• International Journal of Control, Automation, and Systems
• /
• 제1권3호
• /
• pp.332-338
• /
• 2003

Content-based image retrieval is the research of images from database, that are visually similar to given image examples. Gabor functions and Gabor filters are regarded as excellent methods for feature extraction and texture segmentation. However, they have a disadvantage not to perform well in case of a rotated image because of its direction-oriented filter. This paper proposes a method of extracting local texture features from blocks with central interest points detected in an image and a rotation invariant Gabor wavelet filter. We also propose a method of comparing pattern histograms of features classified by VQ (Vector Quantization) among images.

• 대한전자공학회:학술대회논문집
• /
• 대한전자공학회 2000년도 제13회 신호처리 합동 학술대회 논문집
• /
• pp.901-904
• /
• 2000

A direct authentication from gray-scale image, instead of the conventional multi-step preprocessing, is proposed using Gabor filter-based features from the gray-scale fingerprint around core point. The core point is located as a reference point for the translation invariant matching. And its principal symmetry axis is detected for the rotation invariant matching from its neighboring region centered at the core point. And then fingerprint is divided into non-overlapping blocks with respect to the core point and features are directly extracted form the blocked gray level fingerprint using Gabor filter. The proposed fingerprint authentication is based on the Euclidean distance between the corresponding Gabor features of the input and the template fingerprints. Experiments are conducted on 300${\times}$300 fingerprints obtained from a CMOS sensor with 500 dpi resolution, and the proposed method could lower the False Reject Rate(FRR) to 18.2% under False Acceptance Rate(FAR) of 0%.

• 대한전자공학회:학술대회논문집
• /
• 대한전자공학회 2000년도 ITC-CSCC -1
• /
• pp.446-449
• /
• 2000

A direct RTI(Rotation and translation invariant) fingerprint identification is proposed using the GCMs(generalized complex moments) and Gabor filter-based features from the grey level fingerprint around core point. The core point is located as reference point for the translation invariant matching. And its symmetry axis is detected for the rotation invariant matching from its neighboring region centered at the core point. And then, fingerprint is divided into non-overlapping blocks with respect to the core point and, in contrast to minutiae-based method using various processing steps, features are directly extracted from the blocked grey level fingerprint using Gabor filter, which provides information contained in a particular orientation in the image. The Proposed fingerprint identification is based on the Euclidean distance of the corresponding Gabor features between the input and the template fingerprint. Experiments are conducted on 300 ${\times}$ 300 fingerprints obtained from the CMOS sensor with 500 dpi resolution, and the proposed method could obtain 97% identification rate.

• 대한전기학회논문지:시스템및제어부문D
• /
• 제51권7호
• /
• pp.323-326
• /
• 2002

As multimedia database and digital image libraries are enlarged, CBIR(Content Based Image Retrieval) has been getting importance for the efficient search. Generally, CBIR uses primitive features such as color, shape, texture and so on. Among various methods of CBIR, Gabor wavelet has good image retrieval performance with texture features but it has a disadvantage which does not perform well for a rotated image because of its direction oriented filter. In this paper, we propose a new method to solve this problem by modifying Gabor filter for all directions. And then we will compare the searching performance of the proposed method with those of conventional image retrieval methods through experiments with trademarks.

• Journal of Information Processing Systems
• /
• 제9권1호
• /
• pp.103-116
• /
• 2013

Prostate cancer is one of the most frequent cancers in men and is a major cause of mortality in the most of countries. In many diagnostic and treatment procedures for prostate disease accurate detection of prostate boundaries in transrectal ultrasound(TRUS) images is required. This is a challenging and difficult task due to weak prostate boundaries, speckle noise and the short range of gray levels. In this paper a method for automatic prostate segmentation in TRUS images using Gabor feature extraction and snake-like contour is presented. This method involves preprocessing, extracting Gabor feature, training, and prostate segmentation. The speckle reduction for preprocessing step has been achieved by using stick filter and top-hat transform has been implemented for smoothing the contour. A Gabor filter bank for extraction of rotation-invariant texture features has been implemented. A support vector machine(SVM) for training step has been used to get each feature of prostate and nonprostate. Finally, the boundary of prostate is extracted by the snake-like contour algorithm. A number of experiments are conducted to validate this method and results showed that this new algorithm extracted the prostate boundary with less than 10.2% of the accuracy which is relative to boundary provided manually by experts.

• 한국정보처리학회:학술대회논문집
• /
• 한국정보처리학회 2014년도 추계학술발표대회
• /
• pp.520-522
• /
• 2014

Due to the availability of easy-to-use and powerful image editing tools, the authentication of digital images cannot be taken for granted and it gives rise to non-intrusive forgery detection problem because all imaging devices do not embed watermark. Forgery detection plays an important role in this case. In this paper, an effective framework for passive-blind method for copy-move image forgery detection is proposed, based on Gabor filter which is robust to illumination, rotation invariant, robust to scale. For the detection, the suspicious image is selected and Gabor wavelet is applied from whole scale space and whole direction space. We will extract the mean and the standard deviation as the texture features and feature vectors. Finally, a distance is calculated between two textures feature vectors to determine the forgery, and the decision will be made based on that result.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2001년도 하계학술대회 논문집 D
• /
• pp.2637-2639
• /
• 2001

디지털 기술의 발전과 더불어 방대한 양의 영상데이터가 발생되어 데이터베이스화되고 있으며, 이러한 데이터베이스 상에서의 효율적인 데이터 검색은 중요한 문제가 되었다. 현재 영상의 색상, 형태 및 질감 특성 등을 사용하는 다양한 영상 검색 기법들이 제안되고 있으며 본 연구에서는 영상의 특징 정보로서 질감 특성인 Gabor 웨이블릿 특징을 이용한 검색 기술을 제안하고자 한다. 기존의 Gabor 웨이블릿 특징을 이용한 방법은 영상의 회전에 대해 동작하지 못하는 단점을 가지고 있으며 본 연구에서는 웨이블릿 필터를 수정함으로써 이러한 문제를 해결하고자 한다. 트레이드마크 영상 데이터베이스 상에서 회전 문제 등을 포함한 다양한 검색 실험을 수행함으로써 기존의 검색 방법들과 제안한 방법을 비교 평가하고자 한다.

• 디지털콘텐츠학회 논문지
• /
• 제15권6호
• /
• pp.675-682
• /
• 2014

전립선은 남자에게만 있는 장기이다. 전립선의 질병을 진단하기 위하여 일반적으로 TRUS 영상이 사용되는데, 희미한 전립선 경계나 잡음, 좁은 그레이 레벨 분포 때문에, 전립선의 경계를 검출하는 것은 상당히 어려운 작업 중의 하나이다. 본 논문에서는 SVM을 사용하여 TRUS 영상에서 자동적으로 전립선 분할을 하는 방법을 제안한다. 이 방법은 전처리, 가버 특징 추출, 훈련, 전립선 분할 과정으로 진행된다. 전처리 과정에서 잡음 제거는 스틱 필터와 top-hat 변환이 적용된다. 회전 불변 텍스처 추출을 위하여 가버 필터 뱅크가 사용된다. 훈련과정에서 SVM은 전립선과 비전립선의 각 특징을 얻기 위해 사용되며, 마지막으로 전립선 경계가 추출된다. 여러 실험 결과로 제안 방법은 충분히 유효하고, 의사의 수동 추출 방법과 비교했을 때 10%미만의 경계 차이를 보였다.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2002년도 하계학술대회 논문집 D
• /
• pp.2595-2597
• /
• 2002

오늘날 많은 디지털 저장 매체의 발달로 방대한 양의 영상 데이터가 데이터베이스화 되고 있으며 이러한 데이터베이스에서 필요한 영상 데이터론 효율적으로 검색하는 방범이 중요한 문제로 대두되고 있다. 현재 영상의 색상, 형태 및 질감 특성을 사용하여 다양한 영상 검색 방법이 제안되고 있으며 본 연구에선 이중 질감을 특징으로 하는 Gator 특징 벡터를 사용하고자 한다. 즉, 영상의 인터레스트 포인트를 찾아내어 그 점에서 Gabor 웨이블릿을 이용하여 특징 벡터를 추출하고 VQ를 기반으로 한 히스토그램 인터섹션 방법을 이용하여 영상 검색을 한다. 기존의 Gator 웨이블릿 방법은 영상의 회전에 대해 잘 동작하지 못하는 단점을 가지고 있으며 이는 회전 영상에 대한 검색율 저하에 크게 작용한다. 이 문제를 해결하고자 본 논문에선 회전 불변 Gabor 필터를 이용한 영상 검색 방법을 제안하고자 한다.