为了解决采集图像时相机与旋转铣刀刀刃位置不确定的问题及提高图像处理的时效性,提出了一种基于机器视觉的铣刀磨损在机检测方法。根据结构相似性算法判断刀具图像质量,并引入图像采集间隔角度系数,确定了图像采集间隔角度与主轴转速...为了解决采集图像时相机与旋转铣刀刀刃位置不确定的问题及提高图像处理的时效性,提出了一种基于机器视觉的铣刀磨损在机检测方法。根据结构相似性算法判断刀具图像质量,并引入图像采集间隔角度系数,确定了图像采集间隔角度与主轴转速。采用加速段特征测试(Features from accelerated segment test,FAST)算法实现了对刀具磨损区域快速、准确地自适应裁剪。基于FAST特征点提出了自适应阈值分割方法,有效提取出磨损区域边缘。采用Hough变换和最小外接矩形法,实现了对主切削刃倾斜角度的校正,进而提取出磨损区域B区的平均宽度。最后开展了铣削试验,在16组试验中,计算值与真实值的最大、最小和平均误差分别为4.76%、0.91%、3.63%。试验结果表明,该方法可在主轴旋转时获取所有铣刀磨损区域的高质量图像,进而高效、准确地提取磨损参数。展开更多
Preoperative assessment of the liver volume and function of the remnant liver is a mandatory prerequisite before performing major hepatectomy. The aim of this work is to develop and test a software application for eva...Preoperative assessment of the liver volume and function of the remnant liver is a mandatory prerequisite before performing major hepatectomy. The aim of this work is to develop and test a software application for evaluation of the residual function of the liver prior to the intervention of the surgeons. For this purpose, a complete software platform consisting of three basic modules: liver volume segmentation, visualization, and virtual cutting, was developed and tested. Liver volume segmentation is based on a patient examination with non-contrast abdominal Computed Tomography (CT). The basis of the segmentation is a multiple seeded region growing algorithm adapted for use with CT images without contrast-enhancement. Virtual tumor resection is performed interactively by outlining the liver region on the CT images. The software application then processes the results to produce a three-dimensional (3D) image of the “resected” region. Finally, 3D rendering module provides possibility for easy and fast interpretation of the segmentation results. The visual outputs are accompanied with quantitative measures that further provide estimation of the residual liver function and based on them the surgeons could make a better decision. The developed system was tested and verified with twenty abdominal CT patient sets consisting of different numbers of tomographic images. Volumes, obtained by manual tracing of two surgeon experts, showed a mean relative difference of 4.5%. The application was used in a study that demonstrates the need and the added value of such a tool in practice and in education.展开更多
文摘为了解决采集图像时相机与旋转铣刀刀刃位置不确定的问题及提高图像处理的时效性,提出了一种基于机器视觉的铣刀磨损在机检测方法。根据结构相似性算法判断刀具图像质量,并引入图像采集间隔角度系数,确定了图像采集间隔角度与主轴转速。采用加速段特征测试(Features from accelerated segment test,FAST)算法实现了对刀具磨损区域快速、准确地自适应裁剪。基于FAST特征点提出了自适应阈值分割方法,有效提取出磨损区域边缘。采用Hough变换和最小外接矩形法,实现了对主切削刃倾斜角度的校正,进而提取出磨损区域B区的平均宽度。最后开展了铣削试验,在16组试验中,计算值与真实值的最大、最小和平均误差分别为4.76%、0.91%、3.63%。试验结果表明,该方法可在主轴旋转时获取所有铣刀磨损区域的高质量图像,进而高效、准确地提取磨损参数。
文摘Preoperative assessment of the liver volume and function of the remnant liver is a mandatory prerequisite before performing major hepatectomy. The aim of this work is to develop and test a software application for evaluation of the residual function of the liver prior to the intervention of the surgeons. For this purpose, a complete software platform consisting of three basic modules: liver volume segmentation, visualization, and virtual cutting, was developed and tested. Liver volume segmentation is based on a patient examination with non-contrast abdominal Computed Tomography (CT). The basis of the segmentation is a multiple seeded region growing algorithm adapted for use with CT images without contrast-enhancement. Virtual tumor resection is performed interactively by outlining the liver region on the CT images. The software application then processes the results to produce a three-dimensional (3D) image of the “resected” region. Finally, 3D rendering module provides possibility for easy and fast interpretation of the segmentation results. The visual outputs are accompanied with quantitative measures that further provide estimation of the residual liver function and based on them the surgeons could make a better decision. The developed system was tested and verified with twenty abdominal CT patient sets consisting of different numbers of tomographic images. Volumes, obtained by manual tracing of two surgeon experts, showed a mean relative difference of 4.5%. The application was used in a study that demonstrates the need and the added value of such a tool in practice and in education.
