Three-dimensional threshold matrix for three-dimensional halftoning

• US 10,445,929 B2
• Filed: 04/16/2015
• Issued: 10/15/2019
• Est. Priority Date: 04/16/2015
• 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., Garcia Reyero Vinas, Juan Manuel
• Primary Examiner(s): Wu, Yanna
• Application Number:
  US15/544,504
• Publication Number:
  US 20170365095A1
• Time in Patent Office: 1,643 Days
• Field of Search: None
• CPC Class Codes: B33Y 50/00 Data acquisition or data processing for additive manufacturing
• CPC Class Codes: G06T 17/10 Constructive solid geometry [CSG] using solid primitives, e.g. cylinders, cubes
• 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

Certain examples described herein relate to a three-dimensional threshold matrix. The three-dimensional threshold matrix may be used for three-dimensional halftoning. In one example, values for a predefined two-dimensional threshold matrix are shifted with respect to a third dimension to provide the three-dimensional threshold matrix. In one example, the three-dimensional threshold matrix may then be processed in association with a digital representation of a three-dimensional object to output discrete material arrangement instructions for at least one production material. The instructions may be used to control an additive manufacturing system to produce the three-dimensional object.

Claims

1. An apparatus to generate control data for production of a three-dimensional object comprising:

a processor; and

a non-transitory storage medium on which is stored instructions that are to cause the processor to;

apply a halftoning operation to a digital representation at least a portion of the three-dimensional object, wherein the instructions are to cause to the processor to process the digital representation of at least the portion of the three-dimensional object in association with a three-dimensional threshold matrix to output discrete material arrangement instructions for at least one production material;

generate the three-dimensional threshold matrix for use by the halftone generator, wherein to generate the three-dimensional threshold matrix, the instructions are to cause the processor to;

obtain values for a predefined two-dimensional threshold matrix; and

extend the predefined two-dimensional threshold matrix into a third dimension to generate the three-dimensional threshold matrix by laterally- shifting, with respect to the third dimension and according to a defined sequence, at least a subset of the values in subsequent matrices in a set of two-dimensional matrices with respect to the predefined two-dimensional threshold matrix, each matrix in the set of two-dimensional matrices comprising the at least a subset of the values for the predefined two-dimensional threshold matrix,

wherein the digital representation of at least the portion of the three-dimensional object comprises at least one material volume coverage vector for at least one volume of the three-dimensional object,

wherein, for k materials available for production of the three-dimensional object and L discrete deposit states for said materials, the at least one material coverage vector comprises L^k vector components, each vector component having an associated probability value, and

wherein the discrete material arrangement instructions comprise production instructions from a set of L * k available instruction values, each element at a production resolution having one of L deposit state instructions for each of said k materials.

2. The apparatus according to claim 1, comprising:

a deposit mechanism to deposit available production materials according to the outputted discrete material arrangement instructions.

3. The apparatus according to claim 1,

wherein the instructions are further to cause the processor to determine lateral shift parameters for the set of two-dimensional matrices based on a complementarity metric for at least one of the set of two-dimensional matrices, and

wherein the complementarity metric compares a production material placement associated with a given two-dimensional matrix with a production material placement for matrices below the given two-dimensional matrix in the set of two-dimensional matrices.

4. The apparatus according to claim 1, wherein the defined sequence comprises at least one of:

a random walk in the third dimension;

a defined set of lateral shift parameters for each matrix in the set of two-dimensional matrices; and

a set of points on an analytic curve in the third dimension with variation in a first and second dimension.

5. The apparatus according to claim 1, wherein the predefined two-dimensional threshold matrix comprises one of:

a void-and-cluster matrix;

an amplitude modulation (AM) matrix; and

a noise matrix having a predefined color.

6. The apparatus according to claim 1,

wherein the instructions are further to cause the processor to obtain an object property associated with the three-dimensional object and to select the defined sequence based on the obtained object property,

the defined sequence implementing a structure of the three-dimensional object that contributes to the obtained object property.

7. An apparatus to generate control data for production of a three-dimensional object comprising:

a processor; and

a non-transitory storage medium on which is stored instructions that are to cause the processor to;

apply a halftoning operation to a digital representation of at least a portion of the three-dimensional object, wherein the instructions are to cause to the processor to process the digital representation of at least the portion of the three-dimensional object in association with a three-dimensional threshold matrix to output discrete material arrangement instructions for at least one production material;

generate the three-dimensional threshold matrix for use by the halftone generator, wherein to generate the three-dimensional threshold matrix, the instructions are to cause the processor to;

obtain values for a predefined two-dimensional threshold matrix; and

extend the predefined two-dimensional threshold matrix into a third dimension to generate the three-dimensional threshold matrix by laterally-shifting, with respect to the third dimension and according to a defined sequence, at least a subset of the values in subsequent matrices in a set of two-dimensional matrices with respect to the predefined two-dimensional threshold matrix, each matrix in the set of two-dimensional matrices comprising the at least a subset of the values for the predefined two-dimensional threshold matrix,

wherein the instructions are further to cause the processor to determine lateral shift parameters for the set of two-dimensional matrices based on a complementarity metric for at least one of the set of two-dimensional matrices, and

wherein the complementarity metric compares a production material placement associated with a given two-dimensional matrix with a production material placement for matrices below the given two-dimensional matrix in the set of two-dimensional matrices.