Geometric Correction, Scene Registration, and Object Extraction for Digital Camera Image Analysis

• Main Authors: Wan-Hsing Hsu, 徐萬星
• Other Authors: Wen-Hsiang Tsai
• Format: Others
• Language: en_US
• Published: 1999
• Online Access: http://ndltd.ncl.edu.tw/handle/52305096587862526151

碩士 === 國立交通大學 === 資訊科學系 === 87 === When a scene is taken from a digital camera, it may not be entirely included in the taken single image. Also, if the scene is forced to be included in the image by adjusting the focal length, the resolution of the scene in the image will be decreased. This gives us the motivation of studying the use of multiple images to construct a scene. A new approach for this purpose is proposed. The images used for scene construction are taken from different camera views such that the scene is entirely covered by these images. Before the construction process, geometric correction is conducted on these images first to eliminate geometric distortion in these images, which is caused by imprecise camera lens geometry. Then, an iterative generalized Hough transform is proposed to obtain corresponding matching points within these images. The matching points are then used to stitch these images for scene construction. To avoid serious color differences in these images caused by image taking at different times with different brightness, a color correction technique is also proposed, by which the constructed scene can be modified to look smoother. Additionally, a semi-automatic object extraction method is proposed. A close contour of an object is drawn manually by the use of the computer mouse. Then, by using the Sobel operator to track the boundary points of the object, the object shape boundary is extracted within the close contour. The method is applicable even when the background of the object is complicated. Good experimental results are also shown to prove the feasibility of the proposed approaches.