Granted Patent B2

US 12,620,252 · App. 18/179,635 · Granted May 5, 2026

Inventors: Sanjay Krishnan (Hinsdale, IL); David Wong (Los Gatos, CA); Chad Voss (Seattle, WA); Troy Batterberry (Kirkland, WA); Clayton Huthwaite (Chesterfield, VA); Colin Saunders (San Francisco, CA); Stephen Bianamara (Seattle, WA); Parker Beck (Kenmore, WA)

Assignee: EchoMark, Inc.

G06V30/418G06V10/751

Abstract

Claims (56)

1 . A system comprising:

at least one processor; and

one or more computer storage media storing computer-readable instructions thereon that when executed by the at least one processor cause the at least one processor to perform operations comprising:

receiving an artifact derived from a unique copy of an original document;

identifying artifact keypoints within the artifact, the artifact keypoints being identified for features that are reproduced between the artifact and the unique copy;

matching the artifact keypoints to unique copy keypoints within the unique copy;

comparing a first pixel region of the unique copy with a second pixel region of the artifact, the second pixel region of the artifact being located within an area of the artifact that corresponds to the first pixel region in the unique copy, the second pixel region of the artifact being determined from matching the artifact keypoints to the unique copy keypoints; and

outputting an indication that the artifact was derived from the unique copy based on comparing the pixels of the first pixel region with the pixels of the second pixel region.

2 . The system of claim 1 , wherein identifying artifact keypoints comprises:

identifying corner locations formed by content within the artifact; and

associating the identified corner locations of the artifact as the artifact keypoints.

3 . The system of claim 1 , wherein matching the artifact keypoints to the unique copy keypoints comprises:

identifying pixel neighborhoods comprising pixels surrounding the artifact keypoints and the unique copy keypoints; and

vectorizing a feature of the pixels in the pixel neighborhoods, wherein the artifact keypoints are matched to the unique copy keypoints based on a vector distance between feature vectors of the pixels within the pixel neighborhoods of the artifact keypoints and feature vectors of the pixels within the pixel neighborhoods of the unique copy keypoints.

4 . The system of claim 3 , wherein the vectorized feature comprises a pixel intensity gradient.

5 . The system of claim 1 , further comprising performing a rigid transformation to limit an orientation of the artifact relative to the unique copy, wherein the matching is based on the rigid transformation.

6 . The system of claim 1 , wherein the unique copy is included as part of a set of unique copies derived from the original document, and the operations further comprise:

selecting a subset of unique copies from the set of unique copies based on matching the artifact keypoints to the unique copy keypoints;

comparing pixel regions of each unique copy in the subset with corresponding pixel regions of the artifact; and

selecting the unique copy from the unique copies within the subset based on comparing the first pixel region with the second pixel region, wherein the indication is output in response to selecting the unique copy.

7 . The system of claim 1 , wherein the first pixel region of the unique copy is identified by a bounding box of an area in the unique copy comprising a perturbation made from the original document.

8 . A method performed by one or more processors, the method comprising:

generating a set of unique copies of an original document;

identifying unique copy keypoints in the unique copies of the set of unique copies;

identifying pixel regions of pixels within the unique copies, the pixel regions comprising perturbations made from the original document;

determining an artifact is derived from a unique copy of the set of unique copies based on artifact keypoints matching the unique copy keypoints of the unique copy and a comparison of a first pixel region of the unique copy to a second pixel region of the artifact, the second pixel region of the artifact corresponding in location to the first pixel region in the unique copy, wherein the artifact keypoints correspond to features that are reproduced between the artifact and the unique copy; and

outputting an indication that the artifact is derived from the unique copy.

9 . The method of claim 8 , wherein identifying unique copy keypoints comprises:

identifying corner locations formed by content within the unique copies; and

associating the identified corner locations of the unique copies as the unique copy keypoints.

10 . The method of claim 8 , further comprising:

identifying pixel neighborhoods comprising pixels surrounding the unique copy keypoints and the artifact keypoints;

vectorizing a feature of the pixels in the pixel neighborhoods; and

matching the artifact keypoints to the unique copy keypoints based on a vector distance between feature vectors of the pixels within the pixel neighborhoods of the artifact keypoints and feature vectors of the pixels within the pixel neighborhoods of the unique copy keypoints.

11 . The method of claim 10 , wherein the vectorized feature comprises a pixel intensity gradient.

12 . The method of claim 10 , further comprising performing a rigid transformation to limit an orientation of the artifact relative to the unique copy, wherein the matching is based on the rigid transformation.

13 . The method of claim 10 , further comprising:

selecting a subset of unique copies from the set of unique copies based on matching the artifact keypoints to the unique copy keypoints;

comparing pixel regions of each unique copy in the subset with pixel regions of the artifact; and

selecting the unique copy from the unique copies within the subset based on comparing the first pixel region with the second pixel region, wherein the indication is output in response to selecting the unique copy.

14 . The method of claim 8 , wherein the first pixel region of the unique copy is identified by a bounding box of an area in the unique copy comprising a perturbation made from the original document.

15 . One or more computer storage media storing computer readable instructions thereon that, when executed by a processor, cause the processor to perform a method comprising:

matching artifact keypoints to unique copy keypoints, the artifact keypoints identified in an artifact derived from a unique copy of an original document, the artifact keypoints corresponding to features that are reproduced between the artifact and the unique copy, the unique copy keypoints identified in the unique copy;

identifying a first pixel region of pixels in the unique copy, the first pixel region comprising a perturbation made from the original document;

identifying a second pixel region of pixels in the artifact, the second pixel region identified based on the pixels of the second pixel region having a location within the artifact that corresponds to the first pixel region of the unique copy based on matching the artifact keypoints to the unique copy keypoints; and

outputting an indication that the artifact was derived from the unique copy based on the first pixel region compared to the second pixel region.

16 . The media of claim 15 , further comprising identifying the artifact keypoints and the unique copy keypoints, the artifact keypoints and the unique copy keypoints identified by:

identifying corner locations formed by content within the unique copy and the artifact;

associating the identified corner locations of the artifact as the artifact keypoints; and

associating the identified corner locations of the unique copy as the unique copy keypoints.

17 . The media of claim 15 , wherein matching the artifact keypoints to the unique copy keypoints comprises:

identifying pixel neighborhoods comprising pixels surrounding the artifact keypoints and the unique copy keypoints; and

vectorizing a feature of the pixels in the pixel neighborhoods, wherein the artifact keypoints are matched to the unique copy keypoints based on a vector distance between feature vectors of the pixels within the pixel neighborhoods of the artifact keypoints and feature vectors of the pixels within the pixel neighborhoods of the unique copy keypoints.

18 . The media of claim 17 , wherein the vectorized feature comprises a pixel intensity gradient.

19 . The media of claim 15 , further comprising performing a rigid transformation to limit an orientation of the artifact relative to the unique copy, wherein the matching is based on the rigid transformation.

20 . The media of claim 15 , wherein the first pixel region of the unique copy is identified by a bounding box of an area in the unique copy comprising the perturbation made from the original document.

Assignments (1)

Continuity (1)

References Cited (102)