An Automated Segmentation Approach for DNA Microarray Image

• Main Authors: Cheng-Wei Huang, 黃正瑋
• Other Authors: Yuan-Kai Wang
• Format: Others
• Language: zh-TW
• Published: 2004
• Online Access: http://ndltd.ncl.edu.tw/handle/21170624148730371692

碩士 === 輔仁大學 === 電子工程學系 === 92 === DNA microarray is a new tool used to examine expression levels for thousands of genes simultaneously. However, large amounts of bioinformation will be produced in DNA microarray experiments. It’s extremely urgent to develop automatic and precise tools for the analysis of DNA microarray. Image analysis is the first important step for the automatic processing of microarray experiments. In this paper, a novel approach for accurate spot finding in DNA microarray images using active contour model is proposed. In our approach, a microarray image is first transformed into a gray-level one. Wavelet-based profile analysis is then performed for building orthogonal grid system of the image. Each spot is enclosed within a grid after the wavelet-based profile analysis. The boundary of the grid is specified as initial contour of the spot. By shrinking the initial contour through energy conservation, more precise contour of the spot will be located. The approach is tested on microarray images obtained from Stanford Microarray Database. Comprehensive experiments show highly encouraging results. Major contributions of the proposed approach include the followings: (1) We solve the problem of image rotation without manual adjustment. (2) The detection is robust with irregular spot gaps. (3) Our approach is not affected by variations of color and size of spots. (4) Our approach performs well on different number of input channels. Besides, the proposed approach can not only handle multiple spots in microarray images, but also find more precise contours of spots.