图 书 馆
具有平均场推断的密集随机场的改进初始化和高斯混合成对项Improved Initialisation and Gaussian Mixture Pairwise Terms for Dense Random Fields with Mean-field Inference |
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| 课程网址: | http://videolectures.net/bmvc2012_vineet_mean_field/ |
| 主讲教师: | Vibhav Vineet |
| 开课单位: | 牛津布鲁克斯大学 |
| 开课时间: | 2012-10-09 |
| 课程语种: | 英语 |
| 中文简介: |  |
| 课程简介: | Recently, Krahenbuhl and Koltun proposed an efficient inference method for densely connected pairwise random fields using the mean-field approximation for a Conditional Random Field (CRF). However, they restrict their pairwise weights to take the form of a weighted combination of Gaussian kernels where each Gaussian component is allowed to take only zero mean, and can only be rescaled by a single value for each label pair. Further, their method is sensitive to initialization. In this paper, we propose methods to alleviate these issues. First, we propose a hierarchical mean-field approach where labelling from the coarser level is propagated to the finer level for better initialisation. Further, we use SIFT-flow based label transfer to provide a good initial condition at the coarsest level. Second, we allow our approach to take general Gaussian pairwise weights, where we learn the mean, the co-variance matrix, and the mixing co-efficient for every mixture component. We propose a variation of Expectation Maximization (EM) for piecewise learning of the parameters of the mixture model determined by the maximum likelihood function. Finally, we demonstrate the efficiency and accuracy offered by our method for object class segmentation problems on two challenging datasets: PascalVOC-10 segmentation and CamVid datasets. We show that we are able to achieve state of the art performance on the CamVid dataset, and an almost 3% improvement on the PascalVOC- 10 dataset compared to baseline graph-cut and mean-field methods, while also reducing the inference time by almost a factor of 3 compared to graph-cuts based methods. |
| 关 键 词: | 有效的推理方法; 条件随机场; 图切割 |
| 课程来源: | 视频讲座网 |
| 最后编审: | 2020-09-28：heyf |
| 阅读次数: | 117 |