Conditional random field with the multi-granular contextual information for pixel labeling

2016 ◽  
Vol 76 (7) ◽  
pp. 9169-9194
Author(s):  
Jie Zhao ◽  
Gang Xie ◽  
Jiwan Han
Author(s):  
Weihao Li ◽  
Michael Ying Yang

In this paper we explore semantic segmentation of man-made scenes using fully connected conditional random field (CRF). Images of man-made scenes display strong contextual dependencies in the spatial structures. Fully connected CRFs can model long-range connections within the image of man-made scenes and make use of contextual information of scene structures. The pairwise edge potentials of fully connected CRF models are defined by a linear combination of Gaussian kernels. Using filter-based mean field algorithm, the inference is very efficient. Our experimental results demonstrate that fully connected CRF performs better than previous state-of-the-art approaches on both eTRIMS dataset and LabelMeFacade dataset.


2009 ◽  
Vol 2 ◽  
Author(s):  
Asif Ekbal ◽  
Sivaji Bandyopadhyay

This paper describes the development of Named Entity Recognition (NER) systems for two leading Indian languages, namely Bengali and Hindi, using the Conditional Random Field (CRF) framework. The system makes use of different types of contextual information along with a variety of features that are helpful in predicting the different named entity (NE) classes. This set of features includes language independent as well as language dependent components. We have used the annotated corpora of 122,467 tokens for Bengali and 502,974 tokens for Hindi tagged with a tag set of twelve different NE classes, defined as part of the IJCNLP-08 NER Shared Task for South and South East Asian Languages (SSEAL). We have considered only the tags that denote person names, location names, organization names, number expressions, time expressions and measurement expressions. A number of experiments have been carried out in order to find out the most suitable features for NER in Bengali and Hindi. The system has been tested with the gold standard test sets of 35K for Bengali and 50K tokens for Hindi. Evaluation results in overall f-score values of 81.15% for Bengali and 78.29% for Hindi for the test sets. 10-fold cross validation tests yield f-score values of 83.89% for Bengali and 80.93% for Hindi. ANOVA analysis is performed to show that the performance improvement due to the use of language dependent features is statistically significant.


Author(s):  
Laxmi Math ◽  
Ruksar Fatima

Objective: The objective is to provide a precise segmentation technique based on ACRF which can handle the variations between major and minor vessels and reduces the interference present in the model due to over fitting and can provide a high-quality reconstructed image. Therefore, a robust method with statistical properties needs to be presented to enhance the performance of the model. Moreover, a statistical framework is required to classify images precisely. Methods: Adaptive Conditional Random Field (ACRF) model to detect DR disease in early stages. Here, major vessel potentials and minor vessel potential features are extracted which in precise segmentation of vessel and non-vessel regions. This feature enhances the efficiency of the model. These major vessel and minor vessel potential features rebuild the retinal vasculature parts precisely and help to capture the contextual information present in the ground truth and label images. This method utilizes an ACRF model to reduce interference and computation complexity. Here, two efficient features are extracted to segment fundus images efficiently such as major vessel potentials and minor vessel potentials. The proposed ACRF model can provide the design patterns for both input images and labels with the help of major vessel potentials, unlike state-of-art-techniques which provide patterns for only labels and model the contextual information only in labels which is very essential while performing vessel segmentation Results: The performance results are tested on the DRIVE dataset. Experimental results verify the superiority of the proposed vessel segmentation technique based on the ACRF model in terms of accuracy, sensitivity, specificity, and F1measure and segmentation quality. Conclusion: A highly efficient vessel segmentation technique is evaluated to describe major and minor vessel regions efficiently based on the ACRF to recognize DR in early stages and to ensure an effective diagnosis using eye fundus images. The segmentation process decomposes input images into RGB components through histogram labels based on the proposed ACRF model. Here, the Gabor filtering approach is used for pre-processing and predicting parameters. The proposed segmentation method can provide the smooth boundaries of minor and major vessel regions. The proposed ACRF model can provide the design patterns for both input images and labels with the help of major vessel potentials, unlike state-of-art-techniques which provide patterns for only labels and model the contextual information only in labels.


Author(s):  
Weihao Li ◽  
Michael Ying Yang

In this paper we explore semantic segmentation of man-made scenes using fully connected conditional random field (CRF). Images of man-made scenes display strong contextual dependencies in the spatial structures. Fully connected CRFs can model long-range connections within the image of man-made scenes and make use of contextual information of scene structures. The pairwise edge potentials of fully connected CRF models are defined by a linear combination of Gaussian kernels. Using filter-based mean field algorithm, the inference is very efficient. Our experimental results demonstrate that fully connected CRF performs better than previous state-of-the-art approaches on both eTRIMS dataset and LabelMeFacade dataset.


Symmetry ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 251
Author(s):  
Yan Yan ◽  
Faguo Zhou ◽  
Yifan Ge ◽  
Cheng Liu ◽  
Jingwu Feng

With the spread of mobile applications and online interactive platforms, the number of user reviews are increasing explosively and becoming one of the most important ways for users to voice opinions. Opinion target extraction and opinion word extraction are two key procedures used to determine the helpfulness of reviews. In this paper, we implement a system to extract “opinion target:opinion word” pairs based on the Conditional Random Field (CRF). Firstly, we used the CRF model to extract opinion targets and opinion words, then combined these into pairs in order. In addition, Node.js was used to build a visualization system to display “opinion target:opinion word” pairs. In order to verify the effectiveness of the system, experiments were conducted on the Laptop and Restaurant datasets of SemEval-2014-task4, and the accuracy of the F value extracted by the model reached 86% and 90%, respectively. All the code and datasets for this experiment are available on GitHub.


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