Dot center tracking in optical storage systems using ink dots

• US 6,459,495 B1
• Filed: 07/10/1998
• Issued: 10/01/2002
• Est. Priority Date: 07/15/1997
• Status: Expired due to Term

• Current Assignee: Google LLC (Alphabet Inc.)
• Original Assignee: Silverbrook Research Pty Limited
• Inventors: Silverbrook, Kia
• Primary Examiner(s): Grant, II, Jerome
• Application Number:
  US09/112,785
• Time in Patent Office: 1,544 Days
• Field of Search: 358/520, 358/1.09
• US Class Current: 358/520
• CPC Class Codes: B41J 2/14 Structure thereof only for on-demand ink jet heads
• CPC Class Codes: B41J 2/16 Production of nozzles
• CPC Class Codes: B41J 2/1628 dry etching
• CPC Class Codes: B41J 2/1629 wet etching
• CPC Class Codes: B41J 2/1631 photolithography
• CPC Class Codes: B41J 2/1632 machining
• CPC Class Codes: B41J 2/1642 thin film formation by CVD [chemical vapor deposition]
• CPC Class Codes: B41J 2/1645 thin film formation by spincoating
• CPC Class Codes: B41J 2/1646 thin film formation by sputtering
• CPC Class Codes: B41J 2/16585 for paper-width or non-reciprocating print heads
• CPC Class Codes: B41J 2/17596 Ink pumps, ink valves
• CPC Class Codes: B41J 2002/041 Electromagnetic transducer
• CPC Class Codes: B41J 3/36 for portability , i.e. hand-held printers or laptop printers B41J3/4075 takes precedence
• CPC Class Codes: B82Y 30/00 Nanotechnology for materials or surface science, e.g. nanocomposites
• CPC Class Codes: G06F 21/79 in semiconductor storage media, e.g. directly-addressable memories
• CPC Class Codes: G06F 21/86 Secure or tamper-resistant housings
• CPC Class Codes: G06F 2221/2129 Authenticate client device independently of the user
• CPC Class Codes: G06K 1/121 by printing code marks applying code marks to labels B65C9/46; marking or coding completed packages B65B61/26
• CPC Class Codes: G06K 19/06037 multi-dimensional coding
• CPC Class Codes: G06K 7/14 using light without selection of wavelength, e.g. sensing reflected white light G06K7/10831 - G06K7/1097 take precedence
• CPC Class Codes: G06K 7/1417 : 2D bar codes
• CPC Class Codes: G11C 11/56 : using storage elements with more than two stable states represented by steps, e.g. of voltage, current, phase, frequency
• CPC Class Codes: H04N 1/00127 : Connection or combination of a still picture apparatus with another apparatus, e.g. for storage, processing or transmission of still picture signals or of information associated with a still picture
• CPC Class Codes: H04N 1/00326 : with a data reading, recognizing or recording apparatus, e.g. with a bar-code apparatus arrangements for the associated working of recording or reproducing apparatus with related apparatus G11B31/00
• CPC Class Codes: H04N 1/0044 : for image preview or review, e.g. to help the user position a sheet
• CPC Class Codes: H04N 1/00965 : using a plug-in memory module, e.g. memory card, memory stick
• CPC Class Codes: H04N 1/2112 : using still video cameras
• CPC Class Codes: H04N 1/2154 : the still video camera incorporating a hardcopy reproducing device, e.g. a printer
• CPC Class Codes: H04N 1/32101 : Display, printing, storage or transmission of additional information, e.g. ID code, date and time or title
• CPC Class Codes: H04N 1/32144 : embedded in the image data, i.e. enclosed or integrated in the image, e.g. watermark, super-imposed logo or stamp
• CPC Class Codes: H04N 2101/00 : Still video cameras
• CPC Class Codes: H04N 2201/0008 : Connection or combination of a still picture apparatus with another apparatus
• CPC Class Codes: H04N 2201/3222 : of processing required or performed, e.g. forwarding, urgent or confidential handling
• CPC Class Codes: H04N 2201/3269 : of machine readable codes or marks, e.g. bar codes or glyphs
• CPC Class Codes: H04N 2201/3276 : of a customised additional information profile, e.g. a profile specific to a user ID
• CPC Class Codes: H04N 2201/328 : Processing of the additional information
• CPC Class Codes: H04N 23/00 : Cameras or camera modules comprising electronic image sensors; Control thereof
• CPC Class Codes: H04N 5/2628 : Alteration of picture size, shape, position or orientation, e.g. zooming, rotation, rolling, perspective, translation

Abstract

A method of converting a scanned image comprising scanned pixels to a corresponding bitmap image, said method comprising the steps of, for each bit in the bitmap image;

a. determining an expected location in said scanned image of a current bit from the location of surrounding bits in said scanned image;

b. determining a likely value of said bit from the values at the locations of expected corresponding pixels in said scanned image;

c. determining a centroid measures of the center of the center of the expected intensity at the said expected location;

d. determining similar centroid measures for adjacent pixels surrounding said current bit in said scanned image and;

e. where said centroid measure is improved relative to said expected location, adjusting said expected location to be an adjacent pixel having an improved centroid measure.

Claims

1. A method of converting a scanned image comprising scanned pixels to a corresponding bitmap image, said method comprising the steps of, for each bit in the bitmap image;

a. determining an expected location in said scanned image of a current bit from the location of surrounding bits in said scanned image;

b. determining a likely value of said bit from the values at a locations of expected corresponding pixels in said scanned image;

c. determining a centroid measurement of the centre of an expected intensity at the said expected location;

d. determining similar centroid measurement for adjacent pixels surrounding said current bit in said scanned image and;

e. where said centroid measurement of the centre of expected intensity is improved relative to said expected location, adjusting said expected location to be an adjacent pixel having an improved centroid measurement.