Halftoning curved images

• US 20080181092A1
• Filed: 01/26/2007
• Published: 07/31/2008
• Est. Priority Date: 01/26/2007
• Status: Abandoned Application

• Current Assignee: Hewlett-Packard Development Company, L.P. (HP Inc.)
• Original Assignee: Hewlett-Packard Development Company, L.P. (HP Inc.)
• Inventors: McClellan, Paul J.
• Application Number:
  US11/627,634
• Publication Number:
  US 20080181092A1
• Time in Patent Office: Days
• US Class Current: 369/273
• CPC Class Codes: G11B 7/0037 with discs
• CPC Class Codes: H04N 1/405 Halftoning, i.e. converting the picture signal of a continuous-tone original into a corresponding signal showing only two levels

Abstract

A rectangular image to be imaged on a flat curved surface is received. The rectangular image is converted to a curved image corresponding to the flat curved surface. The curved image is halftoned. The curved image as halftoned is imaged on the flat curved surface.

Claims

1. A method comprising:

receiving a rectangular image to be imaged on a flat curved surface;

converting the rectangular image to a curved image corresponding to the flat curved surface;

halftoning the curved image; and

,

imaging the curved image as halftoned on the flat curved surface.

2. The method of claim 1, wherein halftoning the curved image comprises determining whether a black pixel or a white pixel is to be imaged for each location of a plurality of locations of the curved image, each location having a non-binary value.

3. The method of claim 2, wherein a white pixel is imaged for a location of the curved image by not printing a black pixel at the location.

4. The method of claim 1, wherein halftoning the curved image comprises determining whether a first color pixel or a second color pixel is to be imaged for each location of a plurality of locations of the curved image, each location having a non-binary value

5. The method of claim 1, wherein halftoning the curved image comprises adjusting a halftoning approach designed for rectangular images so that the halftoning approach can be employed in relation to the curved image.

6. The method of claim 1, wherein halftoning the curved image comprises:

for each curved track of a plurality of curved tracks of the flat curved surface,

for each location of a plurality of locations on the curved track,

mapping the location to a corresponding location in a next curved track of the flat curved surface, the location on the curved track mapped to the corresponding location in the next curved track that is most closely adjacent thereto; and

,

employing a halftoning approach designed for rectangular images in relation to the curved image using mappings among the locations of the curved tracks.

7. The method of claim 6, wherein each curved track has a radius defined by CTR=FTR+CTC*TS, where CTR is the radius of the curved track, FTR is the radius of a first curved track of the plurality of curved tracks, CTC is a number of the curved track where the first curved track has a CTC of zero, and TS is a spacing between adjacent curved tracks.

8. The method of claim 7, wherein each location on the curved track has an index CI, where a first location on the curved track has a CI of zero, and wherein the corresponding location in the next curved track for the location on the curved track has an index defined by NI=round(CI+(CI*TS)/CTR), where NI is the index of the corresponding location in the next curved track and round (·

) is a rounding function.

9. The method of claim 6, wherein the tracks are ordered from an innermost track having a smallest radius to an outermost track having a largest radius.

10. The method of claim 6, wherein the curved tracks are spiral tracks.

11. The method of claim 6, wherein the curved tracks are concentric circular tracks.

12. The method of claim 1, further comprising:

performing image enhancement of the rectangular image prior to converting the rectangular image to the curved image; and

,

performing color separation on the curved image prior to halftoning the curved image.

13. The method of claim 1, wherein imaging the curved image as halftoned on the flat curved surface comprises optically writing the curved image as halftoned on an optically writable label surface of an optical disc, such that the flat curved surface is the optically writable label surface of the optical disc.

14. A computer-readable medium having a computer program stored thereon to perform a method comprising:

receiving a rectangular image to be optically written on an optically writable label surface of an optical disc;

converting the rectangular image to a curved image corresponding to the optically writable label surface of the optical disc;

halftoning the curved image; and

,

controlling an optical disc device to optically write the curved image as halftoned on the optically writable label surface of the optical disc.

15. The computer-readable medium of claim 14, wherein halftoning the curved image comprises:

for each curved track of a plurality of curved tracks of the optically writable label surface of the optical disc,

for each location of a plurality of locations on the curved track,

mapping the location to a corresponding location in a next curved track of the optically writable label surface, the location on the curved track mapped to the corresponding location in the next curved track that is most closely adjacent thereto; and

,

employing a halftoning approach designed for rectangular images in relation to the curved image using mappings among the locations of the curved tracks.

16. The computer-readable medium of claim 15, wherein each curved track has a radius defined by CTR=FTR+CTC*TS, where CTR is the radius of the curved track, FTR is the radius of a first curved track of the plurality of curved tracks, CTC is a number of the curved track where the first curved track has a CTC of zero, and TS is a spacing between adjacent curved tracks,

wherein each location on the curved track has an index CI, where a first location on the curved track has a CI of zero, and

wherein the corresponding location in the next curved track for the location on the curved track has an index defined by NI=round(CI+(CI*TS)/CTR), where NI is the index of the corresponding location in the next curved track and round (·

) is a rounding function.

17. The computer-readable medium of claim 15, wherein the curved tracks are one of spiral tracks and concentric circular tracks.

18. An optical disc device comprising:

an optomechanical mechanism capable of optically writing images to an optically writable label surface of an optical disc; and

,

a controller to convert a rectangular image to a curved image corresponding to the optically writable label surface of the optical disc, to halftone the curved image, and to control the optomechanical mechanism to optically write the curved image as halftoned on the optically writable label surface of the optical disc.

19. The optical disc device of claim 18, wherein the controller is to halftone the curved image by:

for each curved track of a plurality of curved tracks of the optically writable label surface of the optical disc,

for each location of a plurality of locations on the curved track,

mapping the location to a corresponding location in a next curved track of the optically writable label surface, the location on the curved track mapped to the corresponding location in the next curved track that is most closely adjacent thereto; and

,

employing a halftoning approach designed for rectangular images in relation to the curved image using mappings among the locations of the curved tracks.

20. The optical disc device of claim 19, wherein each curved track has a radius defined by CTR=FTR+CTC*TS, where CTR is the radius of the curved track, FTR is the radius of a first curved track of the plurality of curved tracks, CTC is a number of the curved track where the first curved track has a CTC of zero, and TS is a spacing between adjacent curved tracks,

wherein each location on the curved track has an index CI, where a first location on the curved track has a CI of zero, and

wherein the corresponding location in the next curved track for the location on the curved track has an index defined by NI=round(CI+(CI*TS)/CTR), where NI is the index of the corresponding location in the next curved track and round (·

) is a rounding function.