【作者】 秦岭；

【导师】 罗三定；

【作者基本信息】 中南大学 ， 控制科学与工程， 2010， 硕士

【摘要】 医学图像处理是计算机视觉领域的一个重要分支,是数字图像技术在生物医学工程中的应用。对医学图像进行特征提取,可以有效地指导临床诊断,同时也为人体信息数字化的科学研究打下基础。不同的医学股骨透视图像特点不同,故采用不同的方法提取其特征。针对X光图像不够清晰、不易对股骨进行直接分割的特点,采用数据拟合的方法,结合股骨特征模型直接从图像数据中拟合出股骨的特征参数。针对图像比较清晰的序列CT图像,采用先对二维股骨图像进行轮廓分割,再对多层轮廓结果进行特征提取的方法。在提取股骨单帧轮廓时,提出自适应辐射线法分割类圆形股骨轮廓。根据图像拍摄初试条件确定骨骼大致位置,利用少量辐射线对类圆形股骨进行精确定位并计算得到类圆形的均半径,使用数量适当的辐射线扫描确定股骨边缘点,再结合边缘点可信度及圆滑指数对边缘点进行修正。最终实现了对类圆形股骨轮廓的准确提取。在提取股骨序列轮廓时提出关联帧间跟踪法,结合相邻帧的股骨轮廓确定当前帧股骨轮廓。根据相邻帧的股骨轮廓边界矩形,确定当前帧轮廓包围矩形；依据相邻帧股骨轮廓将当前帧包围矩形内图像转化为边缘极展开图像；结合边缘点的可信度以及圆滑指数等对边缘点进行修正确定股骨轮廓；对双向股骨轮廓信息进行融合,确定最终股骨轮廓,并据此轮廓线实现骨骼的三维重建,获得完整的三维骨骼信息。最后,对所做的研究工作进行了总结,提出了需要开展的后续工作的思路,对进一步的研究具有一定的指导意义。更多还原

【Abstract】 As one research branch in the field of computer vision, processing medical image is an important application of computer graphics and digital image processing in the biomedical engineering. Feature extraction, the foundation of digital research, can be used to guide Clinical Diagnosis effectively.Medical perspective images having different features result in different methods used to extract the skeletal contour for femurs. Data fitting, combining with feature models of femur, is applied to acquire the feature parameters of cloudy X-Ray images. While, for distinct CT sequence images, extracting skeletal contour for femurs in 2-D images, followed by feature extraction of multilayer contour is a better choice.The method of radiating lines with self-adapting is used to acquire the contour of femur similar to a circle object when extracting contour of femur in a single image. Firstly, according to initial conditions can be used to fix the position of a femur approximately. Furthermore a few radiating lines go a step further to get more accurate the position of the femur and gain the radius of the contour liking a circle. Finally, reasonable quantity of radiating lines scanning is used to confirm the edge points of the femur and the results will be revised on the basis of the reliability of edge points and smoothing index. Therefore, the contour of a femur liking a circle can be obtained.The current contour of a femur can be gained by tracking a sequence of frames and the contour of a femur in consecutive frames in the process of extracting contours in sequence images. Rectangular region of a femur in current frame can be confirmed by the rectangular regions of a femur in consecutive frames, and then the edges of the image based on its polar coordinates will be acquired. These edge points extracted will be revised in further according to the reliability and smoothing index. After mixing the contours of bidirectional femur together, the ultimate contour of a femur will be gained and these results will be used to realize the 3-D reconstruction of a femur and conclude the whole 3-D femur information. Finally, on the basis of the summarized work, the essay has put forward some useful suggestions in the later study work, which is in great favor of guiding the further study work.更多还原