Method of decoding data encoded in a monochrome medium

• US 7,177,476 B2
• Filed: 02/28/2002
• Issued: 02/13/2007
• Est. Priority Date: 02/28/2002
• Status: Expired due to Fees

• Current Assignee: Eastman Kodak Company
• Original Assignee: Eastman Kodak Company
• Inventors: Wong, Victor C., Jones, Robert S., Williams, Donald R., Weil, Richard, Abhyankar, Vishwas G., Breslawski, Robert, Bayley, Robert B., Narayan, Badhri, Reisch, Robert V., Duncan, Robert G.
• Primary Examiner(s): Do; Anh Hong
• Application Number:
  US10/086,142
• Publication Number:
  US 20030161016A1
• Time in Patent Office: 1,811 Days
• Field of Search: 382/232, 382/233, 382/237, 382/162, 382/166, 382/239, 348/448, 348/701, 356/405, 358/515, 358/527, 358/520, 358/3.14, 358/3.2, 358/1.9, 358/539, 358/426.02, 386/33, 345/60.5, 345/440, 345/591
• US Class Current: 382/237
• CPC Class Codes: H04N 1/40012 Conversion of colour to monochrome
• CPC Class Codes: H04N 1/41 Bandwidth or redundancy reduction by scanning H04N1/17 ; methods or arrangements for coding, decoding, compressing or decompressing digital video signals H04N19/00
• CPC Class Codes: H04N 1/64 Systems for the transmission or the storage of the colour picture signal; Details therefor, e.g. coding or decoding means therefor H04N19/00 takes precedence

Abstract

A method for decoding data that has been encoded in a monochrome medium utilizing the capability of the medium for grayscale resolution. A document is processed to provide an image in electronic format, in which each pixel has an assigned data value with a given bit depth. A mapping operation is performed for generating a monochrome data word (120), preferably having a reduced bit depth. The monochrome data word (120) can be used to encode multiple data fields (114, 116, 118). A printer (92) then produces a preserved document record (90) in which the appropriate monochrome data word (120) determines the grayscale value for each pixel. To decode the stored data, a scanner (86) is employed to obtain the grayscale value from the preserved document record (90). For each pixel, the grayscale value is then decomposed into multiple data fields (114, 116, 118), which can then be decoded to provide the information that was originally encoded.

Claims

1. A method of preserving data about a document that has been received in electronic form, the method comprising:

(a) encoding data about the document in a monochrome medium by;

(a1) converting the document to a rasterized image in which each pixel is assigned a raster value;

(a2) for each pixel;

(a2a) assigning a data word having a first bit depth, said data word comprising a first data field and a second data field;

(a2b) encoding a first component of said raster value into said first data field;

(a2c) encoding a second data value into said second data field;

(a2d) generating a grayscale data value comprising said first data field and said second data field; and

,

(a2e) forming, onto the monochrome medium, a grayscale pixel conditioned by said grayscale data value;

(b) responding to a request for said first component of said raster value for each said grayscale pixel, by;

(b1) scanning said grayscale pixel to obtain a monochrome density value having a second bit depth;

(b2) decomposing said monochrome density value to obtain said first data field; and

(b3) decoding said first data field to obtain said first component of said raster value.

2. The method of claim 1 wherein said first bit depth is larger than said second bit depth.

3. A method of preserving data about a document that has been received in electronic form, the method comprising:

(a) encoding data about the document in a monochrome medium by;

(a1) converting the document to a rasterized image in which each pixel is assigned a raster value;

(a2) for each pixel;

(a2a) assigning a data word having a first bit depth, said data word comprising a first data field and a second data field;

(a2b) encoding a first component of said raster value into said first data field;

(a2c) encoding a second data value into said second data field;

(a2d) generating a grayscale data value comprising said first data field and said second data field; and

,

(a2e) forming, onto the monochrome medium, a grayscale pixel conditioned by said grayscale data value;

(b) responding to a request for said second data value for each said grayscale pixel, by;

(b1) scanning said grayscale pixel to obtain a monochrome density value having a second bit depth;

(b2) decomposing said monochrome density value to obtain said second data field;

(b3) decoding said second data field to obtain said second data value.

4. The method of claim 3 wherein said first bit depth is larger than said second bit depth.