Two-dimensional Computer Vision Research Articles

Triplet Siamese Network Model for Lithium-ion Battery Defects Classification Using Few-shot Learning Approach

In this paper, we propose a triplet siamese model for lithium-ion battery defects classification. It is a difficult task to detect the surface defects of lithium-ion batteries with stainless steel surface. The lack of three-dimensional information and the lack of marker datasets due to reflections prevent two-dimensional computer vision detection methods from meeting classification needs. In this work, the multiple exposure structured light method is utilized to obtain the three-dimensional shape of a lithium-ion battery with a stainless steel surface. The defect point cloud with three-dimensional information is obtained by this method, and then the 3D information of the defect point cloud is converted into grayscale information, and the grayscale image is used as the target domain data of the triplet siamese network. The public dataset MiniImageNet is utilized as the training data of the triplet siamese network model. The accuracies of the experimental results are 88.9%, 95.6%, and 97.8% for 1-shot, 5-shot, and 10-shot respectively. This result proves that our method can be used for lithium-ion battery defect detection.

Facial Anthropometric Measurements and Photographs — An Interdisciplinary Study

In recent years, automatic facial analysis has attracted much interest among computer science researchers in the healthcare and computer vision fields studying facial anthropometric measurements using photographs. However, to date, there have been no healthcare or computer vision publications that use standardized photographs to differentiate features between sub-ethnic groups by leveraging the power of machine learning on two-dimensional computer vision benchmark data sets (2D CVBDs). Thus, the present work is an interdisciplinary study at the interface of healthcare and computer vision fields that attempts to fill this literature gap where we explore the use of machine learning on 2,789 photographs from eleven 2D CVBDs to identify k top discriminative features in major and sub-ethnic groups. These features are ranked based on information gain values and p-values. We also provide a comprehensive analysis of using information-gain-based and p-value-based features. Our machine learning model achieves an accuracy of 96-99%, and our findings reveal that information-gain-based features have the upper hand over p-value-based features. The top three information-gain-based features in sub-ethnic groups are: dn (distance from the tip of the nose to the center of the mouth), hf (face height) and wn (nose width), while the top three information-gain-based features in major ethnic groups are: de (distance between the inner corners of the eyelids), hf and dn . These results are then compared to the results obtained using standard deep learning techniques such as OxfordNet (VGG16), Residual Networks (ResNet50), and Inception-V3, where accuracy of 90-94% was seen. We hope that these findings will lead to future collaboration between computer vision and healthcare researchers studying facial anthropometric measurement studies.

An optimized phase-shifting algorithm for depth image acquisition

As developing science and technology, traditional two-dimensional computer vision cannot meet the people’s needs for the three-dimensional recognition, and the depth information of objects are required by more and more applications. Recently, structured light has become one of the core techniques of depth acquisition. The main idea of the approach is first projecting pre-designed pattern onto objects, then capturing an image and processing further. In a structured light system, the phase-shifting algorithm, which is a depth acquiring algorithm for sinusoidal pattern, is discussed in this paper, and is argued that its performance weakness for applying in the real time environments. Then we propose the performance optimization on its phase wrapping step and phase unwrapping step, respectively. Finally, we compare acquiring results and advantages as well as disadvantages of them by experiments results. Experiments show that the optimized phase-shifting algorithm is 4.6× faster than the original one with the ignorable errors.