Method, system, and program for error checking raster objects

• US 6,738,153 B1
• Filed: 02/08/2000
• Issued: 05/18/2004
• Est. Priority Date: 02/08/2000
• Status: Expired due to Fees

• Current Assignee: Ricoh Company Limited
• Original Assignee: International Business Machines Corporation
• Inventors: Aschenbrenner, Jean Margaret, Hoskins, Phillip Keith, Ludwig, Steven Gary, Hanna, Stephen Dale
• Primary Examiner(s): Grant, II, Jerome
• Application Number:
  US09/499,722
• Time in Patent Office: 1,561 Days
• Field of Search: 358/3.04, 358/3.27, 358/1.14, 358/1.12, 358/406, 358/426.09
• US Class Current: 358/1.14
• CPC Class Codes: G06K 15/00 Arrangements for producing a permanent visual presentation of the output data , e.g. computer output printersprinting or plotting combined with another operation, e.g. with conveying, G06K17/00
• CPC Class Codes: G06K 2215/0085 Error recovery

Abstract

Disclosed is a method, system, and program for error checking raster objects including pixel information for a print job. A plurality of raster objects form the print job. A raster object is received including sequence information indicating an ordering of the raster object with respect to other raster objects in the print job. A determination is made from the sequence information as to whether the raster object is received in a correct order with respect to other raster objects in the print job. This ensures that the pixel information for the raster object is intended for a current pixel line being processed. An indication of error status is made if the sequence information indicates that the raster object was not received in the correct order with respect to the other raster objects in the print job.

Claims

1. A method for error checking raster objects including pixel information for a print job, wherein a plurality of raster objects form the print job, comprising:

receiving a raster object including sequence information indicating an ordering of the raster object with respect to other raster objects in the print job;

determining from the sequence information for the received raster object and a previously received object whether the received raster object is received in a correct order with respect to other raster objects in the print job, to ensure that the pixel information for the raster object is intended for a current pixel line being processed; and

indicating an error status if the sequence information indicates that the raster object was not received in the correct order with respect to the other raster objects in the print job.

2. The method of claim 1, wherein the sequence information includes object type information indicating whether the raster object is one of a first, next, and last raster objects on a sheet, wherein the print job is comprised of multiple sheets, and wherein determining from the sequence information whether the raster object is received in the correct order further comprises:

buffering the object type information for a previously received raster object, wherein the raster object subject to error checking is a current raster object; and

comparing the object type information from the previously received raster object and the object type information of the current raster object to determine whether the raster object is received in the correct order, wherein the raster object is received in the correct order if the object type information indicates one of the following conditions exist;

(i) the current raster object is the first raster object on the sheet and the previous raster object is the last raster object on the sheet;

(ii) the current raster object is the last raster object on the sheet and the previous raster object is the first or next raster object on the sheet;

(iii) the current raster object is the next raster object on the sheet and the previous raster object is the first raster object on the sheet; and

(iv) both the current and previous raster objects are next raster objects on the sheet.

3. The method of claim 2, wherein the sequence information further includes a sequence number indicating the ordering of raster objects on a sheet, wherein determining from the sequence information whether the current raster object is received in the correct order further comprises:

checking whether the sequence number of the current raster object is a first sequence number on the sheet if the object type information indicates that the current raster object is the first raster object on the sheet, wherein the current raster object is received in the correct order if the sequence number is the first sequence number; and

checking whether the sequence number of the current raster object follows the sequence number of the previous raster object if the object type information indicates that the current raster object is the next or last raster object on the sheet, wherein the current raster object is received in the correct order if the sequence number of the raster object follows the sequence number of the previous raster object.

4. The method of claim 2, wherein the object type information indicates whether to print blank for the remainder of the sheet, wherein a current raster object received after a previous raster including object type information indicating to print blank for the remainder of the sheet is in the correct order if the object type information of the current raster object indicates that the current raster object is one of:

(i) the first raster object on the sheet and (ii) an only raster object on the sheet.

5. The method of claim 1, further comprising transmitting the raster object to a decompressor to further process the raster object after performing the error checking.

6. The method of claim 5, wherein each raster object includes pixel information for one color component of a scan line printed by a printer, and wherein all the raster objects that include pixel information for the different color components of a same scan line include sequence information indicating that the raster objects on the same scan line are consecutive with respect to each other, wherein the raster objects including the pixel information for the different color components of the same scan line are transmitted to the decompressor after the error checking to be sent to the printer to print before the raster objects of following scan lines are error checked.

7. The method of claim 1, wherein the raster object and sequence information therein is generated by a raster image processor, further comprising:

sending an error message to the raster image processor that one raster object was processed out of sequence if the error status is indicated; and

regenerating, with the raster image processor, all the raster objects in the sheet for which the error message was generated.

8. A method for error checking raster objects including pixel information for a print job, wherein a plurality of raster objects form the print job, comprising:

receiving a raster object including sequence information indicating an ordering of the raster object with respect to other raster objects in the print job by;

(i) receiving an address of the first raster object on the sheet in memory;

(ii) using the address to access the first raster object from the memory, wherein each raster object on a sheet includes an address of the next raster object on the sheet; and

(iii) after error checking one raster object on the sheet, obtaining the address in the memory of the next raster object on the sheet from the checked raster object, wherein the obtained address is used to access a next raster object on the sheet from the memory

determining from the sequence information whether the raster object is received in a correct order with respect to other raster objects in the print job, thereby ensuring that the pixel information for the raster object is intended for a current pixel line being processed; and

indicating an error status if the sequence information indicates that the raster object was not received in the correct order with respect to the other raster objects in the print job.

9. A system for error checking raster objects including pixel information for a print job, wherein a plurality of raster objects form the print job, comprising:

means for receiving a raster object including sequence information indicating an ordering of the raster object with respect to other raster objects in the print job;

means for determining from the sequence information for the received raster object and a previously received object whether the received raster object is received in a correct order with respect to other raster objects in the print job to ensure that the pixel information for the raster object is intended for a current pixel line being processed; and

means for indicating an error status if the sequence information indicates that the raster object was not received in the correct order with respect to the other raster objects in the print job.

10. The system of claim 9, wherein the sequence information includes object type information indicating whether the raster object is one of a first, next, and last raster objects on a sheet, wherein the print job is comprised of multiple sheets, and wherein the means for determining from the sequence information whether the raster object is received in the correct order further comprises:

means for buffering the object type information for a previously received raster object, wherein the raster object subject to error checking is a current raster object; and

means for comparing the object type information from the previously received raster object and the object type information of the current raster object to determine whether the raster object is received in the correct order, wherein the raster object is received in the correct order if the object type information indicates one of the following conditions exist;

(i) the current raster object is the first raster object on the sheet and the previous raster object is the last raster object on the sheet;

(ii) the current raster object is the last raster object on the sheet and the previous raster object is the first or next raster object on the sheet;

(iii) the current raster object is the next raster object on the sheet and the previous raster object is the first raster object on the sheet; and

(iv) both the current and previous raster objects are next raster objects on the sheet.

11. The system of claim 10, wherein the sequence information further includes a sequence number indicating the ordering of raster objects on a sheet, wherein the means for determining from the sequence information whether the current raster object is received in the correct order further comprises:

means for checking whether the sequence number of the current raster object is a first sequence number on the sheet if the object type information indicates that the current raster object is the first raster object on the sheet, wherein the current raster object is received in the correct order if the sequence number is the first sequence number; and

means for checking whether the sequence number of the current raster object follows the sequence number of the previous raster object if the object type information indicates that the current raster object is the next or last raster object on the sheet, wherein the current raster object is received in the correct order if the sequence number of the raster object follows the sequence number of the previous raster object.

12. The system of claim 10, wherein the object type information indicates whether to print blank for the remainder of the sheet, wherein a current raster object received after a previous raster including object type information indicating to print blank for the remainder of the sheet is in the correct order if the object type information of the current raster object indicates that the current raster object is one of:

(i) the first raster object on the sheet and (ii) an only raster object on the sheet.

13. The system of claim 9, further comprising means for transmitting the raster object to a decompressor to further process the raster object after performing the error checking.

14. The system of claim 13, wherein each raster object includes pixel information for one color component of a scan line printed by a printer, and wherein all the raster objects that include pixel information for the different color components of a same scan line include sequence information indicating that the raster objects on the same scan line are consecutive with respect to each other, wherein the raster objects including the pixel information for the different color components of the same scan line are transmitted to the decompressor after the error checking to be sent to the printer to print before the raster objects of following scan lines are error checked.

15. The system of claim 9, wherein the raster object and sequence information therein is generated by a raster image processor, further comprising:

means for sending an error message to the raster image processor that one raster object was processed out of sequence if the error status is indicated; and

means for regenerating, with the raster image processor, all the raster objects in the sheet for which the error message was generated.

16. A system for error checking raster objects including pixel information for a print job, wherein a plurality of raster objects form the print job, comprising:

means for receiving a raster object including sequence information indicating an ordering of the raster object with respect to other raster objects in the print job by performing;

(i) receiving an address of the first raster object on the sheet in memory;

(ii) using the address to access the first raster object from the memory,

wherein each raster object on a sheet includes an address of the next raster object on the sheet;

(iii) after error checking one raster object on the sheet, obtaining the address in the memory of the next raster object on the sheet from the checked raster object, wherein the obtained address is used to access a next raster object on the sheet from the memory

means for determining from the sequence information whether the raster object is received in a correct order with respect to other raster objects in the print job, thereby ensuring that the pixel information for the raster object is intended for a current pixel line being processed; and

means for indicating an error status if the sequence information indicates that the raster object was not received in the correct order with respect to the other raster objects in the print job.

17. An article of manufacture for use in error checking raster objects including pixel information for a print job, wherein a plurality of raster objects form the print job, the article of manufacture comprising logic for performing:

receiving a raster object including sequence information indicating an ordering of the raster object with respect to other raster objects in the print job;

determining from the sequence information for the received raster object and a previously received object whether the received raster object is received in a correct order with respect to other raster objects in the print job to ensure that the pixel information for the raster object is intended for a current pixel line being processed; and

indicating an error status if the sequence information indicates that the raster object was not received in the correct order with respect to the other raster objects in the print job.

18. The article of manufacture of claim 17, wherein the sequence information includes object type information indicating whether the raster object is one of a first, next, and last raster objects on a sheet, wherein the print job is comprised of multiple sheets, and wherein determining from the sequence information whether the raster object is received in the correct order further comprises:

buffering the object type information for a previously received raster object, wherein the raster object subject to error checking is a current raster object; and

comparing the object type information from the previously received raster object and the object type information of the current raster object to determine whether the raster object is received in the correct order, wherein the raster object is received in the correct order if the object type information indicates one of the following conditions exist;

(i) the current raster object is the first raster object on the sheet and the previous raster object is the last raster object on the sheet;

(ii) the current raster object is the last raster object on the sheet and the previous raster object is the first or next raster object on the sheet;

(iii) the current raster object is the next raster object on the sheet and the previous raster object is the first raster object on the sheet; and

(iv) both the current and previous raster objects are next raster objects on the sheet.

19. The article of manufacture of claim 18, wherein the sequence information further includes a sequence number indicating the ordering of raster objects on a sheet, wherein determining from the sequence information whether the current raster object is received in the correct order further comprises:

checking whether the sequence number of the current raster object is a first sequence number on the sheet if the object type information indicates that the current raster object is the first raster object on the sheet, wherein the current raster object is received in the correct order if the sequence number is the first sequence number; and

checking whether the sequence number of the current raster object follows the sequence number of the previous raster object if the object type information indicates that the current raster object is the next or last raster object on the sheet, wherein the current raster object is received in the correct order if the sequence number of the raster object follows the sequence number of the previous raster object.

20. The article of manufacture of claim 18, wherein the object type information indicates whether to print blank for the remainder of the sheet, wherein a current raster object received after a previous raster including object type information indicating to print blank for the remainder of the sheet is in the correct order if the object type information of the current raster object indicates that the current raster object is one of:

(i) the first raster object on the sheet and (ii) an only raster object on the sheet.

21. The article of manufacture of claim 17, further comprising transmitting the raster object to a decompressor to further process the raster object after performing the error checking.

22. The article of manufacture of claim 17, wherein the raster object and sequence information therein is generated by a raster image processor, further comprising:

sending an error message to the raster image processor that one raster object was processed out of sequence if the error status is indicated; and

regenerating, with the raster image processor, all the raster objects in the sheet for which the error message was generated.

23. An article of manufacture for use in error checking raster objects including pixel information for a print job, wherein a plurality of raster objects form the print job, wherein a pluralty of raster objects form the print job,the article of manufacture comprising logic for performing:

receiving a raster object including sequence information indicating an ordering of the raster object with respect to other raster objects in the print job by;

(i) receiving an address of the first raster object on the sheet in memory;

(ii) using the address to access the first raster object from the memory, wherein each raster object on a sheet includes an address of the next raster object on the sheet; and

(iii) after error checking one raster object on the sheet, obtaining the address in the memory of the next raster object on the sheet from the checked raster object, wherein the obtained address is used to access a next raster object on the sheet from the memory

determining from the sequence information whether the raster object is received in a correct order with respect to other raster objects in the print job, thereby ensuring that the pixel information for the raster object is intended for a current pixel line being processed; and

indicating an error status if the sequence information indicates that the raster object was not received in the correct order with respect to the other raster objects in the print job.

24. An article of manufacture for use in error checking raster objects including pixel information for a print job, wherein a plurality of raster objects form the print job, the article of manufacture comprising logic for performing:

receiving a raster object including sequence information indicating an ordering of the raster object with respect to other raster objects in the print job;

determining from the sequence information whether the raster object is received in a correct order with respect to other raster objects in the print job, thereby ensuring that the pixel information for the raster object is intended for a current pixel line being processed; and

indicating an error status if the sequence information indicates that the raster object was not received in the correct order with respect to the other raster objects in the print job, wherein each raster object includes pixel information for one color component of a scan line printed by a printer, and wherein all the raster objects that include pixel information for the different color components of a same scan line include sequence information indicating that the raster objects on the same scan line are consecutive with respect to each other, wherein the raster objects including the pixel information for the different color components of the same scan line are transmitted to the decompressor after the error checking to be sent to the printer to print before the raster objects of following scan lines are error checked.

25. A computer readable medium containing at least one data structure associated with each raster object including pixel information for a print job for error checking each raster object, wherein a plurality of raster objects form the print job, and wherein the at least one data structure associated with each raster object comprises:

sequence information indicating an ordering of the raster object with respect to other raster objects in the print job, wherein the sequence information for a received raster object and a previously received object is used to determine whether the received raster object is received in a correct order with respect to other raster objects in the print job to ensure that the pixel information for the raster object is intended for a current pixel line being processed.

26. The computer readable medium of claim 25, wherein the sequence information includes object type information indicating whether the raster object is one of a first, next, and last raster objects on a sheet, wherein the print job is comprised of multiple sheets, and wherein the object type information from a previously received raster object and the object type information of a current raster object is compared to determine whether the current raster object is received in the correct order, wherein the current raster object is received in the correct order if the object type information indicates one of the following conditions exist:

(i) the current raster object is the first raster object on the sheet and the previous raster object is the last raster object on the sheet;

(ii) the current raster object is the last raster object on the sheet and the previous raster object is the first or next raster object on the sheet;

(iii) the current raster object is the next raster object on the sheet and the previous raster object is the first raster object on the sheet; and

(iv) both the current and previous raster objects are next raster objects on the sheet.

27. The computer readable medium of claim 26, wherein the sequence information further includes a sequence number indicating the ordering of raster objects on a sheet, wherein the sequence number of the current raster object is a first sequence number on the sheet if the object type information indicates that the current raster object is the first raster object on the sheet, wherein the current raster object is received in the correct order if the sequence number is the first sequence number and if the object type information indicates that the current raster object is the next or last raster object on the sheet, wherein the current raster object is received in the correct order if the sequence number of the raster object follows the sequence number of the previous raster object.

28. A computer readable medium containing at least one data structure associated with each raster object including pixel information for a print job for error checking each raster object, wherein a plurality of raster objects form the print job, and wherein the at least one data structure associated with each raster object comprises:

sequence information indicating an ordering of the raster object with respect to other raster objects in the print job, wherein the sequence information is used to determine whether the raster object is received in a correct order with respect to other raster objects in the print job, thereby ensuring that the pixel information for the raster object is intended for a current pixel line being processed, wherein each raster object includes pixel information for one color component of a scan line printed by a printer, and wherein all the raster objects that include pixel information for the different color components of a same scan line include sequence information indicating that the raster objects on the same scan line are consecutive with respect to each other.