Reduced resolution document storage and retrieval system

• US 5,867,277 A
• Filed: 07/18/1996
• Issued: 02/02/1999
• Est. Priority Date: 04/15/1994
• Status: Expired due to Term

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Garland, Harry T., Melen, Roger D.
• Primary Examiner(s): Wong, Peter S.
• Assistant Examiner(s): TOATLEY, GREGORY J
• Application Number:
  US08/683,139
• Time in Patent Office: 929 Days
• Field of Search: 358/296, 358/298, 358/297, 382/56, 382/15, 382/14, 382/47, 382/305, 382/306, 382/309, 382/310, 382/321, 381/1, 364/419.9, 345/17
• US Class Current: 358/296
• CPC Class Codes: G06F 16/40 of multimedia data, e.g. slideshows comprising image and additional audio data retrieval of still image data G06F16/50; retrieval of audio data G06F16/60; retrieval of video data G06F16/70
• CPC Class Codes: G06F 16/5846 using extracted text
• CPC Class Codes: G06F 16/5854 using shape and object relationship
• CPC Class Codes: G06V 30/10 Character recognition
• CPC Class Codes: G06V 30/155 Removing patterns interfering with the pattern to be recognised, such as ruled lines or underlines
• CPC Class Codes: G06V 30/162 Quantising the image signal

Abstract

A personal imaging computer system, which is connectable to and operable with a computerized local or wide area network, identifies characters in a document on which the characters are formed. The system scans the document to obtain a gray-scale image of the document, generates a binary image from the gray-scale image by comparing the gray-scale image with the threshold, segments the binary image to locate individual characters within the binary image and to determine the shape of the individual characters, extracts gray-scale image information from the gray-scale image for each such individual character based on the location and shape of the character in the binary image, recognition-processes the extracted gray scale image information to determine the identity of the character, and stores the identity of the character. The character identities are stored in a character file in association with the image so as to facilitate image retrieval with a text-based search over many such character files. Preferably, the image is not stored in its scanned-in resolution, but rather is stored at a reduced resolution so as to reduce memory storage requirements.

Claims

1. A document storage and retrieval apparatus comprising:

means for obtaining a gray-scale image of a document at a first resolution, the first resolution being suitable for optical-recognition-processing text in the document;

optical-recognition-processing means for optically recognizing text in the gray-scale image and for obtaining a computer-readable file of character codes for the text;

reducing means for reducing resolution of the gray-scale image to a second resolution which is low relative to the first resolution, the second resolution being suitable for visual perception and reproduction of the gray-scale image; and

storing means for storing the reduced resolution gray-scale image in association with the computer-readable text file such that the reduced resolution gray-scale image may be retrieved based on a search of the text file.

2. An apparatus according to claim 1, wherein said storing means stores the reduced resolution gray-scale image and the computer-readable text file on a computerized local area network.

3. An apparatus according to claim 1, further comprising searching means for searching plural computer-readable text files based on a search query, first retrieving means for retrieving computer-readable text files that match the search query, and second retrieving means for retrieving reduced resolution gray-scale images that said storing means stored in association with the retrieved computer-readable text files.

4. An apparatus according to claim 3, wherein said storing means stores the reduced resolution gray-scale image in compressed form, and further comprising decompressing means for decompressing the retrieved reduced-resolution gray-scale images prior to display or print.

5. An apparatus according to claim 3, further comprising displaying means for displaying retrieved reduced-resolution gray-scale images.

6. An apparatus according to claim 3, further comprising printing means for printing retrieved reduced-resolution gray-scale images.

7. An apparatus according to claim 3, wherein the computer-readable text files and the reduced-resolution gray-scale images are retrieved from a computerized local area network.

8. An apparatus according to claim 1, wherein said reducing means lowers image resolution such that the reduced-resolution gray-scale image preserves color and gray-scale content of the original image.

9. An apparatus according to claim 1, wherein said means for obtaining comprises scanning means for scanning the document so as to form a gray-scale image of the document.

10. An apparatus according to claim 1, wherein said means for obtaining comprises means for retrieving the gray-scale image of the document from a computer image file.

11. A document storage and retrieval apparatus comprising:

a memory for storing a gray-scale image of a document at a first resolution, the first resolution being suitable for optical-recognition-processing text in the document, said memory also for storing instruction sequences by which the gray-scale image is processed; and

a processor for executing the stored instruction sequences;

wherein the stored instruction sequences include process steps adapted to cause said processor to (a) optical-recognition-process text in the gray-scale image so as to obtain a computer-readable file of character codes for the text, (b) reduce resolution of the gray-scale image to a second resolution which is low relative to the first resolution, the second resolution being suitable for visual perception and reproduction of the gray-scale image, and (c) store the reduced resolution gray-scale image in association with the computer-readable text file such that the reduced resolution gray-scale image may be retrieved based on a search of the text file.

12. An apparatus according to claim 11, wherein the reduced resolution gray-scale image and the computer-readable text file are stored on a computerized local area network.

13. An apparatus method according to claim 11, wherein said stored instruction sequences further includes process steps to (i) search plural computer-readable text files based on a search query, (ii) retrieve computer-readable text files that match the search query, and (iii) retrieve reduced resolution gray-scale images that were stored in association with the retrieved computer-readable text files.

14. An apparatus according to claim 13, wherein the reduced resolution gray-scale image is stored in compressed form, and wherein said stored instruction sequences further include a process step to decompress the retrieved reduced-resolution gray-scale images prior to display or print.

15. An apparatus according to claim 13, wherein said stored instruction sequences further include process steps to display retrieved reduced-resolution gray-scale images.

16. An apparatus according to claim 13, wherein said stored instruction sequences further includes process steps to print retrieved reduced-resolution gray-scale images.

17. An apparatus according to claim 13, wherein the computer-readable text files and the reduced-resolution gray-scale images are retrieved from a computerized local area network.

18. A method according to claim 11, wherein image resolution is lowered such that the reduced-resolution gray-scale image preserves color and gray-scale content of the original image.

19. An apparatus according to claim 11, further comprising a scanner for scanning the document so as to form a gray-scale image of the document.

20. An apparatus according to claim 11, further comprising a disk memory from which a computer image file having the gray-scale image of the document is retrieved.

21. A document storage and retrieval method comprising the steps of:

obtaining a gray-scale image of a document at a first resolution, the first resolution being suitable for optical-recognition-processing;

optically recognizing text in the gray-scale image so as to obtain a computer-readable file of character codes for the text;

reducing resolution of the gray-scale image to a second resolution which is low relative to the first resolution, the second resolution being suitable for visual perception and reproduction of the gray-scale image; and

storing the reduced resolution gray-scale image in association with the computer-readable text file such that the reduced resolution gray-scale image may be retrieved based on a search of the text file.

22. A method according to claim 21, wherein in said storing step, the reduced resolution gray-scale image and the computer-readable text file are stored on a computerized local area network.

23. A method according to claim 21, further comprising the steps of searching plural computer-readable text files based on a search query, retrieving computer-readable text files that match the search query, and retrieving reduced resolution gray-scale images that said storing step stored in association with the retrieved computer-readable text files.

24. A method according to claim 23, wherein in said storing step the reduced resolution gray-scale image is stored in compressed form, and further comprising the step of decompressing the retrieved reduced-resolution images prior to display or print.

25. A method according to claim 23, further comprising the step of displaying retrieved reduced-resolution gray-scale images.

26. A method according to claim 23, further comprising the step of printing retrieved reduced-resolution gray-scale images.

27. A method according to claim 23, wherein the computer-readable text files and the reduced-resolution gray-scale images are retrieved from a computerized local area network.

28. A method according to claim 21, wherein in said reducing step, image resolution is lowered such that the reduced-resolution gray-scale image preserves color and gray-scale content of the original image.

29. A method according to claim 21, wherein said obtaining step comprises scanning the document so as to form a gray-scale image of the document.

30. A method according to claim 21, wherein said obtaining step comprises retrieving the gray-scale image of the document from a computer image file.

31. Computer-executable process steps which store and retrieve documents and which are stored on a computer readable-medium, the process steps including:

an obtaining step to obtain a gray-scale image of a document at a first resolution, the first resolution being suitable for optical-recognition-processing;

an optical-recognition-processing step to optically recognize text in the gray-scale image so as to obtain a computer-readable file of character codes for the text;

a reducing step to reduce resolution of the gray-scale image to a second resolution which is low relative to the first resolution, the second resolution being suitable for visual perception and reproduction of the gray-scale image; and

a storing step to store the reduced resolution gray-scale image in association with the computer-readable text file such that the reduced resolution gray-scale image may be retrieved based on a search of the text file.

32. Computer-executable process steps according to claim 31, wherein in said storing step, the reduced resolution gray-scale image and the computer-readable text file are stored on a computerized local area network.

33. Computer-executable process steps according to claim 31, further comprising a searching step to search plural computer-readable text files based on a search query, a first retrieving step to retrieve computer-readable text files that match the search query, and a second retrieving step to retrieve reduced resolution gray-scale images that were stored by said storing step in association with the retrieved computer-readable text files.

34. Computer-executable process steps according to claim 33, wherein in said storing step the reduced resolution gray-scale image is stored in compressed form, and further comprising a decompressing step to decompress the retrieved reduced-resolution gray-scale images prior to display or print.

35. Computer-executable process steps according to claim 33, further comprising a displaying step to display retrieved reduced-resolution gray-scale images.

36. Computer-executable process steps according to claim 33, further comprising a printing step to print retrieved reduced-resolution gray-scale images.

37. Computer-executable process steps according to claim 33, wherein the computer-readable text files and the reduced-resolution gray-scale images are retrieved from a computerized local area network.

38. Computer-executable process steps according to claim 31, wherein in said reducing step, image resolution is lowered such that the reduced-resolution gray-scale image preserves color and gray-scale content of the original image.

39. Computer-executable process steps according to claim 31, wherein said obtaining step comprises a scanning step to scan the document so as to form a gray-scale image of the document.

40. Computer-executable process steps according to claim 31, wherein said obtaining step comprises a retrieving step to retrieve the gray-scale image of the document from a computer image file.