乳腺钼靶X线图像中乳腺区域的分割可以帮助对图像进行深入分析和处理，从而提高乳腺疾病的诊断准确率。提出一种能有效提取乳腺区域的算法。算法分析了乳腺钼靶X线图像等值面面积变化不连续的特征并将其用于分割阈值的精确计算。该算法使用基于扫描线的方法来获得含乳腺区域的连通区域，比种子填充法效率更高。为了获得更纯粹的乳腺区域，通过一些精细地处理对乳腺区域相连的未曝光图像边框作了剥离。实验结果表明算法在乳腺区域分割的精度和执行效率上都有更好的表现。

Breast region extraction of mammogram is a crucial step for further analysis and processing, and can improve diagnosis accuracy of galactophore diseases. An efficient algorithm of automatically extracting breast region is proposed. The discontinuity of the variety of areas of the isosurfaces is explored and used for computing the accurate segmentation threshold. Then the connected region containing the breast region is extracted by using a scan line based method, which is more efficient than seed-filling based methods. In order to obtain more pure breast region, the unexposed borders of the image connected to the breast region are also removed through a few refinement procedures. Experimental results show that the method has good performances both on the accuracy of breast region segmentation and executing speed.