计算机视觉关键技术及其在通信工程中的应用

本文首先总结了计算机视觉领域的重要关键技术和典型算法模型,然后介绍了这些技术在通信工程领域内设备安装、施工验收、三维测量和天面核查等4种典型场景下的应用方案及实施效果,将为通信工程行业构建数字孪生网络提供有益探索。

Prospective controlled study on the effects of polyethylene glycol in capsule endoscopy

AIM:To prospectively confirm whether a small amount of polyethylene glycol(PEG)ingested after swallowing endoscopy capsule improves image quality and completion rate.METHODS:Forty-four consecutive patients referred to us for capsule endoscopy(CE)were randomized to two groups.All patients were restricted to clear fluids for 12 h before the examination.Patients in group A(22 cases)received no additional preparation,while those in group B(20 cases)ingested 500 mL of PEG within a 2 h period starting 30 min after swallowing the capsule.Clear fluids and meals were allowed 2 h and 4 h after capsule ingestion,respectively.Image quality was assessed as the percentage of visualized bowel surface area as follows:1:<25%;2:25%-49%;3:50%-74%;4:75%-89%;5:>90%.The small bowel record was divided into five segments by time,and the score for each segment was evaluated.All CE examinations were performed with the Pillcam SB capsule endoscopy sys-tem(Given Imaging Co.Ltd.,Yoqnem).RESULTS:This study ended in December 2009,because sample size was considered large enough.A total of 44 patients were enrolled.Two patients in group B were excluded from the analysis because small bowel images could not be obtained from these patients;one had a full stomach,while the other presented with a massive gastric bleed.Thus,22 patients from group A and 20 patients from group B completed the study.There was no significant difference in age(P=0.22),sex(P=0.31),and indication for CE.No significant adverse events occurred in any of the study patients.In group A,image quality deteriorated as the capsule progressed distally.However,in group B,image quality was maintained to the distal small bowel.In each of the five segments,the visibility score was significantly higher in group B than in group A(segment 1:4.3± 0.7vs 4.7±0.5,P=0.03;segment 2:4.2±0.9vs 4.8 ±0.4,P=0.01;segment 3:4.0±1.0 vs 4.6±0.7,P =0.04;segment 4:3.6±1.1 vs 4.5±0.6,P=0.003;segment 5:2.7±1.0vs 4.4±0.8,P=0.00004).Thus,the use of PEG during CE examination significantly improved image quality in all time segments,and this effect was more pronounced in the distal ileum.The completion rate to the cecum was not significantly different between groups A and B(81.8%vs 85.0%,P =0.89).There was no difference in the gastric transit time between groups(36.2±35.0 min vs 54.0±56.6 min,P=0.23),but the small bowel transit time was significantly longer in group A than in group B(246.0± 107.0 minvs 171.0±104.0 min,P=0.04).CONCLUSION:The ingestion of a small amount of PEG after the swallowing of an endoscopy capsule significantly improved CE image quality,but did not enhance the completion rate to the cecum.

Sonography of the small intestine

In the last two decades, there has been substantial development in the diagnostic possibilities for examining the small intestine. Compared with computerized tomography, magnetic resonance imaging, capsule endoscopy and double-balloon endoscopy, ultrasonography has the advantage of being cheap, portable, flexible and user-and patient-friendly, while at the same time providing the clinician with image data of high temporal and spatial resolution. The method has limitations with penetration in obesity and with intestinal air impairing image quality. The flexibility ultrasonography offers the examiner also implies that a systematic approach during scanning is needed. This paper reviews the basic scanning techniques and new modalities such as contrast-enhanced ultrasound, elastography, strain rate imaging, hydrosonography, allergosonography, endoscopic sonography and nutritional imaging, and the literature on disease-specific findings in the small intestine. Some of these methods have shown clinical benefit, while others are under research and development to establish their role in the diagnostic repertoire. However, along with improved overall image quality of new ultrasound scanners, these methodshave enabled more anatomical and physiological changes in the small intestine to be observed. Accordingly, ultrasound of the small intestine is an attractive clinical tool to study patients with a range of diseases.

Image Quality Improvement for Underwater Visual Inspections of Nuclear Power Plants

Visual inspection of the key components of nuclear power plants(NPPs)is important for NPP operation and maintenance. However,the underwater environment and existing radiation will lead to image degradation,thus making it difficult to identify surface defects. In this study,a method for improving the quality of underwater images is proposed.By analyzing the degradation characteristics of underwater detection image,the image enhancement technology is used to improve the color richness of the image,and then the improved dark channel prior(DCP)algorithm is used to restore it. By modifying the estimation formula of transmittance and background light,the correction of insufficient brightness in DCP restored image is realized. The proposed method is compared with other state-of-the-art methods. The results show that the proposed method can achieve higher scores and improve the image quality by correcting the color and restoring local details,thus effectively enhancing the reliability of visual inspection of NPPs.

Photodetection of the Quality on Internal Surface of Steel Pipe

In this paper,a photoelectric device is introduced,which is used in detecting the quality on internal surface of thin and long steel pipe.In this device,the CCTV lens is used for extract tile flaw information on internal surface of the pipe,and make IBM-PC/AT 486 computer as controlling and image processing system.By this instrument,the functions,such as the digital conversion of input information,image processing,classification of recognition and output display can be obtained.In the petroleum and chemical industry,by using this apparatus,we can detect the quality on internal surface of various metal pipes with real-time automatically.