§
Luxuse
Patent Intelligence
Sign In
← Back to Patent Explorer
EP0724356A2 Expired / Lapsed EP ⏱️ 0.0 years remaining

An improved method and system for forming multi-level halftone images from an input digital image

Assignee: Eastman Kodak Co
•
Filing: 1996-01-11
•
Granted: —
•
Expires: 2016-01-11
📄 Original PDF 🌐 Google Patents 🔄 Sync Now

Abstract

Abstract A method for forming a multi-level halftone image from an input digital image having a plurality of pixels so that visibility of halftone patterns is minimized; comprises the steps of transforming input pixel values which represent the tone level of each pixel into modified pixel values which are approximately linear with perceived lightness; applying a multi-level halftoning process to the modified pixel values to produce halftone pixel values having a reduced number of tone levels which are uniformly distributed with respect to the modified pixel values; and transforming the halftone pixel values into output pixel values for permitting an output device to display the digital image so that visibility of halftone patterns is minimized.

Inventors

  • 👤 Kevin E. c/o Eastman Kodak Company Spaulding
  • 👤 Rodney L. C/O Eastman Kodak Company Miller

Bibliographic Details

Application Number —
Jurisdiction EP
Data Source google_patents
Last Synchronized 2026-11-09 11:04
CPC Classifications
H; H04; H04N; H04N1/00; H04N1/40; H04N1/40087

Claims Analysis

Total Claims: 10
Claim 1
Independent Claim 117 words
A method for forming a multi-level halftone image from an input digital image having a plurality of pixels so that visibility of halftone patterns is minimized, comprising the steps of: (a) transforming input pixel values which represent the tone level of each pixel into modified pixel values which are approximately linear with perceived lightness; (b) applying a multi-level halftoning process to the modified pixel values to produce halftone pixel values having a reduced number of tone levels which are uniformly distributed with respect to the modified pixel values; and (c) transforming the halftone pixel values into output pixel values for permitting an output device to display the digital image so that visibility of halftone patterns is minimized.
Claim 2
Dependent Claim 32 words
The method as in claim 1, wherein the transformation of step (a) is implemented using a look-up table which stores the modified pixel value corresponding to each of the input pixel values.
Claim 3
Dependent Claim 17 words
The method as in claim 1, wherein the modified pixel values are linear with CIE L* values.
Claim 4
Dependent Claim 19 words
The method as in claim 1, wherein the multi-level halftoning process in step (b) is a multi-level dither process.
Claim 5
Dependent Claim 20 words
The method as in claim 1, wherein the multi-level halftoning process in step (b) is a multi-level error diffusion process.
Claim 6
Dependent Claim 32 words
The method as in claim 1, wherein the transformation of step (c) is implemented using a look-up table which stores the output pixel value corresponding to each of the halftone pixel values.
Claim 7
Dependent Claim 20 words
The method as in claim 1 further comprising the step of storing the halftone pixel values in a storage device.
Claim 8
Dependent Claim 26 words
The method as in claim 1, wherein steps (a), (b) and (c) are applied to each channel of a digital image having two or more channels.
Claim 9
Dependent Claim 24 words
The method as in claim 1, wherein the halftone pixel values are transmitted across a digital communication channel for displaying on a remote device.
Claim 10
Dependent Claim 13 words
The method as in claim 1, wherein the output device is a printer.

References Cited (Backward Citations)

No citation records indexed.

USPTO Annuity & Maintenance Windows

Maintenance schedule is calculated for granted US utility patents.

Assigned Categories & Tags

No categories assigned to this patent yet.

Assign Category Tag