Dual density digital image system

• US 5,153,936 A
• Filed: 07/19/1990
• Issued: 10/06/1992
• Est. Priority Date: 06/27/1988
• Status: Expired due to Fees

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Tsalalikhin, Yakov, Probst, Robert E., Rajagopal, Doraiswamy, Morris, Hugh M., Parks, Carol A., Youngs, Gary L.
• Primary Examiner(s): Harkcom, Gary V.
• Assistant Examiner(s): Nguyen, Phu K.
• Application Number:
  US07/559,526
• Time in Patent Office: 810 Days
• Field of Search: 364/518, 364/521, 340/747, 340/750, 340/731, 382/47, 382/44, 382/56, 395/128, 395/133, 395/162
• US Class Current: 345/428
• CPC Class Codes: G06T 9/00 Image coding bandwidth or redundancy reduction for static pictures H04N1/41; coding or decoding of static colour picture signals H04N1/64; methods or arrangements for coding, decoding, compressing or decompressing digital video signals H04N19/00
• CPC Class Codes: G09G 5/391 Resolution modifying circuits, e.g. variable screen formats
• CPC Class Codes: H04N 1/2179 Interfaces allowing access to a plurality of users, e.g. connection to electronic image libraries
• CPC Class Codes: H04N 1/333 Mode signalling or mode changing; Handshaking therefor
• CPC Class Codes: H04N 1/6011 with simulation on a subsidiary picture reproducer H04N1/622 takes precedence; matching two or more picture reproducers H04N1/6052
• CPC Class Codes: H04N 2201/0081 Image reader H04N2201/0091 - H04N2201/0094 take precedence
• CPC Class Codes: H04N 2201/0082 Image hardcopy reproducer H04N2201/0091 - H04N2201/0094 take precedence
• CPC Class Codes: H04N 2201/0089 Image display device
• CPC Class Codes: H04N 2201/33328 Resolution

Abstract

A data processing system stores and displays digital images, and includes a workstation having a document input scanner for digitizing document images at a first resolution, an image display unit for displaying digitized document images at a second resolution which is less than the first resolution and a printer for printing digitized document images at a third resolution greater than the second resolution. The system reduces communications traffic and assures fast access time on the network since the bulk of the traffic will utilize the smaller compressed data records required for the second resolution. However, these improvements in communication traffic and access time do not sacrifice the availability of high resolution compressed data records occasionally needed for printing and other high resolution operations.

Claims

1. A data processing system for storing and displaying digital images, including a workstation having a document input scanner coupled thereto for digitizing document images at a first resolution, an image display unit coupled thereto for displaying digitized document images at a second resolution which is less than said first resolution, and a printer coupled thereto for printing digitized document images at a third resolution which is greater than said second resolution, said workstation coupled to an image host computer, comprising:

a memory in said workstation, having an input coupled to said document scanner for receiving a digitized document image at said first resolution;

an image compression means coupled to said memory and having an output coupled to said image host computer, for compressing said first resolution digitized document image and outputting a first compressed image record to said image host computer for storage;

a first image storage means coupled to said image host computer for storing compressed records of images digitized at said first resolution, said image host computer storing said first compressed image record in said first image storage means;

a resolution modification means having an input coupled to said memory, for reducing the resolution of said first resolution digitized document image to said second resolution and outputting a second resolution digitized document image;

said memory having an input coupled to said resolution modification means, for receiving said second resolution digitized document image;

the image display unit having an input coupled to said memory, for receiving said second resolution digitized document image for display;

said image compression unit compressing said second resolution digitized document image and outputting a second compressed image record to said image host computer for storage, said second compressed image record being smaller in size than said first compressed image record;

a second image storage means coupled to said image host computer for storing compressed records of images digitized at said second resolution, said image host computer storing said second compressed image record in said second image storage means;

said host selectively accessing said first image storage means in response to a print command;

said image compression means including an image decompression means having an input coupled to said image host computer, for receiving and decompressing said first compressed image record from said first image storage means to restore said first resolution digitized document image in response to said print command;

the printer coupled to an output of said image decompression means for printing digitized document images at said third resolution;

said host selectively accessing said second image storage means in response to a display command;

said image decompression means receiving from said host computer and decompressing said second compressed image record from said second image storage means to restore said second resolution digitized document image in response to said display command;

said memory receiving from said decompression means said second resolution digitized document image for display on said image display unit.

2. The system of claim 1, which further comprises:

a third image storage means coupled to said image host computer for storing compressed records of images digitized at said first resolution;

said image host computer transferring said first compressed image record from said first image storage means to said third image storage means after a predetermined period.

3. The system of claim 2, which further comprises:

said image host computer selectively accessing said said first compressed image record from said first image storage means before the expiration of said predetermined period;

said image host computer selectively accessing said said first compressed image record from said third image storage means after the expiration of said predetermined period.

4. The system of claim 1, which further comprises:

a third image storage means coupled to said image host computer for storing compressed records of images digitized at said first resolution;

said image host computer transferring said first compressed image record from said first image storage means to said third image storage means after a predetermined period;

said image host computer discarding said second compressed image record from said second image storage means after said predetermined period.

5. The system of claim 4, which further comprises:

said image host computer selectively accessing said said first compressed image record from said third image storage means after the expiration of said predetermined period;

said image decompression means coupled to said image host computer, receiving and decompressing said first compressed image record from said first image storage means to restore said first resolution digitized document image;

said resolution modification means coupled to said image decompression means, for reducing the resolution of said first resolution digitized document image to said second resolution and outputting a second resolution digitized document image;

said image display unit having an input coupled to said resolution modification means, for receiving said second resolution digitized document image for display.

6. A data processing system for storing and displaying digital images, including a workstation having a document input scanner coupled thereto for digitizing document images at a first resolution, an image display unit coupled thereto for displaying digitized document images at a second resolution which is less than said first resolution and a printer coupled thereto for printing digitized document images at a third resolution greater than said second resolution, said workstation coupled to an image host computer, comprising:

a higher resolution bit plane memory in said workstation, having an input coupled to said document scanner for receiving a digitized document image at said first resolution;

a higher resolution image compression unit coupled to said higher resolution bit plane memory and having an output coupled to said image host computer, for compressing said first resolution digitized document image and outputting a first compressed image record to said image host computer for storage;

a first image storage means coupled to said image host computer for storing compressed records of images digitized at said first resolution, said image host computer storing said first compressed image record in said first image storage means;

a resolution modification means having an input coupled to said higher resolution bit plane memory, for reducing the resolution of said first resolution digitized document image to said second resolution and outputting a second resolution digitized document image;

a lower resolution bit plane memory in said workstation, having an input coupled to said resolution modification means, for receiving said second resolution digitized document image;

said image display unit having an input coupled to said lower resolution bit plane memory, for receiving said second resolution digitized document image for display;

a lower resolution image compression unit coupled to said lower resolution bit plane memory and having an output coupled to said image host computer, for compressing said second resolution digitized document image and outputting a second compressed image record to said image host computer for storage, said second compressed image record being smaller in storing capacity than said first compressed image record;

a second image storage means coupled to said image host computer for storing compressed records of images digitized at said second resolution, said image host computer storing said second compressed image record in said second image storage means;

a higher resolution image decompression means having an input coupled to said image host computer, for receiving and decompressing said first compressed image record from said first image storage means to restore said first resolution digitized document image;

an image scaling means having an input coupled to said higher resolution image decompression means, for converting said first resolution digitized document image into a third resolution digitized document image having said third resolution;

said printer having an input coupled to said image scaling means, for receiving said third resolution digitized document image for printing;

a lower resolution image decompression means having an input coupled to said image host computer, for receiving and decompressing said second compressed image record from said second image storage means to restore said second resolution digitized document image;

said lower resolution bit plane memory having an input coupled to said lower resolution image decompression means, for receiving said second resolution digitized document image for display on said image display unit.

7. A workstation for use in a data processing system or storing and displaying digital images, comprising:

a higher resolution bit plane memory in said workstation, having an input coupled to a document scanner for receiving a digitized document image at a first resolution;

a higher resolution image compression unit coupled to said higher resolution bit plane memory and having an output coupled to an image host computer, for compressing said first resolution digitized document image and outputting a first compressed image record to an image host computer for storage;

a resolution modification means having an input coupled to said higher resolution bit plane memory, for reducing the resolution of said first resolution digitized document image to a second resolution and outputting a second resolution digitized document image;

a lower resolution bit plane memory in said workstation, having an input coupled to said resolution modification means, for receiving said second resolution digitized document image;

an image display unit having an input coupled to said lower resolution bit plane memory, for receiving said second resolution digitized document image for display;

a lower resolution image compression unit coupled to said lower resolution bit plane memory and having an output coupled to said image host computer, for compressing said second resolution digitized document image and outputting a second compressed image record to said image host computer for storage, said second compressed image record being smaller in size than said first compressed image record;

a higher resolution image decompression means having an input coupled to said image host computer, for receiving and decompressing said first compressed image record from a first image storage means to restore said first resolution digitized document image;

an image scaling means having an input coupled to said higher resolution image decompression means, for converting said first resolution digitized document image into a third resolution digitized document image having a third resolution;

a lower resolution image decompression means having an input coupled to said image host computer, for receiving and decompressing said second compressing image record from a second image storage means to restore said second resolution digitized document image;

said lower resolution bit plane memory having an input coupled to said lower resolution image decompression means, for receiving said second resolution digitized document image for display on said image display unit.

8. The method of claim 7, which further comprises:

receiving and decompressing said first compressed image record from said first image storage means to restore said first resolution digitized document image;

printing digitized document images at substantially said first resolution.

9. The method of claim 8, which further comprises:

receiving and decompressing said second compressed image record from said second image storage means to restore said second resolution digitized document image;

receiving said second resolution digitized document image for display on said image display unit.

10. The method of claim 9, which further comprises:

transferring said first compressed image record from said first image storage means to a third image storage means after a predetermined period;

discarding said second compressed image record from said second image storage means after said predetermined period.

11. The method of claim 10, which further comprises:

receiving and decompressing said second compressed image record from said second image storage means before the expiration of said predetermined period, to restore said second resolution digitized document image;

receiving said second resolution digitized document image for display on said image display unit.

12. The method of claim 11, which further comprises:

selectively accessing said said first compressed image record from said third image storage means after the expiration of said predetermined period;

receiving and decompressing said first compressed image record from said first image storage means to restore said first resolution digitized document image;

reducing the resolution of said first resolution digitized document image to said second resolution and outputting a second resolution digitized document image;

receiving said second resolution digitized document image for display.

13. A data processing system for inputting, storing, displaying and printing digital images of documents, including a workstation and a host data processor connected thereto, said system comprising:

a document scanner, for inputting a first digitized image of a document at a first pel per inch resolution represented by a first data set;

a resolution modification means coupled to an output of said scanner, for converting said first digitized image to a second digitized image at a second pel per inch resolution less than said first resolution, said second image represented by a second data set which has less information than said first data set;

a data compression means coupled to an output of said scanner and coupled to an output of said resolution modification means, for receiving said first data set from said scanner representing said first image and removing redundant data therefrom forming a compressed first data set having a first plurality of binary digits representing said first image, and receiving said second data set from said modification means representing said second image and removing redundant data therefrom forming a compressed second data set, having a second plurality of binary digits representing said second image, said second plurality being less than said first plurality;

an image display coupled to an output of said modification means, for receiving said second data set and displaying said second image at said second resolution;

a communications adapter coupled to an output of said compression means, for transmitting both said compressed first data set and said compressed second data set over a communications link to said host;

a first bulk storage coupled to said host, for storing said compressed first data set;

a second bulk storage coupled to said host, for storing said compressed second data set;

a command input device coupled to an input of said adapter, for inputting a first request for printing a hard copy of said document which is transmitted over said link to said host;

said host accessing said first bulk storage to fetch said compressed first data set which is transmitted to said adapter over said link in response to said first request;

a data decompression means coupled to an output of said adapter and having an output coupled to a printing means, for receiving said compressed first data set from said adapter and restoring redundant data thereto forming said first data set which is output to said printing means to print a hard copy, in response to said first request;

said command input device inputting a second request for displaying an image of said document on said display which is transmitted over said link to said host;

said host accessing said second bulk storage device to fetch said compressed second data set which is transmitted to said adapter over said link in response to said second request;

said decompression means coupled to said display, for receiving said compressed second data set from said adapter and restoring redundant data thereto forming said second data set which is output to said display, in response to said second request.

14. The system of claim 13 which further comprises:

a third bulk storage coupled to said host, for storing said first compressed data set;

said host transferring said first compressed data set from said first bulk storage to said third bulk storage after a predetermined period following the storage of said compressed first data set on said first bulk storage;

said host selectively accessing said compressed first data set from said first bulk storage before the expiration of said predetermined period;

said host data processor selectively accessing said compressed first data set from said third bulk storage after the expiration of said predetermined period.