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| United States Patent |
5,923,792 |
| Shyu , et al. |
July 13, 1999 |
Screen display methods for computer-aided data entry
Abstract
An optical character recognition screen editing process is performed
efficiently and only when necessary. The process is ordered so that editing is
performed in increasing order of work intensity. That is, less "expensive"
(i.e., less time consuming) correction methods are performed first, as a filter
for more "expensive" correction methods. In the preferred embodiment, individual
character are corrected first, information fields are corrected second, and
entire forms are correction last. Preferably, the individual characters may be
collected from a number of forms before being displayed for correction.
| Inventors: |
Shyu; Ing-Shyh (Taipei, TW); Lin;
Wen-Wen (Tainan, TW); Lien; Yao-Nan (Fengyuan, TW); Chen;
Mou-Yen (Taoyuan, TW); Tu; Lo-Ting (Taipei, TW); Huang;
Yea-Shuan (Hsinchu, TW) |
| Assignee: |
Industrial Technology Research Institute
(TW) |
| Appl. No.: |
598080 |
| Filed: |
February 7, 1996 |
| Current U.S. Class: |
382/309 |
| Intern'l Class: |
G06K 009/03 |
| Field of Search: |
382/309,310,311
|
References Cited [Referenced
By]
U.S. Patent Documents
| 4566127 |
Jan., 1986 |
Sekiya et al. |
382/309. |
| 4813077 |
Mar., 1989 |
Woods et al. |
382/311. |
| 5123062 |
Jun., 1992 |
Sangu |
382/57. |
| 5153927 |
Oct., 1992 |
Yamanari et al. |
382/61. |
| 5233672 |
Aug., 1993 |
Yamanari et al. |
382/57. |
| 5235654 |
Aug., 1993 |
Anderson et al. |
382/61. |
| 5251273 |
Oct., 1993 |
Betts et al. |
382/57. |
| 5293429 |
Mar., 1994 |
Pizano et al. |
382/267. |
| 5305396 |
Apr., 1994 |
Betts et al. |
382/36. |
| 5550930 |
Aug., 1996 |
Berman et al. |
382/311. |
Primary
Examiner: Couso; Jose L.
Attorney, Agent or Firm: Proskauer Rose
LLP
Claims
We claim:
1. A method for manually editing a plurality of
optically scanned documents, comprising the steps of:
a. determining if
characters on the optically scanned documents are not recognized;
b.
accumulating a plurality of unrecognized characters from the documents;
c. displaying together the accumulated unrecognized characters;
d. manually editing the unrecognized characters;
e. performing a
first integrity check on:
(1) documents having manually edited
characters; and
(2) documents not having unrecognized characters;
f. performing a field edit on fields from the documents failing the
first integrity check;
g. performing a second integrity check on the
field edited fields; and
h. saving the field edited information if it
passes the second integrity check.
2. The method of claim 1, wherein the
step of determining if characters on the optically scanned document are not
recognized further comprises:
a. classifying an optically scanned
document as one of:
(1) completely recognized;
(2) manual
editing required; and
(3) rejected;
b. saving the document if it
is classified as completely recognized;
c. performing an edit on the
entire document if it is classified as rejected; and
d. performing claim
1, steps b-h on the document if it is classified as manual editing required.
3. The method of claim 1, wherein the step of accumulating a plurality
of unrecognized characters comprises saving in an intermediate file the
unrecognized characters and information identifying the location of the
unrecognized character.
4. The method of claim 1, wherein the step of
manually editing the unrecognized characters further includes the steps of:
a. displaying on a first portion of a monitor the accumulated
unrecognized characters; and
b. providing on a second portion of the
monitor an area for displaying input corrected characters.
5. The method
of claim 4, further comprising displaying on a third portion of the screen
information about the displayed characters.
6. The method of claim 4,
wherein before the step of displaying, selecting one of either only numerals and
only letters for display.
7. The method of claim 4, wherein before the
step of displaying, selecting a character editing screen display set up.
8. The method of claim 7, wherein the step of selecting a character
editing screen display setup further comprises the steps of:
a.
accumulating a number of unrecognized characters;
b. selecting whether
the unrecognized characters are to be displayed at a uniform size;
c. if
the unrecognized characters are not selected to be displayed at a uniform size,
arranging the accumulated characters in size order;
d. if the
unrecognized characters are selected to be displayed at a uniform size:
(1) normalizing the unrecognized character;
(2) determining an
image density of the normalized unrecognized characters; and
(3)
arranging the normalized characters in order of image density;
e.
aligning the unrecognized characters.
9. The method of claim 8, wherein
the step of aligning further comprises the steps of:
a. calculating a
center alignment for each character to be displayed; and
b. determining
the alignment line for each character to be displayed.
10. The method of
claim 1, wherein the step of performing an integrity check further comprises
comparing a field entry with predetermined information to cross-check accuracy
of the entry.
11. The method of claim 1, wherein the step of performing
the integrity check further comprises checking a value range of a field entry to
determine if it satisfies a predetermined relationship.
12. The method
of claim 1, wherein the step of field editing further comprises the steps of:
a. displaying on a first portion of a monitor a rejected field; and
b. providing on a second portion of the monitor an area for displaying
an input corrected character string.
13. The method of claim 12, further
comprising displaying on a third portion of the screen information about the
rejected field.
14. The method of claim 12, further comprising
displaying on a fourth portion of a monitor the rejected field and fields elated
to the rejected field.
15. The method of claim 14, further comprising
indicating characters in the rejected field and related fields that are likely
to be erroneous.
16. The method of claim 1, wherein if the field fails
the second integrity check, the step of field editing further comprises the
steps of:
a. determining if the field is either one of an independent
field and a related field;
b. if the field is an independent field,
highlighting a name of the rejected field;
c. if the field is related,
displaying the rejected field and fields related to it.
17. A method for
displaying a number of unrecognized optically scanned images, comprising the
steps of:
a. accumulating a number of unrecognized characters from a
plurality of documents;
b. selecting if the accumulated unrecognized
characters are to be displayed at a uniform size;
c. if the accumulated
unrecognized characters are not selected to be displayed at a uniform size,
arranging the accumulated characters in size order;
d. if the
accumulated unrecognized characters are selected to be displayed at a uniform
size:
(1) normalizing the unrecognized characters;
(2)
determining an image density of the accumulated unrecognized characters;
(3) arranging the characters in order of image density;
e.
aligning the accumulated unrecognized characters; and
f. displaying the
aligned accumulated unrecognized characters.
18. The method of claim 17,
wherein the step of aligning further comprises the steps of:
a.
calculating a center alignment for each character to be displayed; and
b. determining the alignment line for each character to be displayed.
19. The method of claim 17, further comprising the steps of after
aligning the unrecognized characters:
a. displaying on a first portion
of a monitor the accumulated unrecognized characters; and
b. providing
on a second portion of the monitor an area for displaying input corrected
characters.
20. The method of claim 19, further comprising displaying on
a third portion of the screen information about the displayed characters.
21. The method of claim 17, wherein before the step of accumulating,
selecting one of only numerals and only letters for display.
Description
RELATED APPLICATION
This patent application includes subject
matter related to U.S. patent application Ser. No. 08/489,945, entitled "Optical
Character Recognition System For Forms Having Printed and Handwritten
Characters", filed on Jun. 13, 1995 and invented by Ing-Shyh Shyu, Lo-Ting Tu,
Mou-Yen Chen, Wen-Wen Lin, and Kai-Hsiang Chou. The contents of that application
are incorporated herein by reference.
FIELD OF THE INVENTION
The
present invention is directed to optical character recognition and, more
particularly, to a highly efficient method for manually correcting rejected
characters or character fields.
BACKGROUND OF THE INVENTION
Many
businesses and governmental agencies process a large number of printed forms
which, when completed, contain handwritten entries.
There are a number
of known ways to extract and process the information contained in the
handwritten entries on the forms and to store the information and the forms. For
example, the data may be extracted using known image scanning devices and
optical character recognition technologies to extract either the printed or
handwritten data on the form. An image of the form itself may be stored, for
example, by photographing the document onto microfilm or microfiche, or by
optically scanning the form and storing an electronic image of it on laser disk
or other electronic storage medium. Image scanning devices and optical character
recognition ("OCR") technology are well known and commercially available. An OCR
device improved over these known devices is disclosed in related application
Ser. No. 08/489,945.
FIG. 1 is a block diagram of a typical OCR system
50, such as may be used with the present invention. This system 50 includes a
paper transport system 51. The paper transport system 51 moves the forms in the
direction of the arrow past an optical scanner ("OCR scanner") 52. A preferred
embodiment of the OCR scanner 52 forms a digital image of a form by illuminating
the form with a bright light such as a laser light and then recording the
reflected light using storage devices such as CCDs. This type of scanner may be
used to form a bitonal digital image wherein each pixel is either white or
black, corresponding to logic "1" or logic "0". One such OCR scanner 52 is a
model TDC2610W, manufactured by Terminal Data Corp.
The scanner 52 may
be connected to a processor 54, such as a general purpose computer or a special
purpose hardware processing element. The processor's hardware elements may be
optical processing elements or electronic processing elements such as resistor
summing networks and digital logic circuits. The processor may include a
microprocessor 56 and other components; a screen or monitor 58; and a keyboard
or other input device 60. The processor 54 may also include a memory device 62
for storing the scanned documents. This memory device may be, for example, a
disk memory, a RAM, or other memory device.
The forms to be read are
scanned in the OCR scanner 52. Information on the forms may be provided in
fields (i.e., a "name" field, an "address" field, etc.). Before the forms are
scanned, the processor 54 may already have "learned" the location and expected
content of particular fields. For example, the processor 54 may have "learned"
that a handwritten address is expected at a particular location on a particular
document (see, for example, U.S. patent application Ser. No. 08/489,945). The
image data information is processed in the processor 54. During processing, an
image of the scanned forms and character recognition information may be
displayed on the screen 58.
Character recognition systems, particularly
those which recognize handwritten characters, cannot guarantee a completely
error free recognition. Recognition mistakes inevitably occur. Thus, some manual
editing (i.e., performed by a human editor) is typically needed. In some
conventional systems, character recognition systems often refuse to recognize
characters that are sloppily written or illegible, so that the ratio of
correctly to incorrectly recognized characters increases. This higher
recognition correctness rate makes an automated system more valuable than a
manual data entry system, wherein a human data processor reads a document and
manually types the data. Therefore, it is a desirable characteristic of an
optical character recognition system to provide an efficient method for manually
editing unrecognized or rejected characters, words, or field entries.
Optically recognized documents may be classified into one of the
following three categories:
1. "Correct" or Full Automatic Recognition:
each character on the document is recognized and the document as a whole passes
all integrity checks such as dictionary (i.e., recognized characters form a
known word) and grammar (i.e., recognized words form grammatically correct
phrases or sentences) processing. No additional editing is required and any
recognition mistakes in the document are due to system inherent errors. For a
practical system, the inherent error rate of the system should be lower than
that of a manual entry system.
2. Manual Editing Required: a document
requiring some manual editing. If a number of characters on the document are
rejected (i.e., the character cannot be recognized) or whose recognition results
do not pass integrity checks (i.e., the recognized characters do not form a
recognized word or recognized words do not form a valid phrase or sentence), the
document is manually edited.
3. Rejected Document: a document rejected
by the recognition system. A rejection could be caused, for example, by a poor
quality scanned image, form error, or sloppy handwriting. The data on a rejected
document must be entirely manually processed.
OCR devices typically
include a screen editing fiction which displays rejected documents on a computer
screen and allows an editor to input corrections. Generally, an image of the
entire form, or a large portion (or "block") of the entire form, containing a
rejected character is displayed on the screen so that the data entry operator
need not refer to the original (hard copy) document. This method is satisfactory
for processing a relatively small number of documents. Where a large number of
documents--i.e., millions of strokes (characters) requiring dozens of data entry
operators--this method is not efficient because each rejected document is
displayed on the screen, regardless of the number of rejected characters in the
document. Thus, even if a single character is rejected in a document, the entire
document appears on the screen. This results in a bottleneck that slows down the
entire OCR process.
Optical character recognition systems have addressed
some of these problems. For example, U.S. Pat. No. 5,251,273 to Betts et al.
discloses a data processing system and method for sequentially correcting
character recognition errors for scanned images of document forms. The device
disclosed in this reference has three recognition coded data correction
processors. These correction processors are (1) an artificial intelligence
processor, (2) a database error processor, and (3) a manual verification and
correction processor. A machine-generated data structure records recognition
results and correction histories and transfers these to each consecutive
processor. After the artificial intelligence and database error correction
processes are complete, field data segments may be displayed on a workstation
for manual correction.
U.S. Pat. No. 5,305,396 to Betts et al. discloses
a data processing system and method for selecting customized character
recognition processes and coded data correction processes for scanned images of
document forms. This reference discloses entering a document form processing
template. The template includes customized system operation parameters which the
data processing system reads before a completed form may be recognized.
U.S. Pat. No. 5,235,654 to Anderson et al. is directed to an advanced
data capture architecture data processing system and method for scanned images
of document forms. This reference discloses a system for generating new document
forms for automatic processing.
U.S. Pat. No. 5,153,927 to Yamanari
discloses a character reading system and method which allows a user to prepare a
user specific processing program without knowing all of the specifications of
the processing program. This reference discloses two processing sections, a
standard processing section and a user defined processing section. The
user-defined processing section allows the user to arbitrarily set a field which
the user wants to check without affecting the standard processing section.
U.S. Pat. No. 5,233,627 to Yamanari et al. is directed to a character
reader and recognizer with a specialized editing function. This reference
discloses a character reader device which avoids a situation where the image
data displayed on a workstation screen overlaps an area for displaying a
particular image containing a rejected character.
U.S. Pat. No.
5,123,062 to Sangu discloses a screen display layout of an entire scanned
document image and displays the recognition results obtained during the
recognition process.
It is an object of the present invention to provide
an efficient method of performing OCR screen editing.
It is another
object of the present invention to provide an OCR screen editing method that has
an easily understood screen layout.
It is yet a further object of the
present invention to provide a screen editing method where only portions of a
form may be displayed for editing.
It is yet an even further object of
the present invention to provide a method for simultaneously screen editing a
number of scanned documents.
SUMMARY OF THE INVENTION
A
preferred embodiment provides an optical character recognition screen editing
process, wherein manual editing is performed efficiently and only when
necessary. The process is ordered so that editing is performed in increasing
order of work intensity. That is, less "expensive" (i.e., less time consuming)
correction methods are performed first, as a filter for more "expensive"
correction methods. In the preferred embodiment, individual characters are
corrected first, information fields are corrected second, and entire forms are
corrected last. Preferably, the individual characters may be collected from a
number of forms before being displayed for correction.
After a document
is scanned and recognized, it may be classified as correct (no editing needed),
manual editing required, or rejected. The correct documents are stored. Rejected
documents are individually edited. The rejected characters (i.e., letters,
numbers, kana characters, kanji characters, etc.) from one or more documents
needing manual editing are collected and displayed on a computer monitor for
correction. In a preferred embodiment, these characters may be arranged in size
or image density (darkness) order and then aligned to appear centered. Arranging
and aligning the characters makes the collection of rejected characters
displayed on the screen look less confusing and is easier for the editor to
understand.
After the characters are corrected, fields of the scanned
documents are checked for integrity--for example, a zip code entry may be
compared with the corresponding town entry to make sure they match, or a
mathematical equation may be checked for accuracy. If a field does not pass the
integrity check, it is displayed on the screen for editing and an editor may
input a corrected character string. The field may again be checked for
integrity. If it fails more than once, the field is displayed with field
information highlighted, or with related fields (i.e., a zip code and a town, or
all numbers in a mathematical equation).
Once all of the fields in a
document are correct, it may be stored in a database. If the document cannot
pass the character correction or field correction processes, it is rejected, and
the entire form is displayed for correction. If the document still cannot be
corrected, it is rejected.
BRIEF DESCRIPTION OF THE DRAWINGS
These and other features of the present invention will become apparent
from the following detailed description, in conjunction with the following
drawings, wherein:
FIG. 1 is a block diagram of the components for an
OCR device;
FIG. 2 is a flow chart of a screen editing process according
to the present invention;
FIG. 3 is a flow chart of a character editing
screen display method according to the present invention;
FIG. 4 is an
illustrative screen display layout during character editing;
FIG. 5 is
an exemplary character editing screen display;
FIG. 6 is an exemplary
character editing screen display with the rejected characters arranged by size
and aligned;
FIG. 7 is a flow chart of a preferred field editing method
according to the present invention;
FIG. 8 is an illustrative screen
display layout during field editing;
FIG. 9 is an exemplary field
editing screen display; and
FIG. 10 is an exemplary field editing screen
display showing related fields and indicating a possible error location.
DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT
Overview of the
Inventive Method
FIG. 2 is a flow chart of a preferred screen editing
method 100 according to the present invention. The scanned document is placed on
a paper transport system 51 and moved past an optical scanner 52. The scanned
image is presented to the processor 54 (step 102). The document is recognized
and converted into an intermediate file (an optical image undergoing
verification) and is classified as one of a "correct" (or "full automatic
recognition"), "manual editing required", or "rejected" document (step 104). If
there are no unrecognized characters and each field satisfies the integrity test
(described in more detail below), the document is classified as "correct". The
correct, fully recognized document requires no further processing and is saved
in a data bank (step 122).
Documents having unrecognized characters or
rejected fields are classified as "manual editing required". Characters, as used
here, is broadly defined. Characters may be, for example, arabic numerals,
alphabetic letters, kana characters, kanji characters, etc. If some characters
are unrecognized (step 106), the unrecognized characters are presented to a
manual editor (e.g., a person) to perform character editing (step 108).
Documents (1) requiring manual editing, but that had no unrecognized characters;
and (2) character edited documents, are processed to determine if they pass the
integrity checks, which check for correct entries in fields (step 110). If the
document fails the integrity checks, field editing is performed (step 114).
Field edited documents are processed to determine if every field passes
the integrity checks (form recognition) (step 116). If every field in a form
passes the integrity checks, it is saved in the data bank (step 122). Documents
failing form recognition (e.g., the characters were not properly read by the OCR
device due to poor quality--sloppily or lightly written, etc.--characters, input
errors, or the like) and "rejected" field edited documents have form editing
performed (step 118). If form editing is required, all of the data on the form
is input manually.
If the form edited document is acceptable (e.g., the
human editor can correct the errors), an image of the document is saved on the
databank (step 122); otherwise, the form is rejected (step 124). The data and
optical image stored in the databank may be, for example, stored, searched,
sorted, or otherwise used.
Character Editing
To perform
character editing, a monitor 58 displays characters which were not recognized
and thus caused a rejection. The displayed characters need not be from the same
document. That is, the unrecognized characters displayed on the monitor may be
from several documents (for example, a batch of scanned documents), not just a
single document. (See FIG. 2, steps 106, 108.) This allows the character
correction process to be performed for many documents simultaneously, resulting
in a more efficient process. The editor may use a keyboard 60 to manually
replace these unreadable characters or incorrectly read characters with correct
characters.
After a predetermined number (a "batch") of forms are
scanned, the image of each unrecognized character in each of the "manual" forms
is stored in a file, for example, in the processor memory 62. Preferably, the
image is stored with an identifier, such as a document and address identifier so
that the location of the rejected character on the particular document may be
located. Rejected characters are displayed on the monitor 58.
After the
character recognition process is complete, unrecognized characters are corrected
by manual editing. A character may be unrecognized for many reason. Typically an
unrecognized character is either written too large or too small on the document,
the quality is poor (i.e., the strokes are broken or clustered), or more than
one character is being treated as a single character. A preferred embodiment of
the invention displays on the screen 58 a list of characters which cannot be
recognized. The on-screen display should be configured to reduce the effects of
the poor quality characters as much as possible to provide the manual editor
with as understandable a display as possible, thus permitting an efficient
editing process. To reduce the effects of poor quality characters, the present
invention preferably: (1) arranges character images on a center alignment
principle; (2) arranges character images on a size basis, i.e., from small to
large or from large to small; (3) arranged in order of increasing or decreasing
darkness; and/or (4) displays letters at one time and numbers at another. This
fourth item avoids confusion between, for example, number 0 and letters O or D.
FIG. 3 is a flow chart of a preferred character editing screen display
method 200. A batch of documents are scanned. A first document image is reviewed
(step 202). To avoid confusion, either images located where alphabetic
characters are expected to be located or numerals are expected to be located are
processed at one time (i.e., avoiding confusion between number 0 and letters O
and D) (step 203). If all characters are recognized (step 204), the next
document image is reviewed (step 206). If characters are not recognized (step
204), the images of the unrecognized characters are accumulated in memory 62,
preferably with identification information, such as the batch and document
number and location of the character on the document. When the number of
accumulated unrecognized characters is equal to the number of characters that
may be displayed on an editing screen (step 210), an image arrangement is
determined.
For example, if the rejected character images are to be
displayed at a uniform size (step 212), then the characters may be normalized
and arranged according to image density (darkness) order. First, the character
images are normalized so that their heights and widths are approximately the
same (step 214). This may be done by using any well known normalization
technique. Then the image density is calculated in a conventional manner (such
as determining the number of black pixels per unit area) (step 216) and the
images are arranged according to the calculated image density (step 218). If the
rejected character images are not to be displayed at a uniform height (step
212), the images may be arranged according to size (step 220). Empirical studies
by the assignee of this invention reveal that human operators more easily
comprehend characters arranged either by image density or size.
After
the characters are arranged according to size and/or image density, the
characters are aligned. First, the alignment center is determined (step 222) by
finding a center point of each character to be displayed. After the center is
determined, the alignment line is determined for each character to be displayed
(step 224). For example, the characters may be aligned based on a horizontal or
vertical center line, or a horizontal bottom line. Then the rejected characters
are displayed on the monitor 58 (step 226). The editor may enter corrected
characters using an input device 60, such as a keyboard or mouse. The process
may be repeated for the other types of characters (e.g., numerals if alphabetic
characters were processed).
FIG. 4 is an illustrative screen display
layout 250 during character editing. The monitor 58 has a screen configuration
250 divided into an upper display area 252, a lower display area 254, and a file
identification area 256. Each of the display areas 252, 254 is further divided
into two sections, an image section 258, 260 and a character section 262, 264.
The image sections 258, 260 display the image of the rejected characters. The
character sections 262, 264 include a space to view the corrected character
input by the editor to be viewed. The file identification area 256 displays
information about the displayed characters, such as the batch number.
FIG. 5 is an exemplary character editing screen display 250'. The upper
display area 252' has an image display section 256' and a character section
260'. The character section 260 has an input line below the displayed rejected
characters. The lower display area 254' also has an image display section 258'
and a character section 262'. The file identification line 264' identifies the
files from which the rejected characters are taken. The cursor 266' is shown.
Each rejected character image is enclosed in a frame 268'; below each frame is a
line 170' to input a corrected character.
FIG. 6 shows the same
character editing screen 250" except that the displayed rejected characters are
arranged by increasing size and aligned by lower boundary of the character
frames (in FIG. 5, the characters are aligned by geometric centers of the
characters). To most viewers, the characters are more readily understood as
arranged in FIG. 6 than as in FIG. 5. Once the characters are corrected, they
are easily redirected to the proper location because the character images are
stored with identification information.
In a preferred embodiment, the
character editing process is performed as follows. A number of documents (i.e.,
a batch) are scanned in the optical scanner 52. A batch comprises a
predetermined number of documents, 500 for example. Thus, a program parameter
FilesPerBatch=500 is used, and the following batch numbers are generated:
______________________________________
Batch Number File Order Number
______________________________________
0 00001-00500
1 00501-01,000
* * * * * *
10 05,001-05,500
* * * * * *
19 09,501-10,000
______________________________________
An editor will enter the batch to be edited--BatchNo. The rejected
characters for part or all of the batch are displayed, as described. The editor
reviews the rejected characters and keys in a corrected character using an
input/output device such as a keyboard or mouse 60. A key definition of a
currently preferred embodiment is:
______________________________________
Data Keys
______________________________________
Normal Letter Letter keys on keyboard
Normal Number Number keys on keyboard
Next Page Command "Enter" or ";"
Unrecognizable Character
Delete With Space Bar
______________________________________
Unrecognizable characters either are unintelligible to the editor,
or contain two or more characters in a single space and cannot be corrected in
that single space. They are deleted with a space bar. The field having the
unrecognizable character will fail the field processing, and the entire field
(not just a single character) may be corrected.
Field Editing
After a document (or documents) has been character edited, the integrity
of the contents of fields are checked to determine if they make "sense". Field
editing may be performed on: (1) documents that had no characters rejected, but
the fully recognized characters in one or more fields did not pass the integrity
checks (see FIG. 2, steps 106, 114); (2) had rejected characters that were
corrected, but having fields that did not pass the integrity checks (see FIG. 2,
steps 110, 114); or (3) having characters that were not corrected (i.e., two
characters were identified by the OCR as a single character). Suitable integrity
checks may be post-word processing and field inspection.
Post word
processing compares field entries with predefined information maintained, for
example, in the processor memory 62 to cross-check the accuracy of the entries.
For example, a word database may contain a number of city, country, road names,
and section numbers for a geographical area. The recognized words may be
compared to the stored words to determine the recognition accuracy. For example,
state, town, and zip code information may be cross-checked to verify the
characters.
A field inspection checks a value range for each character
or determines whether the characters in a field or fields satisfy a
predetermined relationship. For example, if field C is expected to contain the
numerical difference between fields A and B (e.g., C=A-B), a field inspection
may use, for example, the microprocessor 56 to subtract the recognized number in
field B from the recognized number in field A and determine if it equals the
recognized number in field C. If it does not, one or more of fields A, B, and C
may be incorrect. Because the error may have occurred in one or more of these
fields, all three fields may be rejected and require field editing.
To
avoid confusion to the editor, only a single field is displayed at a time or
only a single set of related fields, as described below. After a field is
corrected by an editor, it is again checked for integrity.
FIG. 7 is a
flow chart of a preferred field editing method 300 according to the present
invention. A scanned image is post-word processed or field inspected (step 302),
for example, by the processor 54. If a field on a form passes the integrity
checks (step 304), no field correction is required on this field, and the next
field is processed (steps 320, 322). If the field fails the integrity check
(step 304), field correction is required, and this field is displayed on the
monitor 58 (step 306). If this is the first time the field has been corrected
(step 308), the editor inputs corrected characters to correct the field (step
316) using, for example, an input device 60, such as a keyboard or mouse. The
corrected character string is integrity checked (step 318).
If it is not
the first time the field has been corrected (step 308), it is determined whether
this field is independent or related to other fields (step 310). That is, could
the error in the field be due to an error in another field? If yes, it has
"related" fields; if no, it is an independent field. For example, if the field
is the numerical difference between two numbers (i.e., A-B=C), an error in the
difference may be due to an error in the two numbers to be subtracted or in the
difference. If the field is related to other fields, the field is displayed
along with the related field or fields (step 314). The error location may be
displayed on the screen. For example, if the inputs are: ##EQU1## an error
probably occurred in the third column from the left. The error may have occurred
in any of these fields. Most likely, either the first number or the difference
was improperly entered. The characters in which the error is likely to have
occurred is identified by, for example, changing the background color. Using,
for example, "carries" and "borrows" in simple decimal system mathematics, if
only a single error occurred, it may be easily located. Attached in Appendix A
is pseudocode for a preferred embodiment wherein the error location in the
equation A-B =C is located and the background is highlighted in red. A person
skilled in the art readily recognizes that other types of errors (addition,
multiplication, division, etc.) may also be located in a similar manner.
The previous corrections to the related fields may also be indicated.
This allows the editor to determine that the incorrect result is due to an
improper character string input as a correction, or if the error is due because
a field was corrected, which correction causes an error in another field. If the
field is independent, it is displayed with the field name highlighted (step
312).
After the field is displayed--either highlighted or with the
related fields--corrected character stings are input to correct the field (step
316). The corrected field is again integrity checked (step 318). If it does not
pass, the field is again corrected (steps 308-318). If the field passes (step
318), the form is checked to determine if every field has passed post-word
processing or field inspection (step 320). If every field has not passed the
next field is processed (step 322). If it has, the field editing process is
completed for that document. If all documents in the batch have not been field
checked (step 324), fields from the next document are checked (step 326). If all
documents in the batch have been field checked (Step 324), the field checking
process is complete.
FIG. 8 is an illustrative screen display layout 350
during field editing. In a preferred embodiment of the invention, the monitor 58
may be arranged to have a screen configuration 350 shown in FIG. 8. The screen
350 has a display area 352, a file identification area 354, and a related fields
display area 356. The display area 352 is further divided into two sections, an
image section 358 and a character section 360. The image section 358 displays
the image of the rejected field. The character section 360 includes a space for
the corrected characters to be viewed by the editor. The file identification
area 354 displays information about the displayed fields. The related fields
display area 356 displays related fields that do not pass an integrity check
(such as an incorrect mathematical entry, or an incorrect town/zip code). The
location of the possible error in the fields may be determined mathematically
(see Appendix A) and highlighted or otherwise indicated. In a preferred
embodiment, the possible error location may be identified by a different screen
background or text color.
FIG. 9 is an exemplary character editing
screen display 350' displaying a rejected independent field (e.g., no other
fields are related to the error). The display area 352' has an image display
section 358' and a character section 360'. The file identification line 354'
identifies the file and field from which the rejected characters are taken. A
cursor 362' is shown. The rejected field images are enclosed in a frame 364'.
Below the frame is a number of lines 366' to input a corrected character string.
FIG. 10 is an exemplary character editing screen display 350" displaying
a rejected field having an error related to other fields. The related fields
display area 356" displays each related field and may identify characters in
which the error is likely to be located. The image display section 358" displays
one possibly incorrect field at a time. A field identifier 368' alerts the
editor to which of the rejected fields is being displayed (i.e., here it is
Field "A").
In a preferred embodiment, the field editing process is
performed as follows. A field having an error is displayed on the monitor 58 for
an editor. The editor inputs a corrected character string using an input device
60 such as a keyboard or mouse. After the correction is made, the editor may
request the next field to be corrected. If the corrected field still does not
pass the integrity check, the editor will be informed that the screen will not
advance to the next field. This indication maybe a beep, a message on the screen
and/or other indication. The cursor will return to the first character of the
field. If a number of related fields are rejected, the cursor returns to the
first character of the first field.
A preferred embodiment may use the
following key definitions:
______________________________________
Data Key
______________________________________
Unrecognizable Strings
Enter "9" in the entire field
(e.g., 99999999 . . .)
Illegitimate Strings
Escape Key
Extra Character Delete With Space Bar
______________________________________
An unrecognizable string is an image that cannot be read clearly
and thus cannot be corrected by the editor. These fields are replaced with a
string of 9s. An illegitimate string is an image that can be read clearly, but
which does not make sense in the context of the field. For example, a number in
a field where letters should be found is an illegitimate string.
CONCLUSION
By first correcting the unrecognized characters of
one or more documents, the manual editor performs the least work intensive
process first. That is, individual characters, not fields or entire forms, are
reviewed and corrected. Moreover, performing character correction increases the
likelihood that the character edited forms will pass the field and form
recognition processes. Thus, the manual editing process is performed efficiently
for a number of documents simultaneously.
Arranging rejected characters
in size and/or image density order provides the editor with a neater, easier to
read screen display. This increases efficiency and accuracy. The field editing
determines if a field error may be related to entries in other fields. If so,
these fields are displayed.
The inventive method was tested by several
data entry operators. Several 500 document batches (each document having
approximately 35 characters) were processed by the operators using a prior art
method and the inventive method. Using the prior art method, the data entry
operators processed each batch in an average time of approximately 65 minutes.
Using the inventive method, the data entry operators processed each batch in an
average time of approximately 18 minutes. Thus, the inventive method improves
efficiency approximately 2.6 times above the prior art method.
The
inventors are not aware of any previously known on-screen editing process that
makes efficient use of OCR technology, user operations, and human engineering
principles to provide a coherent and smooth correction process. No previously
known on-screen editing process makes efficient use of electronic computing
power to minimize human labor.
The present invention is not limited to
the disclosed embodiment, but rather various modifications, substitutions, and
structures may be used without departing from the scope of the present
invention.
APPENDIX A
__________________________________________________________________________
File name: GET.sub.-- HINT.C
__________________________________________________________________________
sprintf( buffer, " ");
strcpy( &buffer?10-strlen(A.sub.-- RecogStr) !, A.sub.-- RecogStr );
strcpy( A.sub.-- RecogStr, buffer );
sprintf( buffer, " ");
strcpy( &buffer( 10-strlen(B.sub.-- Recogstr) !, B.sub.-- RecogStr );
strcpy( B.sub.-- RecogStr, buffer );
sprintf( buffer, " ");
strcpy( &buffer?10-strlen(C.sub.-- Recogstr) !, C.sub.-- RecogStr );
strcpy( C.sub.-- RecogStr, buffer );
color = E.sub.-- GREEN;
sprintf( buffer, " A" );
msc.sub.-- draw.sub.-- string( color, Scr.sub.-- CmdHint.left
+ text.sub.-- width, Scr.sub.-- CmdHint.top + text.sub.-- height, buffer
);
sprintf( buffer, " B" );
msc.sub.-- draw.sub.-- string( color, Scr.sub.-- CmdHint.left
+ text.sub.-- width, Scr.sub.-- CmdHint.top + 2*text.sub.-- height,
buffer );
sprintf( buffer, " C" );
msc.sub.-- draw.sub.-- string( color, Scr.sub.-- CmdHint.left
+ text.sub.-- width, Scr.sub.-- CmdHint.top + 3*text.sub.-- height,
buffer );
carry = 0;
for( j = 9; j >= 0; j--) {
av = isdigit(A.sub.-- RecogStr𢽴!) ? A.sub.-- RecogStr𢽴! - `0`: 0;
bv = isdigit(B.sub.-- RecogStr𢽴!) ? B.sub.-- RecogStr𢽴! - `0`: 0;
cv = isdigit(C.sub.-- RecogStr𢽴!) ? C.sub.-- RecogStr𢽴! - `0`: 0;
pass = 0;
if( carry ) {
if( av == 0 ) {
av = 9;
carry = 1;
}
else {
av--;
carry = 0;
}
}
if( av >= bv ) {
if( cv == (av-bv) ) pass=1;
}
else {
if( cv == (10+av-bv) ) pass=1;
carry = 1;
}
color = pass ? E.sub.-- GREEN : E.sub.-- RED
sprintf( buffer, "%c", A.sub.-- RecogStr𢽴! );
msc.sub.-- draw.sub.-- string( color, Scr.sub.-- CmdHint.left
+ (j+3)*text.sub.-- width, Scr.sub.-- CmdHint.top + text.sub.-- height,
buffer );
sprintf( buffer, "%c", B.sub.-- RecogStr𢽴! );
msc.sub.-- draw.sub.-- string( color, Scr.sub.-- CmdRint.left
+ (j+3)*text.sub.-- width, Scr.sub.-- CmdHint.top + 2*text.sub.-- height,
buffer );
sprintf( buffer, "%c", C.sub.-- RecogStr𢽴! );
msc.sub.-- draw.sub.-- string( color, Scr.sub.-- CmdHint.left
+ (j+3)*text.sub.-- width, Scr.sub.-- CmdHint.top + 3*text.sub.-- height,
buffer );
__________________________________________________________________________