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US6563513B1 Expired / Lapsed US ⏱️ 0.0 years remaining

Image processing method and apparatus for generating low resolution, low bit depth images

Assignee: Eastman Kodak Co
•
Filing: 2000-05-11
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Granted: 2003-05-13
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Expires: 2020-05-11
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Abstract

Abstract A digital image processing method for generating a low resolution, low bit depth digital image from a higher resolution, higher bit depth input color digital image, includes the steps of: generating a gray scale image from the input color digital image; generating a valley image; filtering the valley image with a rank order filter to produce a filtered valley image; thresholding the filtered valley image to generate a binary valley image; generating a shadow image and a highlight image from the gray scale image; combining the shadow image, the highlight image, and the binary valley image to produce a combined binary image; and sub-sampling the combined binary image to a desired low resolution.

Inventors

  • 👤 Qing Yu
  • 👤 Jiebo Luo
  • 👤 Richard A. Simon

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-09 14:10
CPC Classifications
G; G06; G06T; G06T3/00; G06T3/40; G06T3/403

Claims Analysis

Total Claims: 13
Claim 1
Independent Claim 125 words
A digital image processing method for generating a low resolution, low bit depth digital image from a higher resolution, higher bit depth input color digital image, comprising the steps of: a) generating a gray scale image from the input color digital image; b) generating a valley image; c) filtering the valley image with a rank order filter to produce a filtered valley image; d) thresholding the filtered valley image to generate a binary valley image; e) generating a shadow image and a highlight image from the gray scale image; f) combining the shadow image, the highlight image, and the binary valley image to produce a combined binary image; and g) sub-sampling the combined binary image to generate an output binary image with desired low resolution.
Claim 2
Dependent Claim 125 words
A digital image processing method for generating a low resolution, low bit depth digital image from a higher resolution, higher bit depth input color digital image, comprising the steps of: a) generating a gray scale image from the input color digital image; b) generating a valley image; c) filtering the valley image with a rank order filter to produce a filtered valley image; d) thresholding the filtered valley image to generate a binary valley image; e) generating a shadow image and a highlight image from the gray scale image; f) combining the shadow image, the highlight image, and the binary valley image to produce a combined binary image; and g) sub-sampling the combined binary image to generate an output binary image with desired low resolution.
Claim 3
Dependent Claim 33 words
The method claimed in claim 1 , wherein the input digital image is larger than a predetermined size, further comprising the step of first sub-sampling the input digital image to the predetermined size.
Claim 4
Dependent Claim 14 words
The method claimed in claim 2 , wherein the predetermined size is 480×320 pixels.
Claim 5
Dependent Claim 40 words
The method claimed in claim 1 , wherein the valley image is generated by: a) blurring the gray scale image to generate a blurred gray scale image; and b) subtracting the blurred gray scale image from the gray scale image.
Claim 6
Dependent Claim 88 words
The method claimed in claim 1 , wherein the shadow image and the highlight image are generated by the steps of: a) generating a histogram of the gray scale image; b) smoothing the histogram; c) locating a first minimum in the histogram from either end of the histogram; and d) designating all pixels with values below the first minimum as the shadow image and setting these pixels to zero, and designating all the pixels above the second minimum as the highlight image and setting these values to one.
Claim 7
Dependent Claim 81 words
The method claimed in claim 1 , wherein the combining step includes the steps of: a) if a pixel value in the shadow image is a zero, setting the corresponding pixel value in the combined image to zero; b) if a pixel value in the highlight image is a one, setting the corresponding pixel value in the combined image to one; and c) otherwise, setting the corresponding pixel value in the combined image to the value of the binary valley image.
Claim 8
Dependent Claim 20 words
A computer storage medium having instructions stored thereon for causing a computer to perform the method of claim 1 .
Claim 9
Dependent Claim 47 words
The computer storage medium claimed in claim 7 , wherein the input digital image in the method of claim 1 is larger than a predetermined size, and the method of claim 1 further comprising the step of first sub-sampling the input digital image to the predetermined size.
Claim 10
Dependent Claim 16 words
The computer storage medium claimed in claim 8 , wherein the predetermined size is 480×320 pixels.
Claim 11
Dependent Claim 48 words
The computer storage medium claimed in claim 7 , wherein the valley image in the method of claim 1 is generated by: a) blurring the gray scale image to generate a blurred gray scale image; and b) subtracting the blurred gray scale image from the gray scale image.
Claim 12
Dependent Claim 96 words
The computer storage medium claimed in claim 7 , wherein the shadow image and the highlight image in the method of claim 1 are generated by the steps of: a) generating a histogram of the gray scale image; b) smoothing the histogram; c) locating a first minimum in the histogram from either end of the histogram; and d) designating all pixels with values below the first minimum as the shadow image and setting these pixels to zero, and designating all the pixels above the second minimum as the highlight image and setting these values to one.
Claim 13
Dependent Claim 89 words
The computer storage medium claimed in claim 7 , wherein the combining step in the method of claim 1 includes the steps of: a) if a pixel value in the shadow image is a zero, setting the corresponding pixel value in the combined image to zero; b) if a pixel value in the highlight image is a one, setting the corresponding pixel value in the combined image to one; and c) otherwise, setting the corresponding pixel value in the combined image to the value of the binary valley image.

References Cited (Backward Citations)

US5978035A Cited
US5825936A Cited
US20020057850A1 Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 2006-05-12 2006-11-11 2007-05-13 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 2010-05-12 2010-11-11 2011-05-13 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2014-05-12 2014-11-11 2015-05-13 $7700.00 Window Closed / Lapsed

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