Image processing method and image processing apparatus

• US 7,492,947 B2
• Filed: 10/08/2003
• Issued: 02/17/2009
• Est. Priority Date: 04/19/2001
• Status: Expired due to Term

• Current Assignee: Toshiba Medical Systems Corporation (Canon Inc.)
• Original Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Inventors: Nanbu, Kyojiro
• Primary Examiner(s): Le; Brian Q
• Application Number:
  US10/680,256
• Publication Number:
  US 20040066978A1
• Time in Patent Office: 1,959 Days
• Field of Search: 382/209, 382217-222, 382236-238, 382/266
• US Class Current: 382/209
• CPC Class Codes: G06T 2207/10072 Tomographic images
• CPC Class Codes: G06T 2207/20192 Edge enhancement; Edge preservation
• CPC Class Codes: G06T 2207/30004 Biomedical image processing
• CPC Class Codes: G06T 5/20 using local operators
• CPC Class Codes: G06T 5/50 using two or more images, e.g. averaging or subtraction
• CPC Class Codes: G06T 5/70 Denoising; Smoothing

Abstract

This invention consists in an image processing method in which the similarity between a first pixel and a second pixel constituting an image is numerically given by statistical testing, and the values of the first and second pixels are averaged when the similarity numerically given is high, whereas the first and second pixel values are not averaged when the determined similarity is low, whereby an image with noises suppressed is obtained without spoiling a spatial resolution as well as a temporal resolution.

Claims

1. An image processing apparatus comprising:

decision means for deciding a similarity between a first pixel and a second pixel of an image based on a plurality of images obtained by photographing an identical subject at different times; and

average means for subjecting the first pixel and the second pixel to weighted averaging on a basis of a decided result by the decision means,

wherein the average means includes determination means for determining a weighting factor on a basis of the decided result, and multiplication means for multiplying values of the first pixel and the second pixel by the weighting factor,

the average means multiplies the second pixel value by a large weighting factor by the multiplication means when the similarity between the first pixel and the second pixel is high, and multiplies the second pixel value by a small weighting factor when the similarity is low, and

the average means subjects the weighted first pixel value and second pixel value to the weighted averaging.

2. An image processing apparatus comprising:

numerical means for numerically giving a similarity between a first pixel and a second pixel which constitute an image, by statistical testing; and

average means for averaging values of the first pixel and the second pixel when the numerical similarity is high in the numerical means, and for not averaging the first pixel value and the second pixel value when the determined similarity is low.

3. An image processing apparatus comprising:

a numerical unit configured to numerically give a similarity between a first pixel and a second pixel which constitute an image, by statistical testing; and

an average unit configured to average values of the first pixel and the second pixel when the numerical similarity is high in the numerical unit, and to not average the first pixel value and the second pixel value when the determined similarity is low.