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US5684897A Expired / Lapsed US ⏱️ 0.0 years remaining

Method for quantizing color image data by minimizing least squares error of binary coding

Assignee: YOZAN BUILDING
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Filing: 1995-08-04
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Granted: 1997-11-04
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Expires: 2015-08-04
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Abstract

Abstract A method of condensing color image data in an image processing system so as to simplify operations while reducing errors in the condensation. The method includes, by computer, generating electrical signals corresponding to color image data representative of a physical image; associating an electrical signal corresponding to a representative code with portions of the signals representative of data in the color image data corresponding to each of the pixels; grouping together electrical signals representative of pixels having identical representative codes to form at least one group; assigning to the representative code for each of the at least one group a condensed pixel representable by the representative code for that group; and setting an electrical signal portion corresponding to each pixel in that group equal to an electrical signal representative of a pixel corresponding to the condensed pixel.

Inventors

  • 👤 Ryohei Kumagai
  • 👤 Zi Quan Hong

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-09 11:02
CPC Classifications
H; H04; H04N; H04N1/00; H04N1/46; H04N1/64; H04N1/644

Claims Analysis

Total Claims: 4
Claim 1
Independent Claim 285 words
A method for processing signals representative of color image data representative of a physical image comprising a plurality of pixels, said method comprising the steps of, by computer: generating electrical signals corresponding to color image data representative of said physical image, said electrical signals representing, for each of said pixels, values of each of three primary colors for said pixel, each of said values having upper bits and lower bits of predetermined lengths; defining as color data said upper bits of said signals; defining representative color codes for said image, said codes consisting of said color data sequentially concatenated; grouping together said electrical signals representative of said pixels in said plurality of pixels having identical representative color codes to form at least one color group; determining a representative code having a red component, a green component and a blue component for each said at least one group as follows: ##EQU6## where R rep ,k is the red component of said representative color of the k-th group, G rep ,k is the green component of said representative color of the k-th group, B rep ,k is the blue component of said representative color of the k-th group, R k ,i is a red component of the i-th color in the k-th group, G k ,i is a green component of the i-th color in the k-th group, B k ,i is a blue component of the i-th color in the k-th group, and P(C k ,i) is the number of pixels included in the i-th color of the k-th color group, and where the representative code for the k-th color group is formed by concatenating the red, green and blue components of the k-th color group.
Claim 2
Independent Claim 285 words
A method for processing signals representative of color image data representative of a physical image comprising a plurality of pixels, said method comprising the steps of, by computer: generating electrical signals corresponding to color image data representative of said physical image, said electrical signals representing, for each of said pixels, values of each of three primary colors for said pixel, each of said values having upper bits and lower bits of predetermined lengths; defining as color data said upper bits of said signals; defining representative color codes for said image, said codes consisting of said color data sequentially concatenated; grouping together said electrical signals representative of said pixels in said plurality of pixels having identical representative color codes to form at least one color group; determining a representative code having a red component, a green component and a blue component for each said at least one group as follows: ##EQU6## where R rep ,k is the red component of said representative color of the k-th group, G rep ,k is the green component of said representative color of the k-th group, B rep ,k is the blue component of said representative color of the k-th group, R k ,i is a red component of the i-th color in the k-th group, G k ,i is a green component of the i-th color in the k-th group, B k ,i is a blue component of the i-th color in the k-th group, and P(C k ,i) is the number of pixels included in the i-th color of the k-th color group, and where the representative code for the k-th color group is formed by concatenating the red, green and blue components of the k-th color group.
Claim 3
Dependent Claim 69 words
The method of claim 1, further comprising the steps of: determining whether a color corresponding to the k-th representative code is present in said k-th group; when said color determined not to be present in said k-th group, finding a color of maximal number of pixels in said k-th group; and substituting for said representative color code a color code of said color of said maximal number of pixels.
Claim 4
Dependent Claim 40 words
The method of claim 1, wherein the value of each primary color for each of said pixel values is represented by an eight-bit binary number, or which seven bits comprise said upper bits and one bit comprises said lower bits.

References Cited (Backward Citations)

US4907075A Cited
US5049986A Cited
US5047842A Cited
US5222154A Cited
JPH05242234A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 2000-11-03 2001-05-05 2001-11-04 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 2004-11-03 2005-05-05 2005-11-04 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2008-11-03 2009-05-05 2009-11-04 $7700.00 Window Closed / Lapsed

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