초록 ▼

Following scanning of a document image, and optical character recognition (OCR) processing, the outputted OCR text is processed to determine a text format (typeface and font size) to match the OCR text to the originally scanned image. The text format is identified by matching word sizes rather than

Following scanning of a document image, and optical character recognition (OCR) processing, the outputted OCR text is processed to determine a text format (typeface and font size) to match the OCR text to the originally scanned image. The text format is identified by matching word sizes rather than individual character sizes. In particular, for each word and for each of a plurality of candidate typefaces, a scaling factor is calculated to match a typeface rendering of the word to the width of the word in the originally scanned image. After all of the scaling factors have been calculated, a cluster analysis is performed to identify close clusters of scaling factors for a typeface, indicative of a good typeface fit at a constant scaling factor (font size).

대표청구항 ▼

Following scanning of a document image, and optical character recognition (OCR) processing, the outputted OCR text is processed to determine a text format (typeface and font size) to match the OCR text to the originally scanned image. The text format is identified by matching word sizes rather than

Following scanning of a document image, and optical character recognition (OCR) processing, the outputted OCR text is processed to determine a text format (typeface and font size) to match the OCR text to the originally scanned image. The text format is identified by matching word sizes rather than individual character sizes. In particular, for each word and for each of a plurality of candidate typefaces, a scaling factor is calculated to match a typeface rendering of the word to the width of the word in the originally scanned image. After all of the scaling factors have been calculated, a cluster analysis is performed to identify close clusters of scaling factors for a typeface, indicative of a good typeface fit at a constant scaling factor (font size). ning a digital representation of said selected target document, thereby obtaining a digital target document; (c) obtaining a digital representation of said reference document at a predetermined digital resolution, thereby obtaining a digital reference document; (d) selecting a reference region within said digital reference document, said reference region (d1) corresponding to a predetermined portion of said reference document,(d2) having a predetermined location within said digital reference document, and,(d3) containing a plurality of reference pixels therein; (e) selecting a target region of said digital target document, said target region (e1) having a location at least approximately corresponding to said predetermined location within said digital reference document, and,(e2) having a plurality of target pixels contained therein; (f) determining from said reference pixels and said target pixels an offset between said reference region and said target region; (g) performing steps (c) through (f) at least once; (h) calculating an image adjustment rule from any offsets so calculated; (i) applying said image adjustment rule, thereby at least approximately aligning said digital reference document and said selected digital target document; (j) performing steps (c) through (i) at least twice using at least two different digital resolutions; and, (k) determining from said digital target document, said digital reference document, and from any adjustment rules so calculated whether said user-marked document contains a user mark within a predetermined region of said user-marked document. 2. A method according to claim 1, wherein said digital representation of said selected target document is a gray scale image.3. A method according to claim 2, wherein said digital representation of said selected target document is a 4-bit digital gray scale image.4. A method according to claim 1, wherein said digital representation of said selected target document is a digital color image.5. A method according to claim 1, wherein step (a) includes the step of scanning said reference document at a predetermined resolution, thereby obtaining a digital reference image.6. A method according to claim 1, step (h) includes the step of calculating an image adjustment rule using an affine transform.7. A method according to claim 1, step (h) includes the step of calculating an image adjustment rule using a Delaunay triangulation method.8. A method according to claim 1, wherein step (g) includes the step of repeating steps (d) through (f) at least three times.9. A method according to claim 1, wherein step (i) includes the step of applying said image adjustment rule by mathematically relocating said selected digital target document according to said image adjustment rule.10. An apparatus for aligning a user-marked document for use in optical mark recognition according to the method of claim 1, comprising: (a) a computer configurable to access said digital reference document and said digital target document, wherein said computer contains instructions programming said computer to perform said method. 11. An apparatus according to claim 10, further comprising: (b) an electronic scanner, (b1) said scanner being configurable to scan at a plurality of different digital resolutions, and,(b2) said scanner for obtaining digital representations of at least said reference document at a plurality of predetermined digital resolutions, thereby creating digital reference documents at said plurality of predetermined digital resolutions, said digital reference documents being positionable to be made accessible by said computer.12. A device adapted for use by a digital computer wherein a plurality of computer instructions defining the method of claim 1 are encoded, said device being readable by said digital computer, said computer instructions programming said digital computer to perform said method, and, said device being selected from the gro