of Search: 395/1.9, 395/102, 395/114, 358/457, 358/534, 358/535, 358/536, 358/429, 358/455, 358/456, 358/458, 358/459, 358/466, 358/298, 358/2.1, 358/3, 358/3-1-, 358/3-3-, 358/3-1-, 358/504, 358/406, 382/162, 382/264, 382/252, 382/237, 382/254, 382/270, 345/527, 345/596, 345/597, 345/598
• US Class Current: 358/1.9
• CPC Class Codes: G06K 15/02 using printers
• CPC Class Codes: G06K 15/1822 Analysing the received data before processing

Abstract

A printing apparatus is made up of a communicating device for performing a two-way communication with a host system and a dither processing unit for performing a dithering process to inputted image data and forming binary image data on the basis of information regarding an image output transmitted to the host system through the communicating device. The information regarding the image output is at least one of a drawing output of figure/characters, a color, and a gradation expression output. The printing apparatus further has a unit for receiving obtaining instruction information to obtain dithering pattern information in the dither processing unit from the host system through the communicating device and a unit for transmitting the dithering pattern information to the host system through the communicating device in response to the obtaining instruction.

Claims

1. A printing system comprising a host computer and a plurality of printing apparatuses, said host computer being capable of bi-directional communication with said printing apparatuses through communication means, with each of said printing apparatuses comprising:

a memory storing a dither pattern for generating tone-degraded image data based on print data;

image forming means for executing a tone-degrading process on print data input from the host computer, the tone-degrading process using the dither pattern stored in said memory, and for forming an output image;

receiving means for receiving, from the host computer through the communication means, an instruction to request the dither pattern stored in said memory; and

sending means for sending the dither pattern stored in said memory to the host computer through the communication means in response to the instruction,

wherein the host computer executes a tone-degrading process on the print data using the dither pattern in order to display a tone-degraded image.

8. A system according to claim 1, wherein information representing a kind of dither pattern is received in the reception operation by said receiving means.

9. A system according to claim 1, wherein said host computer generates a bit map pattern based on the dither pattern.

10. A system according to claim 1, wherein said host computer performs color space compression to the print data.

2. An image processing method for performing image processing in a printing system in which a host computer is capable of bi-directional communication with a plurality of printing apparatuses, and in which each of the printing apparatuses perform the steps of:

storing a dither pattern for generating tone-degraded image data based on print data;

executing a tone-degrading process on input image data for printing, input from the host computer, by using the stored dither pattern;

outputting the tone-degraded processed image data to an image forming unit;

receiving an instruction from the host computer to request the dither pattern to be used in the tone-degrading process; and

sending the dither pattern to the host computer to be used in the tone-degrading process in response to the instruction,

wherein the dither pattern used in the tone-degrading process for printing is also used by the host computer to form a tone-degraded image for displaying.

11. A method according to claim 2, wherein information representing a kind of dither pattern is received in said receiving step.

12. A method according to claim 2, wherein the host computer generates a bit map pattern based on the dither pattern.

13. A method according to claim 2, wherein the host computer performs color space compression to the print data.

3. A computer-readable medium storing computer-readable program code for an image processing method for performing image processing in a printing system in which a host computer is capable of bi-directional communication with a plurality of printing apparatuses, and in which each of the printing apparatuses performs the steps of:

storing a dither pattern for generating tone-degraded image data based on print data;

executing a tone-degrading process on input image data for printing, input from the host computer, by using the stored dither pattern;

outputting the tone-degraded processed image data to an image forming unit;

receiving an instruction from the host computer to request the dither pattern to be used in the tone-degrading process; and

sending the dither pattern to the host computer to be used in the tone-degrading process in response to the instruction,

wherein the dither pattern used in the tone-degrading process for printing is also used by the host computer to form a tone-degraded image for displaying.

14. A medium according to claim 3, wherein information representing a kind of dither pattern is received in said receiving step.

15. A medium according to claim 3, wherein the host computer generates a bit map pattern based on the dither pattern.

16. A medium according to claim 3, wherein the host computer performs color space compression to the print data.

4. A printing program for an image processing method for performing image processing in a printing system in which a host computer is capable of bi-directional communication with a plurality of printing apparatuses, and in which each of the printing apparatuses performs the steps of:

storing a dither pattern for generating tone-degraded image data based on print data;

executing a tone-degrading process on input image data for printing, input from the host computer, by using the stored dither pattern;

outputting the tone-degraded processed image data to an image forming unit;

receiving an instruction from the host computer to request the dither pattern to be used in the tone-degrading process; and

sending the dither pattern to the host computer to be used in the tone-degrading process in response to the instruction,

wherein the dither pattern used in the tone-degrading process for printing is also used by the host computer to form a tone-degraded image for displaying.

17. A program according to claim 4, wherein information representing a kind of dither pattern is received in said receiving step.

18. A program according to claim 4, wherein the host computer generates a bit map pattern based on the dither pattern.

19. A program according to claim 4, wherein the host computer performs color space compression to the print data.

5. An image processing method for executing an image process to generate a display image, in a system having an image processing apparatus connected to a plurality of printers, said method comprising the steps of:

inputting, to the image processing apparatus, a dither pattern to be used in a tone-degrading process executed in one of the printers;

executing the tone-degrading process on image data for display by using the dither pattern inputted from the printer; and

executing a conversion process corresponding to a characteristic of a display device, on the tone-degraded processed image,

wherein each of the printers comprises;

means for storing a dither pattern for generating tone-degraded image data based on print data;

means for executing the tone-degraded process using the stored dither pattern on input image data; and

means for outputting the tone-degrading processed image data to an image processing unit.

20. A method according to claim 5, wherein the conversion process corresponding to the characteristic of the display device is a color space compression process.

6. An image processing apparatus, connected to a plurality of printers, for executing an image process to generate a display image, said apparatus comprising:

inputting means for inputting a dither pattern to be used in a tone-degrading process executed in one of the printers;

first executing means for executing the tone-degrading process on image data for display by using the dither pattern inputted from the printer; and

second executing means for executing a conversion process corresponding to a characteristic of a display device, on the tone-degraded processed image,

wherein each of the printers comprises;

means for storing a dither pattern for generating tone-degraded image data based on print data;

means for executing the tone-degrading process using the stored dither pattern on input image data; and

means for outputting the tone-degraded processed image data to an image processing unit.

21. An apparatus according to claim 6, wherein the conversion process corresponding to the characteristic of the display device is a color space compression process.

7. A program for performing an image processing method for executing an image process to generate a display image, in a system having an image processing apparatus connected to a plurality of printers, the method comprising the steps of:

inputting, to the image processing apparatus, a dither pattern to be used in a tone-degrading process executed in one of the printers;

executing the tone-degrading process on image data for display by using the dither pattern inputted from the printer; and

executing a conversion process corresponding to a characteristic of a display device, on the tone-degraded processed image,

wherein each of the printers comprises;

means for storing a dither pattern for generating tone-degraded image data based on print data;

means for executing the tone-degrading process using the stored dither pattern on input image data; and

means for outputting the tone-degraded processed image data to an image processing unit.

22. A program according to claim 7, wherein the conversion process corresponding to the characteristic of the display device is a color space compression process.