Edge emphasizing circuit

• US 7,433,534 B2
• Filed: 05/23/2003
• Issued: 10/07/2008
• Est. Priority Date: 05/27/2002
• Status: Active Grant

• Current Assignee: Xacti Corporation (Office Support KK)
• Original Assignee: Sanyo Electric Company Limited (Panasonic Holdings Corporation)
• Inventors: Kawakubo, Takuji
• Primary Examiner(s): Allison; Andrae S.
• Application Number:
  US10/444,305
• Publication Number:
  US 20030219168A1
• Time in Patent Office: 1,964 Days
• Field of Search: 382/260, 382/266, 382162-167, 382199-200, 382/263, 345/611, 358/1.9, 348/252
• US Class Current: 382/266
• CPC Class Codes: G06T 2207/10024 Color image
• CPC Class Codes: G06T 2207/20032 Median filtering
• CPC Class Codes: G06T 2207/20192 Edge enhancement; Edge preservation
• CPC Class Codes: G06T 5/20 using local operators
• CPC Class Codes: G06T 5/75 Unsharp masking

Abstract

An edge emphasizing circuit includes a weighing addition circuit, and the weighing addition circuit performs on the basis of a weighing coefficient applied from a coefficient calculating circuit a weighing addition with respect to raw image data and data obtained by performing a filtering process on the raw image data by a median filter. Then, an aperture signal producing circuit produces an aperture signal on the basis of a result of the weighing addition. The aperture signal is in an adder superimposed on Y data output from a signal processing circuit, whereby an edge component of the Y data is emphasized.

Claims

1. An edge emphasizing circuit, comprising:

a filter which performs a filtering process on pixel data of a noted pixel forming raw image data representative of an object scene image so as to output processed pixel data;

a first creator which creates edge emphasizing data by subjecting to a weighted adding process the pixel data of the noted pixel forming the raw image data and the processed pixel data;

a second creator which creates luminance data based on the raw image data;

an adder which adds the edge emphasizing data created by said first creator to the luminance data created by said second creator;

a detector which detects a degree of an edge of a portion of the object scene image including the noted pixel out of the object scene image based on the pixel data of the noted pixel and pixel data of surround pixels which surround the noted pixel; and

a controller which controls said first creator based on a detection result of said detector such that a weighting amount added to the processed pixel data increases as the degree of the edge of the portion of the object scene image decreases.

2. An edge emphasizing circuit according to claim 1, wherein said filtering process is a median filtering process.

3. An edge emphasizing circuit according to claim 1, wherein the noted pixel is a pixel having color information of green.

4. An edge emphasizing circuit according to claim 2, wherein the noted pixel is a pixel having color information of green.

5. An edge emphasizing circuit according to claim 1, wherein any one of a plurality of colors is assigned to each pixel forming the raw image data, and a color assigned to each of the surround pixels is consistent with a color assigned to the noted pixel.