US6028957A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Image forming apparatus having a noise removing unit
Assignee: Minolta Co Ltd
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Filing: 1997-03-06
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Granted: 2000-02-22
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Expires: 2017-03-06
Abstract
Abstract Pixel data comprising density data of R, G, and B obtained by reading an original with a CCD image sensor are subjected to shading correction by a shading correction unit, and then converted into color region signals H*, V, and C* in the Munsell color space by a first converter. According to the variations of V, a region discriminator determines whether each pixel data belongs to an edge portion of the original image or whether it belongs to a uniform density region of the original image. A noise removing unit performs noise removal by performing smoothing on color region signals H*, V, and C* of the pixel data which have been determined to belong to uniform density regions. A second converter converts the noise-removed color region signals into pixel data of R, G, and B.
Inventors
- 👤 Kentaro Katori
- 👤 Yoshinobu Hada
- 👤 Masahiro Kouzaki
- 👤 Yukihiko Okuno
- 👤 Katsuyuki Hirata
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 20:37
CPC Classifications
G; G06; G06T; G06T5/00; G06T5/20
Claims Analysis
Total Claims: 23
Claim 1
Independent Claim
166 words
An image processing apparatus which corrects color pixel data before printing of the color pixel data, the apparatus comprising: an input unit for receiving pixel data on colors constituting an original image having uniform density regions and edge portions; a first converter for converting said received pixel data into color region signals in a uniform color space; a discriminator for determining whether said color region signals belong to said edge portions or whether said color region signals belong to said uniform density regions; a noise removing unit for receiving said color region signals from said first converter and for removing noise from said color region signals which has been determined to belong to said uniform density regions bv said discriminator; a second converter for converting said noise-removed color region signals into pixel data of each color; and an output unit for outputting said pixel data obtained by said second converter wherein said noise removal is executed for improving color print guality of the pixel image data.
Claim 2
Dependent Claim
166 words
An image processing apparatus which corrects color pixel data before printing of the color pixel data, the apparatus comprising: an input unit for receiving pixel data on colors constituting an original image having uniform density regions and edge portions; a first converter for converting said received pixel data into color region signals in a uniform color space; a discriminator for determining whether said color region signals belong to said edge portions or whether said color region signals belong to said uniform density regions; a noise removing unit for receiving said color region signals from said first converter and for removing noise from said color region signals which has been determined to belong to said uniform density regions bv said discriminator; a second converter for converting said noise-removed color region signals into pixel data of each color; and an output unit for outputting said pixel data obtained by said second converter wherein said noise removal is executed for improving color print guality of the pixel image data.
Claim 3
Dependent Claim
49 words
An image processing apparatus according to claim 1, wherein said pixel data received by said input unit comprises density data of R, G, and B; and said first converter generates color region signals of hue, lightness, and saturation, in accordance with said density data of R, G, and B.
Claim 4
Dependent Claim
17 words
An image processing apparatus according to claim 1, wherein said discriminator performs discrimination using a Laplacian filter.
Claim 5
Dependent Claim
120 words
An image processing apparatus which corrects color pixel data before printing of the color pixel data, the apparatus comprising: an input unit for receiving pixel data on colors constituting an original image; a first converter for converting said received pixel data into color region signals in a uniform color space; a noise removing unit for performing smoothing by using spatial filter to remove noise from said color region signals obtained by said first converter; a second converter for converting said noise-removed color region signals into pixel data of each color; and an output unit for outputting said pixel data obtained by said second converter, wherein said noise removal is executed for improving color print guality of the pixel image data.
Claim 6
Dependent Claim
120 words
An image processing apparatus which corrects color pixel data before printing of the color pixel data, the apparatus comprising: an input unit for receiving pixel data on colors constituting an original image; a first converter for converting said received pixel data into color region signals in a uniform color space; a noise removing unit for performing smoothing by using spatial filter to remove noise from said color region signals obtained by said first converter; a second converter for converting said noise-removed color region signals into pixel data of each color; and an output unit for outputting said pixel data obtained by said second converter, wherein said noise removal is executed for improving color print guality of the pixel image data.
Claim 7
Dependent Claim
37 words
An image processing apparatus according to claim 4, wherein said noise removing unit is provided with a plurality of two-dimensional smoothing filters corresponding to different smoothing conditions, and selects one of said smoothing filters to perform smoothing.
Claim 8
Dependent Claim
59 words
An image processing apparatus according to claim 1, wherein said pixel data received by said input unit comprise density data of R, G, and B; said first discriminator converts said pixel data into color region signals of hue, lightness, and saturation; and said second converter converts said noise-removed color region signals into density data of R, G, and B.
Claim 9
Dependent Claim
179 words
An image processing apparatus which corrects color pixel data before printing of the color pixel data the apparatus comprising: an input unit for receiving pixel data comprising density data of R, G, and B of pixels constituting an original image having uniform density regions and edge portions; a first converter for converting said received pixel data into color region signals in a uniform color space; a discriminator for determining whether said color region signals belong to said edge portions or whether said color region signals belong to said uniform density regions; a noise removing unit for receiving said color region signals from said first converter and for removing noise from said color region signals which has been determined to belong to said uniform density regions by said discriminator; a second converter for converting said noise-removed color region signals into density data of C, M, and Y; and an output for outputting said density data of C, M, and Y obtained by said second converter; wherein said noise removal is executed for improving color print quality of the pixel data.
Claim 10
Dependent Claim
179 words
An image processing apparatus which corrects color pixel data before printing of the color pixel data the apparatus comprising: an input unit for receiving pixel data comprising density data of R, G, and B of pixels constituting an original image having uniform density regions and edge portions; a first converter for converting said received pixel data into color region signals in a uniform color space; a discriminator for determining whether said color region signals belong to said edge portions or whether said color region signals belong to said uniform density regions; a noise removing unit for receiving said color region signals from said first converter and for removing noise from said color region signals which has been determined to belong to said uniform density regions by said discriminator; a second converter for converting said noise-removed color region signals into density data of C, M, and Y; and an output for outputting said density data of C, M, and Y obtained by said second converter; wherein said noise removal is executed for improving color print quality of the pixel data.
Claim 11
Dependent Claim
31 words
An image processing apparatus according to claim 7, wherein said first converter generates color region signals of hue, lightness, and saturation, in accordance with said received pixel data of each color.
Claim 12
Dependent Claim
58 words
An image processing apparatus according to claim 8, wherein said second converter is provided with a table for determining said density data of C, M, and Y, according to said color region signals of hue, lightness, and saturation, and converts said noise-removed color region signals into density data of C, M, and Y in accordance with said table.
Claim 13
Dependent Claim
177 words
An image processing apparatus which corrects color pixel data before printing of the color image data, the apparatus comprising: an input unit for receiving pixel data comprising density data of R, G, and B of pixels constituting an original image; a first converter for converting said received pixel data into color region signals in a uniform color space; a discriminator for determining, by using primary differential filters, whether said color region signals belong to said edge portions or whether said color region signals belong to said uniform density regions; a noise removing unit for receiving said color region signals from said first converter and for removing noise from said color region signals which has been determined to belong to said uniform density regions by said discriminator; a second converter for converting said noise-removed color region signals into density data of C, M, and Y; and an output for outputting said density data of C, M, and Y obtained by said second converter; wherein said noise removal is executed for improving color print quality of the pixel data.
Claim 14
Dependent Claim
177 words
An image processing apparatus which corrects color pixel data before printing of the color image data, the apparatus comprising: an input unit for receiving pixel data comprising density data of R, G, and B of pixels constituting an original image; a first converter for converting said received pixel data into color region signals in a uniform color space; a discriminator for determining, by using primary differential filters, whether said color region signals belong to said edge portions or whether said color region signals belong to said uniform density regions; a noise removing unit for receiving said color region signals from said first converter and for removing noise from said color region signals which has been determined to belong to said uniform density regions by said discriminator; a second converter for converting said noise-removed color region signals into density data of C, M, and Y; and an output for outputting said density data of C, M, and Y obtained by said second converter; wherein said noise removal is executed for improving color print quality of the pixel data.
Claim 15
Dependent Claim
41 words
An image processing apparatus according to claim 7, wherein said noise removing unit performs smoothing on color region signals by moving average with weighting addition to the periphery pixels around a central pixel to remove noise from said color region signals.
Claim 16
Dependent Claim
37 words
An image processing apparatus according to claim 7, wherein said noise removing unit is provided with a plurality of two-dimensional smoothing filters corresponding to different smoothing conditions, and selects one of said smoothing filters to perform smoothing.
Claim 17
Dependent Claim
172 words
An image forming apparatus which corrects color pixel data before image forming operation of the color image data, the apparatus comprising: an input unit for receiving pixel data on colors of pixels constituting an original image having uniform density regions and edge portions; a first converter for converting said received pixel data into color region signals; a discriminator for determining whether said color region signals belong to said edge portions or whether said color region signals belong to said uniform density regions; a noise removing unit for receiving said color region signals from said first converter and for removing noise from said color region signals which has been determined to belong to said uniform density regions by said discriminator; a second converter for converting said noise-removed color region signals into pixel data on colors; and an image forming unit for forming an image according to said pixel data obtained by said second converter; wherein said noise removal is executed for improving quality of the color image formed by said image forming unit.
Claim 18
Dependent Claim
172 words
An image forming apparatus which corrects color pixel data before image forming operation of the color image data, the apparatus comprising: an input unit for receiving pixel data on colors of pixels constituting an original image having uniform density regions and edge portions; a first converter for converting said received pixel data into color region signals; a discriminator for determining whether said color region signals belong to said edge portions or whether said color region signals belong to said uniform density regions; a noise removing unit for receiving said color region signals from said first converter and for removing noise from said color region signals which has been determined to belong to said uniform density regions by said discriminator; a second converter for converting said noise-removed color region signals into pixel data on colors; and an image forming unit for forming an image according to said pixel data obtained by said second converter; wherein said noise removal is executed for improving quality of the color image formed by said image forming unit.
Claim 19
Dependent Claim
152 words
An image processing method for correcting color pixel data before printing of the color pixel data, the method comprising the steps of: (1) receiving pixel data comprising density data on colors of pixels constituting an original image having uniform density regions and edge portions; (2) converting said received pixel data into color region signals; (3) removing noise from said color region signals from said uniform density regions obtained in step (2); (4) converting said noise-removed color region signals into pixel data of said colors; and (5) outputting said pixel data obtained in step (4); wherein said step of removing noise further includes the steps of determining whether each pixel data belongs to an edge portion or whether said pixel data belongs to a uniform density region, and removing noise from each pixel data which has been determined to belong to a uniform density region for improving print quality of the pixel data.
Claim 20
Dependent Claim
152 words
An image processing method for correcting color pixel data before printing of the color pixel data, the method comprising the steps of: (1) receiving pixel data comprising density data on colors of pixels constituting an original image having uniform density regions and edge portions; (2) converting said received pixel data into color region signals; (3) removing noise from said color region signals from said uniform density regions obtained in step (2); (4) converting said noise-removed color region signals into pixel data of said colors; and (5) outputting said pixel data obtained in step (4); wherein said step of removing noise further includes the steps of determining whether each pixel data belongs to an edge portion or whether said pixel data belongs to a uniform density region, and removing noise from each pixel data which has been determined to belong to a uniform density region for improving print quality of the pixel data.
Claim 21
Dependent Claim
32 words
An image processing method according to claim 14, wherein said step of removing noise further includes the step of performing smoothing with one of two-dimensional smoothing filters corresponding to different smoothing conditions.
Claim 22
Dependent Claim
174 words
An image processing method for correcting color pixel data before printing of the color pixel data, the method comprising the steps of: (1) receiving pixel data comprising density data of R, G, and B of pixels constituting an original image having uniform density regions and edge portions; (2) converting said received pixel data into color region signals in a uniform color space; (3) removing color noise from said color region signals from said uniform density regions obtained in step (2); (4) converting said noise-removed color region signals into density data of C, M, and Y; and (5) outputting said density data of C, M, and Y obtained in step (4); wherein said step of removing noise further includes the steps of determining whether each pixel data belongs to an edge portion or whether said pixel data belongs to a uniform density region, and removing noise from each color region signal corresponding to pixel data which has been determined to belong to a uniform density region for improving color print quality of the pixel data.
Claim 23
Dependent Claim
174 words
An image processing method for correcting color pixel data before printing of the color pixel data, the method comprising the steps of: (1) receiving pixel data comprising density data of R, G, and B of pixels constituting an original image having uniform density regions and edge portions; (2) converting said received pixel data into color region signals in a uniform color space; (3) removing color noise from said color region signals from said uniform density regions obtained in step (2); (4) converting said noise-removed color region signals into density data of C, M, and Y; and (5) outputting said density data of C, M, and Y obtained in step (4); wherein said step of removing noise further includes the steps of determining whether each pixel data belongs to an edge portion or whether said pixel data belongs to a uniform density region, and removing noise from each color region signal corresponding to pixel data which has been determined to belong to a uniform density region for improving color print quality of the pixel data.
References Cited (Backward Citations)
US4334244A
Cited
US4878125A
Cited
US5345320A
Cited
US5357353A
Cited
US5398124A
Cited
US5689590A
Cited
US5563726A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2003-02-21 | 2003-08-23 | 2004-02-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2007-02-21 | 2007-08-23 | 2008-02-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2011-02-21 | 2011-08-23 | 2012-02-22 | $7700.00 | Window Closed / Lapsed |