IEEE Trans Med Imaging. 2018 Sep;37(9):2044-2059. doi: 10.1109/TMI.2018.2815013. Epub 2018 Mar 12.
The task of segmenting cell nuclei and cytoplasm in pap smear images is one of the most challenging tasks in automated cervix cytological analysis due to specifically the presence of overlapping cells. This paper introduces a multi-pass fast watershed-based method (MPFW) to segment both nucleus and cytoplasm from large cell masses of overlapping cervical cells in three watershed passes. The first pass locates the nuclei with barrier-based watershed on the gradient-based edge map of a pre-processed image. The next pass segments the isolated, touching, and partially overlapping cells with a watershed transform adapted to the cell shape and location. The final pass introduces mutual iterative watersheds separately applied to each nucleus in the largely overlapping clusters to estimate the cell shape. In MPFW, the line-shaped contours of the watershed cells are deformed with ellipse fitting and contour adjustment to give a better representation of cell shapes. The performance of the proposed method has been evaluated using synthetic, real extended depth-of-field, and multi-layers cervical cytology images provided by the first and second overlapping cervical cytology image segmentation challenges in ISBI 2014 and ISBI 2015. The experimental results demonstrate superior performance of the proposed MPFW in terms of segmentation accuracy, detection rate, and time complexity, compared with recent peer methods.
在自动化宫颈细胞学分析中，分割巴氏涂片图像中的细胞核和细胞质是最具挑战性的任务之一，特别是由于存在重叠细胞。本文提出了一种多遍快速分水岭算法（MPFW），通过三个分水岭传递，从重叠宫颈细胞的大细胞块中分割细胞核和细胞质。第一遍通过基于障碍的分水岭算法在预处理图像的基于梯度的边缘图上定位细胞核。下一遍通过适应细胞形状和位置的分水岭变换来分割孤立、接触和部分重叠的细胞。最后一遍分别对大重叠簇中的每个细胞核应用相互迭代的分水岭，以估计细胞形状。在 MPFW 中，使用椭圆拟合和轮廓调整来变形分水岭细胞的线状轮廓，以更好地表示细胞形状。所提出方法的性能已使用由 ISBI 2014 和 ISBI 2015 中第一个和第二个重叠宫颈细胞学图像分割挑战提供的合成、真实扩展景深和多层宫颈细胞学图像进行了评估。实验结果表明，与最近的同行方法相比，所提出的 MPFW 在分割准确性、检测率和时间复杂度方面具有优越的性能。
