Abstract: The outline of breast contains very important information. It plays a very important role in image orientation and comparative analysis, to a certain extent, affects their performance. By analyzing the characteristics of breast X-ray images, the method automatic extracting breast contour based on monotonic decline curve model is proposed. The breast is determined on which side of the image. If it is on the right side, it will be mirrored to left. The model is applied to extract points of the breast contour. Then the contour point on the longest decreasing curve is chosen as base point to find true contour points on other scan lines. False contour is found out and arc model is used to fit true contour. The whole breast contour is extracted correctly.

Key words: breast X-ray image, monotonic decline curve model, breast contour extraction

摘要： 乳房外轮廓包含非常重要的信息，在图像定位、对比分析中起着非常重要的作用，在一定程度上影响着乳腺图像对比分析技术的性能。通过分析乳腺X线图像的特点，判别图像为左乳图像还是右乳图像，若是右乳图像则做水平镜像处理；应用单调下降曲线模型提取乳房轮廓点；选择最长下降曲线段上的轮廓点为基准点，分别向上和向下逐行修正其他扫描线上的轮廓点；判别伪轮廓曲线段，采用圆弧模型拟合正确的轮廓线，从而提取出完整的乳房轮廓线。

关键词: 乳腺X线图像, 单调下降曲线模型, 轮廓线提取