Contrast Enhancement for X-ray Images Based on Combined Enhancement of Scaling and Wavelet Coefficients.
- Author:
Chun Joo PARK
1
;
Do Il KIM
;
Do Yoon JANG
;
Han Been YOON
;
Bo Young CHOE
;
Ho Kyung KIM
;
Hyoung Koo LEE
Author Information
1. Department of Biomedical Engineering, College of Medicine, The Catholic University of Korea, Seoul, Korea. hklee@catholic.ac.kr
- Publication Type:Original Article
- Keywords:
X-ray image enhancement;
Wavelet transform;
Contrast enhancement
- MeSH:
Colon, Sigmoid;
Mammography;
Noise;
Wavelet Analysis
- From:Korean Journal of Medical Physics
2008;19(3):150-156
- CountryRepublic of Korea
- Language:English
-
Abstract:
An applied technique of contrast enhancement for X-ray image is proposed which is based on combined enhancement of scaling and wavelet coefficients in discrete wavelet transform space. Conventional contrast enhancement methods such as contrast limited adaptive histogram equalization (CLAHE), multi-scale image contrast amplification (MUSICA) and gamma correction were applied on scaling coefficients to enhance the contrast of an original. In order to enhance the detail as well as reduce the blurring caused by up scaling of contrast modified scale coefficients from lower resolution, the sigmoid manipulation function was used to manipulate wavelet coefficients. The contrast detail mammography (CDMAM) phantom was imaged and processed to measure the image line profile of results and contrast to noise ratio (CNR) comparatively. The proposed technique produced better results than direct application of various contrast enhancement methods on image itself. The proposed method can enhance contrast, and also suppress the amplification of noise components in a single process. It could be useful for various applications in medical, industrial and graphical images where contrast and detail are of importance.
