Image processing system with on-the-fly JPEG compression

• US 5,619,594 A
• Filed: 07/27/1995
• Issued: 04/08/1997
• Est. Priority Date: 04/15/1994
• Status: Expired due to Fees

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Melen, Roger D.
• Primary Examiner(s): Couso, Yon J.
• Application Number:
  US08/507,866
• Time in Patent Office: 621 Days
• Field of Search: 382/312, 382/233, 382/232, 382/248, 382/249, 382/250, 382/305, 358/426, 358/403, 395/114, 395/115
• US Class Current: 382/233
• 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: G06T 7/70 Determining position or orientation of objects or cameras camera calibration G06T7/80
• CPC Class Codes: G06T 9/007 Transform coding, e.g. discrete cosine transform
• 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 30/40 Document-oriented image-based pattern recognition
• CPC Class Codes: H04N 1/00326 with a data reading, recognizing or recording apparatus, e.g. with a bar-code apparatus arrangements for the associated working of recording or reproducing apparatus with related apparatus G11B31/00
• CPC Class Codes: H04N 1/00331 with an apparatus performing optical character recognition character recognition G06V30/10
• CPC Class Codes: H04N 1/32101 Display, printing, storage or transmission of additional information, e.g. ID code, date and time or title
• CPC Class Codes: H04N 2201/3225 of data relating to an image, a page or a document
• CPC Class Codes: H04N 2201/3266 of text or character information, e.g. text accompanying an image H04N2201/3226 takes precedence

Abstract

A personal imaging computer system includes an on-the-fly compression processor which operates in coordination with a document scanner to compress document image information as the document is being scanned. Once the document has been scanned and compressed, the personal imaging computer system operates to determine the identity of characters on the scanned-in document by decompressing the compressed image, processing the decompressed image so as to identify characters in the image, and by storing a text file which contains the identity of the characters so-determined. Preferably, the text file is stored in association with the compressed image so that the image may be retrieved in response to a text-based search of plural such text files.

Claims

1. A personal imaging computer system which scans in documents and determines the identity of printed characters on the scanned-in documents, said system comprising:

a scanner for scanning in lines of the document so as to form lines of gray-scale document information;

an on-the-fly compression processor which operates in coordination with the scanner to compress, using lossy compression, the lines of gray-scale document information so as to form a compressed document image which includes compressed printed character images;

decompression means for decompressing the compressed document image and the compressed printed character images in the compressed document image so as to form a decompressed gray-scale document image which includes gray-scale printed character images containing artifacts due to lossy compression by said compression processor and decompression by said decompression means;

optical-character-recognition-processing means for gray-scale OCR identification of the artifacted gray-scale printed character images in the decompressed gray-scale document image so as to obtain computerized character codes which correspond to the printed characters; and

storing means for storing the compressed document image in association with a text file containing the character codes determined by said optical-character-recognition-processing means.

2. A system according to claim 1, wherein said compression processor is switchably operable in at least two modes, a compression mode and a decompression mode.

3. A system according to claim 2, further comprising means for switching said compression processor to the decompression mode and means for feeding a compressed image file to said compression processor, whereby said compression processor outputs decompressed bit map pixel data.

4. A system according to claim 3, further comprising output means for outputting the decompressed bit map pixel data.

5. A system according to claim 4, wherein said output means includes thresholding means for converting gray-scale pixel data to binary pixel data.

6. A system according to claim 1, wherein the text file is stored in association with the compressed image so as to form part of a database of retrievable compressed images.

7. A system according to claim 6, further comprising means for performing a text-based search of stored text files and for retrieving compressed image files associated with text files that match the search query.

8. A system according to claim 7, wherein the compression processor is operable in two modes, a compression mode and a decompression mode, and wherein compressed image files retrieved by said retrieval means to the compression processor and the compression processor is switched to its decompression mode, whereby compressed image files are decompressed to bit map pixel data.

17. A personal imaging computer system according to claim 1, wherein said on-the-fly compression processor performs JPEG lossy compression.

9. A personal imaging computer system which scans in documents and determines the identity of printed characters on the scanned-in documents, said system comprising:

a scanner for scanning in lines of the document so as to form lines of gray-scale document information;

an on-the-fly compression processor which operates in coordination with the scanner to compress, using lossy compression, the lines of gray-scale document information so as to form a compressed document image which includes compressed printed character images;

a memory for storing the compressed document image and for storing process steps for processing the compressed document image; and

a processor for executing the stored process steps;

wherein the process steps stored in said memory include process steps to (a) decompress the compressed document image and the compressed printed character images in the compressed document image so as to form a decompressed gray-scale image which includes gray-scale printed character images containing artifacts due to lossy compression by said compression processor and subsequent decompression, (b) optical-character recognition process the gray-scale printed character images in the decompressed gray-scale image so as to obtain computerized character codes which correspond to the printed characters, and (c) store in a memory a text file containing the identity of the character codes so obtained.

10. A system according to claim 9, wherein said compression processor is switchably operable in at least two modes, a compression mode and a decompression mode.

11. A system according to claim 10, further comprising means for switching said compression processor to the decompression mode and means for feeding a compressed image file to said compression processor, whereby said compression processor outputs decompressed bit map pixel data.

12. A system according to claim 11, further comprising output means for outputting the decompressed bit map pixel data.

13. A system according to claim 12, wherein said output means includes thresholding means for converting gray-scale pixel data to binary pixel data.

14. A system according to claim 9, wherein the text file is stored in association with the compressed image so as to form part of a database of retrievable compressed images.

15. A system according to claim 14, further comprising means for performing a text-based search of stored text files and for retrieving compressed image files associated with text files that match the search query.

16. A system according to claim 15, wherein the compression processor is operable in two modes, a compression mode and a decompression mode, and wherein compressed image files retrieved by said retrieval means to the compression processor and the compression processor is switched to its decompression mode, whereby compressed image files are decompressed to bit map pixel data.

18. A personal imaging computer system according to claim 9, wherein said on-the-fly compression processor performs JPEG lossy compression.

19. A personal imaging computer system which scans in documents and determines the identity of printed characters on the scanned-in documents, said system comprising:

a scanner interface which collects gray-scale document information from a scanner which scans in the document;

a compression processor which performs lossy compression on the gray-scale document information so as to form a compressed document image which includes compressed printed character images;

a decompresser which decompresses the compressed document image and the compressed printed character images in the compressed document image so as to form a decompressed gray-scale document image which includes gray-scale printed character images containing artifacts due to lossy compression by said compression processor and decompression by said decompresser;

an optical-character-recognition processor which processes the artifacted gray-scale printed character images in the decompressed gray-scale document image so as to obtain computerized character codes which correspond to the printed characters; and

a memory which stores the compressed document image in association with a text file containing the character codes obtained by said recognition processor.

20. A personal imaging computer system according to claim 19, wherein the compression processor performs JPEG lossy compression.

21. A personal imaging computer system according to claim 19, wherein said compression processor operates in coordination with the scanner so as to provide on-the-fly compression as the document is being scanned.

22. A personal imaging computer system according to claim 19, wherein said compression processor is switchably operable in at least two modes, a compression mode and a decompression mode.

23. A personal imaging computer system according to claim 22, further comprising means for switching said compression-processor to the decompression mode and means for feeding a compressed image file to said compression processor, whereby said compression processor outputs decompressed bit map pixel data.

24. A personal imaging computer system according to claim 23, further comprising output means for outputting the decompressed bit map pixel data.

25. A personal imaging computer system according to claim 24, wherein said output means includes thresholding means for converting gray-scale pixel data to binary pixel data.

26. A personal imaging computer system according to claim 19, wherein the text file is stored in association with the compressed image so as to form part of a database of retrievable compressed images.

27. A personal imaging computer system according to claim 26, further comprising means for performing a text-based search of stored text files and for retrieving compressed image files associated with text files that match the search query.

28. A personal imaging computer system according to claim 27, wherein the compression processor is operable in two modes, a compression mode and a decompression mode, and wherein compressed image files retrieved by said retrieval means to the compression processor and the compression processor is switched to its decompression mode, whereby compressed image files are decompressed to bit map pixel data.