Segmenting and aligning a plurality of cards in a multi-card image

• US 20070002375A1
• Filed: 06/30/2005
• Published: 01/04/2007
• Est. Priority Date: 06/30/2005
• Status: Abandoned Application

• Current Assignee: Lexmark International Incorporated (Ninestar Corporation)
• Original Assignee: Lexmark International Incorporated (Ninestar Corporation)
• Inventors: Ng, Du-Yong
• Application Number:
  US11/170,949
• Publication Number:
  US 20070002375A1
• Time in Patent Office: Days
• US Class Current: 358/1.180
• CPC Class Codes: G06V 10/24 Aligning, centring, orientation detection or correction of the image
• CPC Class Codes: G06V 30/413 Classification of content, e.g. text, photographs or tables
• CPC Class Codes: H04N 1/3878 Skew detection or correction

Abstract

A method of segmenting and aligning a plurality of cards in a multi-card image, each card of the plurality of cards having at least one object, the multi-card image having a plurality of the objects, includes determining which pixels of the multi-card image are content pixels; grouping together a plurality of the content pixels corresponding to each object of the plurality of the objects to form a cluster corresponding to the each object, the grouping performed for the plurality of the objects to create a plurality of clusters corresponding to the plurality of the objects; determining which clusters of the plurality of clusters should be joined together to form a plurality of superclusters; and forming the plurality of superclusters, each supercluster of the plurality of superclusters corresponding to one card of the plurality of cards.

Claims

1. A method of segmenting and aligning a plurality of cards in a multi-card image, each card of said plurality of cards having at least one object, said multi-card image having a plurality of said objects, the method comprising:

determining which pixels of said multi-card image are content pixels;

grouping together a plurality of said content pixels corresponding to each object of said plurality of said objects to form a cluster corresponding to said each object, said grouping performed for said plurality of said objects to create a plurality of clusters corresponding to said plurality of said objects;

determining which clusters of said plurality of clusters should be joined together to form a plurality of superclusters; and

forming said plurality of superclusters, each supercluster of said plurality of superclusters corresponding to one card of said plurality of cards.

2. The method of claim 1, further comprising downsampling said multi-card image.

3. The method of claim 1, wherein said determining which pixels of said multi-card image are said content pixels includes performing image binarization.

4. The method of claim 1, wherein said determining which said clusters of said plurality of clusters should be joined together includes determining geometric features for each cluster of said plurality of clusters.

5. The method of claim 4, wherein said determining which said clusters should be joined together is based on spatial locations of said each cluster.

6. The method of claim 4, wherein said determining which said clusters of said plurality of clusters should be joined together is based on an assumed minimum separation distance between said cards.

7. The method of claim 4, where said determining which said clusters should be joined together includes testing to determine whether said clusters when joined fit within a predefined envelope.

8. The method of claim 7, further comprising temporarily joining at least two of said clusters of said plurality of clusters to form provisionally combined clusters, wherein said provisionally combined clusters are permanently joined to become at least one of said superclusters if said provisionally combined clusters fit within said predefined envelope, and wherein said provisionally combined clusters are not permanently joined to become said at least one of said superclusters if said provisionally combined clusters do not fit within said predefined envelope.

9. The method of claim 7, further comprising determining skew angles for said clusters as part of said testing to determine whether said clusters when joined fit within said predefined envelope.

10. The method of claim 1, wherein said grouping together said plurality of said content pixels includes:

searching said multi-card image in raster order until a first content pixel is located; and

grouping with said first pixel the neighboring content pixels that are within a predetermined spatial proximity of said first content pixel to form an initial cluster.

11. The method of claim 10, further comprising:

determining which content pixels of said initial cluster are boundary pixels; and

grouping with said initial cluster the neighboring content pixels that are within said predetermined spatial proximity of each boundary pixel of said boundary pixels to form said cluster.

12. The method of claim 1, wherein said multi-card image is a scanned image.

13. The method of claim 1, further comprising determining a spatial relationship between each card of said plurality of cards.

14. The method of claim 13, further comprising aligning said plurality of cards.

15. The method of claim 1, wherein said method is performed without detecting any edges of any of said plurality of cards.

16. The method of claim 1, wherein each card of said plurality of cards includes a boundary region and an interior region, and wherein said method is performed based on using pixels only in said interior region of said each card.

17. An imaging apparatus communicatively coupled to an input source and configured to receive a multi-card image, said imaging apparatus comprising:

a print engine; and

a controller communicatively coupled to said print engine, said controller being configured to execute instructions for segmenting and aligning a plurality of cards in a multi-card image, each card of said plurality of cards having at least one object, said multi-card image having a plurality of said objects, said instructions including;

determining which pixels of said multi-card image are said content pixels;

grouping together a plurality of said content pixels corresponding to each object of said plurality of said objects to form a cluster corresponding to said each object, said grouping performed for said plurality of said objects to create a plurality of clusters corresponding to said plurality of said objects;

determining which clusters of said plurality of clusters should be joined together to form a plurality of superclusters; and

forming said plurality of superclusters, each supercluster of said plurality of superclusters corresponding to one card of said plurality of cards.

18. The imaging apparatus of claim 17, further comprising said controller being configured to execute instructions for downsampling said multi-card image.

19. The imaging apparatus of claim 17, wherein said determining which pixels of said multi-card image are said content pixels includes performing image binarization.

20. The imaging apparatus of claim 17, wherein said determining which said clusters of said plurality of clusters should be joined together includes determining geometric features for each cluster of said plurality of clusters.

21. The imaging apparatus of claim 20, wherein said determining which said clusters should be joined together is based on spatial locations of said each cluster.

22. The imaging apparatus of claim 20, wherein said determining which said clusters of said plurality of clusters should be joined together is based on an assumed minimum separation distance between said cards.

23. The imaging apparatus of claim 20, where said determining which said clusters should be joined together includes testing to determine whether said clusters when joined fit within a predefined envelope.

24. The imaging apparatus of claim 23, further comprising said controller being configured to execute instructions for temporarily joining at least two of said clusters of said plurality of clusters to form provisionally combined clusters, wherein said provisionally combined clusters are permanently joined to become at least one of said superclusters if said provisionally combined clusters fit within said predefined envelope, and wherein said provisionally combined clusters are not permanently joined to become said at least one of said superclusters if said provisionally combined clusters do not fit within said predefined envelope.

25. The imaging apparatus of claim 23, further comprising said controller being configured to execute instructions for determining skew angles for said clusters as part of said testing to determine whether said clusters when joined fit within said predefined envelope.

26. The imaging apparatus of claim 17, wherein said grouping together said plurality of said content pixels includes:

searching said multi-card image in raster order until a first content pixel is located; and

grouping with said first pixel the neighboring content pixels that are within a predetermined spatial proximity of said first content pixel to form an initial cluster.

27. The imaging apparatus of claim 26, further comprising said controller being configured to execute instructions for:

determining which content pixels of said initial cluster are boundary pixels; and

grouping with said initial cluster the neighboring content pixels that are within said predetermined spatial proximity of each boundary pixel of said boundary pixels to form said cluster.

28. The imaging apparatus of claim 17, wherein said multi-card image is a scanned image.

29. The imaging apparatus of claim 17, further comprising said controller being configured to execute instructions for determining a spatial relationship between each card of said plurality of cards.

30. The imaging apparatus of claim 29, further comprising said controller being configured to execute instructions for aligning said plurality of cards.

31. The imaging apparatus of claim 17, wherein said instructions are executed without detecting any edges of any of said plurality of cards.

32. The imaging apparatus of claim 17, wherein each card of said plurality of cards includes a boundary region and an interior region, and wherein said instructions are executed based on using pixels only in said interior region of said each card.

33. The imaging apparatus of claim 17, further comprising a scanner, wherein said input source is said scanner.

34. The imaging apparatus of claim 17, wherein said input source is a scanner.