Method for determining logical components of a document

• US 7,386,789 B2
• Filed: 02/27/2004
• Issued: 06/10/2008
• Est. Priority Date: 02/27/2004
• Status: Active Grant

• Current Assignee: Hewlett-Packard Development Company, L.P. (HP Inc.)
• Original Assignee: Hewlett-Packard Development Company, L.P. (HP Inc.)
• Inventors: He, Lei, Chao, Hui, Fan, Jian
• Primary Examiner(s): Hong; Stephen
• Assistant Examiner(s): Ludwig; Matthew J
• Application Number:
  US10/787,971
• Publication Number:
  US 20050193327A1
• Time in Patent Office: 1,565 Days
• Field of Search: 715/513, 715/514, 715/531, 715/239, 715/204, 715/234, 715/243, 715/276, 345/619, 707/3
• US Class Current: 715/239
• CPC Class Codes: G06F 40/166 Editing, e.g. inserting or deleting

Abstract

A method for determining logical components of a portable document format (PDF) document is disclosed. The method includes separating the document into a plurality of layers. A PDF document is created for each of the plurality of layers. The method also includes determining a logical structure for each layer. The logical structures of the plurality of layers are combined to determine the logical components of the PDF document.

Claims

1. A method for determining logical components of a portable document format (PDF) document, the method comprising:

separating the PDF document into a plurality of layers based on types of page objects within the PDF document;

creating a separate PDF document for each of the plurality of layers, wherein the separate PDF documents include a separate PDF document for each type of page object within die PDF document;

determining a logical structure for each of said separate PDF documents; and

combining the logical structures from each of said separate PDF documents.

2. The method of claim 1 wherein the plurality of layers comprise a text layer, an image layer and a vector graphics layer.

3. The method of claim 2 wherein the text layer includes characters and words.

4. The method of claim 3 wherein the words have at least one of a horizontal and a vertical orientation and the watt arc grouped according to the orientation.

5. The method of claim 4 further comprising:

forming text lines with words have same attributes, said attributes including font type, size arid color.

6. The method of claim 5 further comprising;

forming text segments with text lines having same attributes.

7. The method of claim 6 further comprising:

creating a bounding box for each text segment.

8. The method of claim 7 wherein the bounding boxes arc polygons.

9. The method of claim 2 further comprising:

determining a rectangle for an image layer, said rectangle being of a minimum size to encompass the image.

10. The method of claim 9 further comprising

converting a graphic object to a bitmap image in the vector graphics layer.

11. The method of claim 10 further comprising:

identifying at least one zone within said bitmap image.

12. The method of claim 11 further comprising:

determining an outline, the outline surrounding said zone.

13. The method of claim 12 wherein the outline is a polygon.

14. The method of claim 13 wherein path elements within said polygon are expressed as an SVG component.

15. The method of claim 2 wherein the vector graphics layer comprises lines, curves and rectangles forming at least one graphic object.

16. The method of claim 1 wherein the plurality of layers comprise at least two of a text layer, an image layer and a vector graphics layer.

17. The method of claim 16 wherein the plurality of layers comprise identical layers.

18. The method of claim 1 further comprising:

preserving the order of the layers.

19. A system including a computer processing unit for determining logical components of a portable document format (PDF) document comprising:

means for separating the PDF document into a plurality of layers based on types of page objects within the PDF document;

means for creating a separate PDF document for each of said plurality of layers, wherein the separate PDF documents include a separate PDF document for each type of page object within the PDF document;

means for determining a logical structure for each of said separate PDF documents; and

means for combining the logical structures of said separate PDF documents.

20. A computer readable medium containing executable instructions, when executed in a processing system, cause the system to perform a method comprising:

separating a portable document format (PDF) document into a plurality of layers based on types of page objects within the PDF document;

creating a separate PDF document for each of the plurality of layers, wherein the separate PDF documents include a separate PDF document for each type of page object within the PDF document;

determining a logical structure for each of said separate PDF documents; and

combining the logical structures from each of said separate PDF documents.