EP0113410A2
Expired / Lapsed
EP
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Image processors
Assignee: International Business Machines Corp
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Filing: 1983-11-15
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Granted: —
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Expires: 2003-11-15
Abstract
Abstract A system is provided which separates line image data from a complex background by analyzing both contrast and shape characteristics of the image data. The system inherently provides image rotations and compression, Image quality monitoring is also provided.
Inventors
- 👤 Gene Dale Rohrer
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-25 09:09
CPC Classifications
H; H04; H04N; H04N1/00; H04N1/40; H04N1/40062; G; G06; G06T; G06T9/00; G06T9/004
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
183 words
An image processor comprising a scanner (14) arranged to scan a target area (16) and to generate a sequence of grey level value signals, one per picture element (pel) over the scanning pattern (12), a buffer (20) connected to the scanner and arranged to retain at least temporarily at least sufficient consecutively generated value signals for the buffer to hold at all processing times a target pel (37), indexed progressively through the scan, together with the signals for those pels (33-36) geographically adjacent and surrounding the target pel forming a window containing the target pel, characterized by first logic (21) for generating difference signals from said buffered value signals representing the net grey level value changes between opposed pairs of boundary pels (33-34, 35-36) of the processing window; second logic (24, 26) for coding a target pel (37, 44) in terms derived from said difference signals indicating significance and value or insignificance; storage means (25, 51) for accumulating the coding, pel by pel; and third logic (27, 73, 80) for processing the stored coding, resulting in a line image of the target area.
Claim 2
Dependent Claim
183 words
An image processor comprising a scanner (14) arranged to scan a target area (16) and to generate a sequence of grey level value signals, one per picture element (pel) over the scanning pattern (12), a buffer (20) connected to the scanner and arranged to retain at least temporarily at least sufficient consecutively generated value signals for the buffer to hold at all processing times a target pel (37), indexed progressively through the scan, together with the signals for those pels (33-36) geographically adjacent and surrounding the target pel forming a window containing the target pel, characterized by first logic (21) for generating difference signals from said buffered value signals representing the net grey level value changes between opposed pairs of boundary pels (33-34, 35-36) of the processing window; second logic (24, 26) for coding a target pel (37, 44) in terms derived from said difference signals indicating significance and value or insignificance; storage means (25, 51) for accumulating the coding, pel by pel; and third logic (27, 73, 80) for processing the stored coding, resulting in a line image of the target area.
Claim 3
Dependent Claim
30 words
An image processor as claimed in claim 1 wherein the second logic generates a tentative coding and the third logic generates a final coding representing an extracted significant line image.
Claim 4
Dependent Claim
129 words
An image processor as claim 1 wherein the second logic incorporates first characterization means (111, Fig. 5) for classifying pels in response to whether the sum (TT) of the absolute values of the difference signals of selected pairs of pels of a group bearing a predetermined adjacency relationship to the current target pel exceeds a threshold value (T), second characterization means (117, Fig. 5) for classifying pels in accordance with the algebraic sign of the two dimensional second derivative of magnitude with respect to distance at the target pel, and means (121) responsive to a predetermined relationship of the classifications of pels by the first and second characterization means for recording selected ones of a limited group of values at corresponding storage locations (45, 46) in the storage (25).
Claim 5
Dependent Claim
24 words
An image processor as claimed in claim 3 wherein the limited group of values comprises four values VI, V2, V3, V4 defined as follows:
Claim 8
Dependent Claim
29 words
An image processor as claimed in claim 3 or 4 including means (136, 137, 142) responsive to the history of generated absolute values for providing said threshold value (T).
Claim 9
Dependent Claim
24 words
An image processor as claimed in claim 3 or 4 including means (129-133) for periodically updating said threshold value as scan lines are processed.
Claim 10
Dependent Claim
40 words
An image processor as claimed in any preceding claim wherein the second logic includes means for changing the resolution of the image such that each pel of the output image corresponds to a plurality of pels of the input image.
Claim 11
Dependent Claim
41 words
An image processor as claimed in any preceding claim wherein the second logic includes means for accumulating the output image in the form of digitally coded words (53, 55) defining a run length number of pels on one of two colours.
Claim 12
Dependent Claim
84 words
An image processor as claimed in any of claims 1 to 7 wherein the scan lines extend in a first direction and wherein successive scan lines form a parallel line raster extending line to line in a second direction that is normal to said first direction, and the second logic accumulates the output image in the form of digitally coded words (53, 55) defining a run length number of picture elements of one of two colours, such run length extending in said second direction.
Claim 13
Dependent Claim
93 words
An image processor as claimed in claim 8 or 9 including a transition store (51), the capacity of which is less than the number of pels comprising a potential line image, the second logic recording a run length of a tentative colour in the transition store by initiating or adding to run lengths accumulated therein, the third logic validating or changing said tentative colour for a run length accumulated in transition store, and means responsive to validation of a complete run length for transferring the validated run length to an output storage (28).
Claim 14
Dependent Claim
27 words
An image processor as claimed in claims 9 and 10 wherein the output storage is attached to a printer for printing image lines in said second direction.
Claim 15
Dependent Claim
36 words
An image processor as claimed in any preceding claim including means responsive to the number of picture elements of an input image having various difference values generated therefor, for producing a signal representative of image quality.
Claim 16
Dependent Claim
42 words
An image processor as claimed in any preceding claim in which the first logic generates two difference values per target pel corresponding to the next adjacent pels in the scanning direction and to the corresponding positions in the next adjacent scan lines.
References Cited (Backward Citations)
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