US4827330A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Automatic document image revision
Assignee: Pitney Bowes Docsense Inc
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Filing: 1987-07-20
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Granted: 1989-05-02
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Expires: 2007-07-20
Abstract
Abstract A system for electronically storing revisions or modifications to documents which are already electronically stored in unrevised or unmodified form. The system compares, at the pixel-by-pixel level, a modified document bit map with a stored document bit map and determines from the differences between the two bit maps, at the pixel-by-pixel level, which differences are significant and which are insignificant. A revised document bit map is then formed from the portions of the stored-document bit map exhibiting no significant bit map differences and the significant differences bit map. The result is a revised document bit map in which no unnecessary changes have been introduced into the initial stored-document bit map. The system also includes steps for defining, on a pixel-by-pixel basis, a significant region bit map from the significant difference bit map and for forming the revised document bit map using the significant region bit map.
Inventors
- 👤 John M. Walsh
- 👤 David M. Ott
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 00:21
CPC Classifications
H; H04; H04N; H04N1/00; H04N1/40; H04N1/40093
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
168 words
In a system for electronically capturing and storing images of documents in which stored documents are represented by bit maps identifying black and white pixels of the images, a method of storing modifications to a document having a representative bit map already stored in the system, comprising the steps of: forming a binary modified-document bit map representing a modification of a binary stored document bit map; comparing, pixel-by-pixel, said modified-document bit map with the stored document bit map to determine differences between said stored-document bit map and said modified-document bit map; determining, pixel-by-pixel, which of said differences are significant and which are insignificant; storing in a memory a significant-difference bit map representing the significant differences between said stored document bit map and said modified document bit map; and forming a revised document bit map composed of portions of the stored document bit map containing no significant bit map differences together with said significant-difference bit map, whereby said insignificant bit map differences are excluded from said revised-document bit map.
Claim 2
Dependent Claim
168 words
In a system for electronically capturing and storing images of documents in which stored documents are represented by bit maps identifying black and white pixels of the images, a method of storing modifications to a document having a representative bit map already stored in the system, comprising the steps of: forming a binary modified-document bit map representing a modification of a binary stored document bit map; comparing, pixel-by-pixel, said modified-document bit map with the stored document bit map to determine differences between said stored-document bit map and said modified-document bit map; determining, pixel-by-pixel, which of said differences are significant and which are insignificant; storing in a memory a significant-difference bit map representing the significant differences between said stored document bit map and said modified document bit map; and forming a revised document bit map composed of portions of the stored document bit map containing no significant bit map differences together with said significant-difference bit map, whereby said insignificant bit map differences are excluded from said revised-document bit map.
Claim 3
Dependent Claim
32 words
The method of claim 1, further comprising the steps of: defining, pixel-by-pixel, a change-region bit map from said significant-difference bit map; and forming said revised-document bit map with said change-region bit map.
Claim 4
Dependent Claim
64 words
The method of claim 1, further comprising the step of: forming an additions bit map and a deletions bit map for recording said differences between said stored document and modified-document bit maps, said additions and deletions bit maps identifying pixels in said modified-document bit map which have changed, respectively, from white to black and from black to white compared with said stored-document bit map.
Claim 5
Dependent Claim
35 words
The method of claim 3, further comprising the steps of: identifying as insignificant the pixels of said additions and deletions bit maps which are located adjacently to like colored pixels of said stored-document bit map.
Claim 6
Dependent Claim
61 words
The method of claim 4, further comprising the steps of: deleting said insignificant pixels from said additions and deletions bit maps to form stripped-additions and stripped-deletions bit maps; and selectively causing said stripped-additions and stripped-deletions bit maps to be modified so as to selectively connect pixels of said stripped-additions and stripped-deletions bit maps with colored pixels of said stored-document bit map.
Claim 7
Dependent Claim
47 words
The method of claim 1, wherein said modifications comprise entries made on a standard form document, further comprising the step of storing a stored-form bit map representing said standard form document with no entries thereon, and wherein said stored-document bit map consists of said stored-form bit map.
Claim 8
Dependent Claim
25 words
The method of claim 2, further comprising the steps of: selectively causing said significant-difference bit map to be modified to define a change-region bit map.
Claim 9
Dependent Claim
59 words
The method of claim 2, wherein said step of forming said revised-document bit map further comprises the steps of: copying pixels of said stored-document bit map which correspond to a first logic value of said change region bit map; and copying pixels of said modified-document bit map which correspond to a second logic value of said change-region bit map.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1992-05-01 | 1992-10-31 | 1993-05-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-05-01 | 1996-10-31 | 1997-05-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-05-01 | 2000-10-31 | 2001-05-02 | $7700.00 | Window Closed / Lapsed |