Three-dimensional halftoning area coverage vectors for pixels in each slice of object using selected sub-matrix

• US 10,659,656 B2
• Filed: 03/11/2019
• Issued: 05/19/2020
• Est. Priority Date: 10/29/2014
• Status: Active Grant

• Current Assignee: Hewlett-Packard Development Company, L.P. (HP Inc.)
• Original Assignee: Hewlett-Packard Development Company, L.P. (HP Inc.)
• Inventors: Morovic, Peter, Morovic, Jan, Gondek, Jay S.
• Primary Examiner(s): Rogers, Scott A
• Application Number:
  US16/298,790
• Publication Number:
  US 20190238716A1
• Time in Patent Office: 435 Days
• CPC Class Codes: B29C 64/112 using individual droplets, e.g. from jetting heads
• CPC Class Codes: B29C 64/165 using a combination of solid and fluid materials, e.g. a powder selectively bound by a liquid binder, catalyst, inhibitor or energy absorber
• CPC Class Codes: B29C 64/393 for controlling or regulating additive manufacturing processes
• CPC Class Codes: B33Y 50/00 Data acquisition or data processing for additive manufacturing
• 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

According to examples, area coverage vectors for each pixel on each slice of a digital representation of an object may be determined and a two-dimensional halftone matrix including threshold values may be subdivided into a plurality of sub-matrices, each sub-matrix including threshold values of the halftone matrix in a respective value sub-range. In addition, for each of the slices, a sub-matrix of the plurality of sub-matrices may be selected and the area coverage vectors for the pixels in the slice may be halftoned using respective threshold values of the selected sub-matrix.

Claims

1. A method comprising:

determining, by a processor, area coverage vectors for each pixel on each slice of a digital representation of an object;

subdividing, by the processor, a two-dimensional halftone matrix including threshold values into a plurality of sub-matrices, each sub-matrix including threshold values of the halftone matrix in a respective value sub-range; and

for each of the slices,

selecting, by the processor, a sub-matrix of the plurality of sub-matrices; and

halftoning, by the processor, the area coverage vectors for the pixels in the slice using respective threshold values of the selected sub-matrix.

2. The method of claim 1, further comprising:

depositing material on a layer according to results of the halftoning of the area coverage vectors for the pixels in the slice.

3. The method of claim 2, wherein depositing material further comprises depositing a build material or printing fluid.

4. The method of claim 1, wherein subdividing the two-dimensional halftone matrix further comprises subdividing the two-dimensional halftone matrix into a plurality of sub-matrices of a same size as the two-dimensional halftone matrix.

5. The method of claim 1, wherein subdividing the two-dimensional halftone matrix further comprises subdividing the two-dimensional halftone matrix into a plurality of sequentially arranged sub-matrices.

6. The method of claim 1, wherein selecting the sub-matrix for each of the slices further comprises selecting the sub-matrix for a slice based on a number of the slice modulo a total number of the sequentially arranged sub-matrices.

7. The method of claim 1, further comprising:

partitioning a range of the threshold values into a plurality of equal and disjoint sub-ranges.

8. A system comprising:

a processor; and

a computer-readable medium on which is stored instructions that when executed by the processor, are to cause the processor to;

determine area coverage vectors for each pixel on each slice of a digital representation of an object;

subdivide a two-dimensional halftone matrix including threshold values into a plurality of sub-matrices, each sub-matrix including threshold values of the halftone matrix in a respective value sub-range; and

for each of the slices,

select a sub-matrix of the plurality of sub-matrices; and

halftone the area coverage vectors for the pixels in the slice using respective threshold values of the selected sub-matrix.

9. The system of claim 8, wherein the instructions are further to cause the processor to:

deposit material on a layer according to results of the halftoning of the area coverage vectors for the pixels in the slice.

10. The system of claim 9, wherein the material comprises a build material or printing fluid.

11. The system of claim 8, wherein to subdivide the two-dimensional halftone matrix, the instructions are further to cause the processor to:

subdivide the two-dimensional halftone matrix into a plurality of sub-matrices of a same size as the two-dimensional halftone matrix.

12. The system of claim 8, wherein to subdivide the two-dimensional halftone matrix, the instructions are further to cause the processor to:

subdivide the two-dimensional halftone matrix into a plurality of sequentially arranged sub-matrices.

13. The system of claim 8, wherein to select the sub-matrix for each of the slices, the instructions are further to cause the processor to:

select the sub-matrix for a slice based on a number of the slice modulo a total number of the sequentially arranged sub-matrices.

14. A non-transitory computer-readable medium on which is stored instructions that when executed by a processor, cause the processor to:

determine area coverage vectors for each pixel on each slice of a digital representation of an object;

subdivide a two-dimensional halftone matrix including threshold values into a plurality of sequentially arranged sub-matrices of a same size as the two-dimensional halftone matrix, each sub-matrix including threshold values of the halftone matrix in a respective value sub-range; and

for each of the slices,

select a sub-matrix of the plurality of sequentially arranged sub-matrices;

halftone the area coverage vectors for the pixels in the slice using respective threshold values of the selected sub-matrix; and

deposit material on a layer according to results of the halftoning of the area coverage vectors for the pixels in the slice.

15. The computer-readable medium of claim 14, wherein the instructions are further to cause the processor to:

select the sub-matrix for a slice based on a number of the slice modulo a total number of the sequentially arranged sub-matrices.