Patent EP0159880A2 successfully refreshed from Google Patents.
EP0159880A2
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Apparatus for evaluating density and evenness of printed patterns
Assignee: Fujitsu Ltd
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Filing: 1985-04-12
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Granted: —
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Expires: 2005-04-12
Abstract
Abstract Apparatus for evaluating density and evenness of a pattern printed on an article comprises means (4, 5) for calculating the density distribution of a plurality of image data in each segment of the pattern, means (6) for normalising the density distribution with an area of effective image data in each segment, and means (8) for quantifying the density and evenness of the patterns. The density distribution calculating means includes a differential circuit (44) for differentiating the image data in each segment. A first discriminating-converting circuit (45) receives and discriminates the differential values with a predetermined value, and converts the values into a specific value in response to the discrimination. A second discriminating-converting circuit (42) performs the same process for the image data in each segment. A synthesizer circuit (62) finds an effective domain of the printed patterns by synthesizing the output signals from the first and second discriminating-converting circuits. A calculating circuit (5) calculates a density histogram of the image data with reference to the effective domain. The normalising means includes a circuit (6) for deciding which are effective segments, on the basis of the found effective domain. An area calculating circuit calculates the total effective area A of the density histogram of the effective segments and partial effective areas B; of the density histogram. The quantifying means includes a circuit (81) for calculating ratios C; = B i /A representing the density evenness in each effective segment.
Inventors
- 👤 Tohru Ozaki
- 👤 Takashi Toriu
- 👤 Hiromichi Iwase
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-07 07:34
CPC Classifications
G; G06; G06V; G06V10/00; G06V10/40; G06V10/42; G06T; G06T7/00; G06T7/0002; G06T7/40; G06T7/41; G06T2207/00; G06T2207/30; G06T2207/30168
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
63 words
Apparatus for evaluating density and evenness of a pattern printed on an article, characterised by means (4,5) for calculating the density distribution of a plurality of image data in each segment of the pattern; means (6) for normalising the density distribution with an area of effective image data in each segment; and means (8) for quantifying the density and evenness of the patterns.
Claim 2
Dependent Claim
63 words
Apparatus for evaluating density and evenness of a pattern printed on an article, characterised by means (4,5) for calculating the density distribution of a plurality of image data in each segment of the pattern; means (6) for normalising the density distribution with an area of effective image data in each segment; and means (8) for quantifying the density and evenness of the patterns.
Claim 3
Dependent Claim
153 words
Apparatus according to claim 1, characterised in that the density distribution calculating means (4,5) includes a differential circuit (44) for receiving the plurality of image data in each segment and for producing differential values thereof; a first discriminating-converting circuit (45) for receiving the differential values, for discriminating the received differential values with a predetermined value, and for converting the received differential values into a specific value in response to the discrimination; a second discriminating-converting circuit (42) for receiving the plurality of image data in each segment, for discriminating the received image data with a predetermined value, and for converting the received image data into a specific value in response to the discrimination; a circuit (62) for finding an effective domain of the printed patterns by synthesizing signals output from the first and second discriminating-converting circuits; and means (5) for calculating a density histogram of the image data with reference to the effective domain.
Claim 4
Dependent Claim
90 words
Apparatus according to claim 2, characterised in that the normalising means includes means (6) for deciding effective segments on the basis of the found effective domain; means (7) for calculating a total effective area A of the density histogram of the effective segments decided at the effective segment deciding means and partial effective areas B i (i = 1, 2, ..., N) of the density histogram with reference to predetermined values; and means (81) for calculating ratios C . = B i /A representing density evenness in each effective segment.
Claim 5
Dependent Claim
62 words
Apparatus according to claim 3, characterised in that the effective segment deciding means (6) includes cooperative projection data calculation means (61) and synthesizing means (62), the projection data calculation means counting the number of the image data in the effective segment, and the synthesizing means synthesizing adjoining segments on the basis of the projection data counted at the projection data calculation means.
Claim 6
Dependent Claim
68 words
Apparatus according to any one of claims 2-4, characterised in that the density distribution calculating means (4,5) further includes a delay circuit (43), disposed between the second discriminating-converting circuit (42) and the synthesizing circuit (62), for delaying the signal output from the second discriminating-converting circuit a predetermined time to synchronize it with the signal output from the first discriminating-converting circuit (45) at the input of the synthesizing circuit.
Claim 7
Dependent Claim
137 words
Apparatus according to claim 1, characterised in that the density distribution calculating means (4,5) includes a differential circuit (44) for receiving the plurality of image data in each segment and for producing differential values thereof; a discriminating-converting circuit (45) for receiving the differential values, for discriminating the received differential values with a predetermined value, and for converting the received differential values into a specific value in response to the discrimination; a circuit (lla) for extracting a maximum value of the image data placed on adjacent sections to the centre portion; a selector (llb) for receiving the maximum value and the image datum at the centre portion and for outputting either one of the received data in response to the output signal from the discriminating-converting circuit; and means (12) for calculating a density histogram of the image data.
Claim 8
Dependent Claim
91 words
Apparatus according to claim 6, characterised in that the normalizing means includes: means (13) for isolating background data included in the density histogram output from the density histogram calculating means (12); means (14) for calculating a total effective area A of the density histogram the background data of which is isolated by the background isolating means, and partial effective areas B i of the density histogram with reference to a predetermined value; and means (17) for calculating ratios C i = B i /A representing density evenness in the effective segments.
Claim 9
Dependent Claim
60 words
Apparatus according to claim 7, characterised in that the normalizing means further includes a circuit (15), between the area calculating means (14) and the density evenness calculating means (17), for finding effective segments with reference to the respective total area A so as to effect the calculation of the ratio for only effective segments at the density evenness calculating means.
Claim 10
Dependent Claim
84 words
Apparatus according to claim 1, wherein the density distribution calculating means includes a differential circuit (21a) for receiving the plurality of image data in each segment and for producing differential values thereof; a discriminating-selecting circuit (22a) for receiving the differential value and the image data, for comparing the received differential value with a predetermined value, and for outputting either the image data or a constant value in response to the compared output; and means (22) for calculating a density histogram of the image data.
Claim 11
Dependent Claim
90 words
Apparatus according to claim 9, characterised in that the normalizing means includes means (23) for isolating background data included in the density histogram output from the density histogram calculating means (22); means (24) for calculating a total effective area A of the density histogram the background data of which is isolated by the background isolating means, and partial effective areas B i of the density histogram with reference to predetermined values; and means (27) for calculating ratios C . = B i /A representing density evenness in the effective segments.
Claim 12
Dependent Claim
59 words
Apparatus according to claim 10, characterised in that the normalizing means further includes a circuit (25), between the area calculating means and the density evenness calculating means (27), for finding effective segments with reference to the respective total area A so as to effect the calculation of the ratio for only effective segments at the density evenness calculating means.
Claim 13
Dependent Claim
28 words
Apparatus according to claim 1, characterised by means for evaluating the density and evenness of the patterns on the basis of the quantified value at the quantifying means.
Claim 14
Dependent Claim
18 words
Apparatus according to claim 1, characterised by means for grouping the plurality of image data into segment data.
Claim 15
Dependent Claim
21 words
Apparatus according to claim 2, characterised by a memory device for storing the image data into segment areas in the memory.
Claim 16
Dependent Claim
11 words
Apparatus according to any preceding claim, characterised by image input means.
References Cited (Backward Citations)
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