Browse Prior Art Database

Color Information Embedding into Bi-Level Image Data

IP.com Disclosure Number: IPCOM000118866D
Original Publication Date: 1997-Aug-01
Included in the Prior Art Database: 2005-Apr-01
Document File: 4 page(s) / 72K

Publishing Venue

IBM

Related People

Inoue, O: AUTHOR [+2]

Abstract

Disclosed is a method to encode a Color Image Data into a color-information-embedded Bi-level Image in a way that the resulted image itself is the bi-level version of the original one and the original color image can be retrieved by decoding the embedded color information. Thus, the Bi-level Image obtained by this method from a color image can be displayed or printed as a color image by decoding the embedded color information or can be displayed or printed as a normal bi-level image leaving intact. The typical size of the encoded bi-level image is 4-by-4 black/white dots per each color pixel.

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Color Information Embedding into Bi-Level Image Data

      Disclosed is a method to encode a Color Image Data into a
color-information-embedded Bi-level Image in a way that the resulted
image itself is the bi-level version of the original one and the
original color image can be retrieved by decoding the embedded color
information.  Thus, the Bi-level Image obtained by this method from a
color image can be displayed or printed as a color image by decoding
the embedded color information or can be displayed or printed as a
normal bi-level image leaving intact.  The typical size of the
encoded bi-level image is 4-by-4 black/white dots per each color
pixel.

      The Figures show an example encoding scheme that encodes a 256
(8-bit) color pixel into 16 black/white dots (4-by-4 dot matrix)
keeping the luminance at each pixel of the original color image as
much as possible, which can help human recognition of the encoded
image as the  monochrome version of the original color one.  In this
example, the 256  colors are the combination of 7 levels of RED
gradation, 8 levels of GREEN and 4 levels of BLUE (so, actually 224
colors - though the difference is not significant), and 6 dots are
allocated to RED, 7 dots  to GREEN and 3 dots to BLUE out of the
encoded 16 dots, as Fig. 1 shows.  The allocation to each color
reflects human eye sight sensitivity  to colors.  Fig. 2 shows how
the gradation of seven levels (0 to 6) of  RED will be encoded into
the pattern of the...