Image processing method and computer-readable recording medium containing image processing program

• US 7,460,700 B2
• Filed: 07/26/2004
• Issued: 12/02/2008
• Est. Priority Date: 07/24/2003
• Status: Expired due to Fees

• Current Assignee: J Morita Manufacturing Corporation (J. Morita Corporation), Matsumoto Dental University, Nihon University Educational Association
• Original Assignee: J Morita Manufacturing Corporation (J. Morita Corporation), Matsumoto Dental University, Nihon University Educational Association
• Inventors: Yamada, Ayuta, Tsunashima, Hitoshi, Arai, Yoshinori, Kanari, Hozumi
• Primary Examiner(s): Johns; Andrew W.
• Assistant Examiner(s): Bitar; Nancy
• Application Number:
  US10/565,895
• Publication Number:
  US 20070009144A1
• Time in Patent Office: 1,590 Days
• Field of Search: 382/131, 382/274, 382/154, 382/107, 382/128, 382/161, 348/169, 378/98.4
• US Class Current: 382/131
• CPC Class Codes: G06T 2200/04 involving 3D image data
• CPC Class Codes: G06T 2207/10081 Computed x-ray tomography [CT]
• CPC Class Codes: G06T 2207/20012 Locally adaptive
• CPC Class Codes: G06T 2207/30036 Dental; Teeth
• CPC Class Codes: G06T 5/20 using local operators
• CPC Class Codes: G06T 5/70 Denoising; Smoothing
• CPC Class Codes: G06T 5/94 based on local image properties, e.g. for local contrast enhancement
• CPC Class Codes: G06V 10/30 Noise filtering

Abstract

An image processing method which corrects a 3-dimensional CT data value obtained from a 3-dimensional object is provided. The image processing method comprises: a threshold setting step of setting a threshold value used for generating a correction value from the 3-dimensional CT data value obtained from the 3-dimensional object; an average calculating step of calculating an average value of a 3-dimensional CT data block comprising a 3-dimensional CT data element of a correction target and a plurality of 3-dimensional CT data elements in a neighborhood of the 3-dimensional CT data element of the correction target; and a correction step of correcting the 3-dimensional CT data value by using the threshold value set in the threshold setting step and the average value obtained in the average calculating step.

Claims

1. An image processing method which processes 3-dimensional CT data obtained from a 3-dimensional object, comprising:

an integrated value calculating step of calculating an integrated value of a predetermined number of 3-dimensional CT data elements which are consecutive with a currently observed 3-dimensional CT data element being set as a starting point, for each of a plurality of directions with the currently observed 3-dimensional CT data element being set as a starting point;

a sum calculating step of calculating both a sum of a predetermined number of upper-rank integrated values among respective integrated values calculated for the plurality of directions in the integrated value calculating step and a sum of a predetermined number of lower-rank integrated values among the respective integrated values calculated for the plurality of directions in the integrated value calculating step;

a correction step of correcting a currently observed 3-dimensional CT data element based on the sum of the predetermined number of upper-rank integrated values and the sum of the predetermined number of lower-rank integrated values; and

a judgment step of comparing the corrected 3-dimensional CT data element obtained in the correction step with a predetermined threshold value, and determining the currently observed 3-dimensional CT data element as being data of a processing target when the corrected 3-dimensional CT data element is larger than the threshold value.

2. A computer-readable recording medium in which an image processing program embodied therein for causing a computer to execute the image processing method according to claim 1 is recorded.