• Title/Summary/Keyword: Image Quality Assessment

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A Study on Nutritional Status and Dietary Quality of University Students by Body Image (대학생의 체형인식에 따른 영양소 섭취 상태 및 식사의 질 평가)

  • Yeon, Jee-Young;Hong, Seung-Hee;Bae, Yun-Jung
    • Korean Journal of Community Nutrition
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    • v.17 no.5
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    • pp.543-554
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    • 2012
  • This study was performed to investigate the satisfaction of body image, dietary habits, nutrition intake and dietary quality according to body image of university students (n = 290). The subjects (male = 178, female = 112) were classified to lean, normal and overweight/fat groups according to body image. The weight, body fat and body mass index (BMI) was significantly higher in the students who recognized their body image as 'overweight/fat'. The satisfaction of body image, interest of weight control and experience of weight control were significantly higher in students who recognized their body image as 'normal' in both the male and female subjects. The intakes of nutrients, dietary habits and life styles were not different according to body image. In the male subjects, the niacin intake density, the nutrient adequacy ratio (NAR) of vitamin B1 and the dietary diversity score (DDS) in the students who recognized their body image as 'overweight/fat' were significantly lower than in students who recognized their body image as 'normal' and 'lean'. In female subjects, no significant differences in nutrient intakes, NAR, MAR and DDS were observed according to body image. Future studies with a larger sample size are needed for further assessment of the relationship between nutritional status/diet quality and body image in university students.

Blind Quality Metric via Measurement of Contrast, Texture, and Colour in Night-Time Scenario

  • Xiao, Shuyan;Tao, Weige;Wang, Yu;Jiang, Ye;Qian, Minqian.
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.15 no.11
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    • pp.4043-4064
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    • 2021
  • Night-time image quality evaluation is an urgent requirement in visual inspection. The lighting environment of night-time results in low brightness, low contrast, loss of detailed information, and colour dissonance of image, which remains a daunting task of delicately evaluating the image quality at night. A new blind quality assessment metric is presented for realistic night-time scenario through a comprehensive consideration of contrast, texture, and colour in this article. To be specific, image blocks' color-gray-difference (CGD) histogram that represents contrast features is computed at first. Next, texture features that are measured by the mean subtracted contrast normalized (MSCN)-weighted local binary pattern (LBP) histogram are calculated. Then statistical features in Lαβ colour space are detected. Finally, the quality prediction model is conducted by the support vector regression (SVR) based on extracted contrast, texture, and colour features. Experiments conducted on NNID, CCRIQ, LIVE-CH, and CID2013 databases indicate that the proposed metric is superior to the compared BIQA metrics.

Image quality assessment of pre-processed and post-processed digital panoramic radiographs in paediatric patients with mixed dentition

  • Suryani, Isti Rahayu;Villegas, Natalia Salvo;Shujaat, Sohaib;De Grauwe, Annelore;Azhari, Azhari;Sitam, Suhardjo;Jacobs, Reinhilde
    • Imaging Science in Dentistry
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    • v.48 no.4
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    • pp.261-268
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    • 2018
  • Purpose: To determine the impact of an image processing technique on diagnostic accuracy of digital panoramic radiographs for the assessment of anatomical structures in paediatric patients with mixed dentition. Materials and Methods: The study consisted of 50 digital panoramic radiographs of children aged from 6 to 12 years, which were later on processed using a dedicated image processing method. A modified clinical image quality evaluation chart was used to evaluate the diagnostic accuracy of anatomical structures in maxillary and mandibular anterior and maxillary premolar region of processed images. Results: A statistically significant difference was observed between pre and post-processed evaluation of anatomical structures(P<0.05) in the maxillary and mandibular anterior region. The anterior region was found to be more accurate in post-processed images. No significant difference was observed in the maxillary premolar region (P>0.05). The Inter-observer and intra-observer reliability of both pre and post processed images were excellent (>0.82) for anterior region and good (>0.63) for premolar region. Conclusion: The application of image processing technique in digital panoramic radiography can be considered a reliable method for improving the quality of anatomical structures in paediatric patients with mixed dentition.

Object Edge-based Image Generation Technique for Constructing Large-scale Image Datasets (대형 이미지 데이터셋 구축을 위한 객체 엣지 기반 이미지 생성 기법)

  • Ju-Hyeok Lee;Mi-Hui Kim
    • Journal of IKEEE
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    • v.27 no.3
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    • pp.280-287
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    • 2023
  • Deep learning advancements can solve computer vision problems, but large-scale datasets are necessary for high accuracy. In this paper, we propose an image generation technique using object bounding boxes and image edge components. The object bounding boxes are extracted from the images through object detection, and image edge components are used as input values for the image generation model to create new image data. As results of experiments, the images generated by the proposed method demonstrated similar image quality to the source images in the image quality assessment, and also exhibited good performance during the deep learning training process.

Quantitative Evaluation of Image Quality using Automatic Exposure Control & Sensitivity in the Digital Chest Image (디지털 흉부영상에서 자동노출제어 및 감도변화를 이용한 영상품질의 정량적인 평가)

  • Lee, Jin-Soo;Ko, Seong-Jin;Kang, Se-Sik;Kim, Jung-Hoon;Kim, Dong-Hyun;Kim, Changsoo
    • The Journal of the Korea Contents Association
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    • v.13 no.8
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    • pp.275-283
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    • 2013
  • The patient radiation dose is different depending on selection of Ion chamber when taking Chest PA which using AEC. In this paper, we studied acquiring the best diagnostic images according to selection of Ion chamber on AEC mode as well as minimizing patient radiation dose. Experimental methods were selection of Ion chamber and change of sensitivity under the same conditions as Chest PA projection. At AEC mode, two upper ion chambers sensors and one lower ion chamber sensor were divided into 7 cases according to selection of on/off. after measuring five times respectively, we obtained average value and calculated exposure dose. Image assessment was done with measured Modulation Transfer Function, Peak Signal to Noise Ratio, Root Mean Square, Signal to Noise Ratio, Contrast to Noise Ratio, Mean to Standard deviation Ratio respectively. In exposure assessment results, selection of two upper chambers was the lowest. In resolution assessment results, image of two upper chambers had the second high spatial frequency at sensitivity at 625(High) was 1.343 lp/mm. RMS value of image selecting two upper chambers was low secondly. SNR, CNR, MSR were the high value secondly. As the sensitivity was increased, radiation dose was decreased but better image could be obtained on image quality. In order to obtain the best medical images while minimizing the dose, usage of two upper ion chambers is considered to be clinically useful at sensitivity 625(High).

Fingerprint Image Quality Assessment for On-line Fingerprint Recognition (온라인 지문 인식 시스템을 위한 지문 품질 측정)

  • Lee, Sang-Hoon
    • Journal of the Institute of Electronics Engineers of Korea SP
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    • v.47 no.2
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    • pp.77-85
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    • 2010
  • Fingerprint image quality checking is one of the most important issues in on-line fingerprint recognition because the recognition performance is largely affected by the quality of fingerprint images. In the past, many related fingerprint quality checking methods have typically considered the local quality of fingerprint. However, It is necessary to estimate the global quality of fingerprint to judge whether the fingerprint can be used or not in on-line recognition systems. Therefore, in this paper, we propose both local and global-based methods to calculate the fingerprint quality. Local fingerprint quality checking algorithm considers both the condition of the input fingerprints and orientation estimation errors. The 2D gradients of the fingerprint images were first separated into two sets of 1D gradients. Then,the shapes of the PDFs(Probability Density Functions) of these gradients were measured in order to determine fingerprint quality. And global fingerprint quality checking method uses neural network to estimate the global fingerprint quality based on local quality values. We also analyze the matching performance using FVC2002 database. Experimental results showed that proposed quality check method has better matching performance than NFIQ(NIST Fingerprint Image Quality) method.

Evaluating Accuracy of Algorithms Providing Subsurface Properties Using Full-Reference Image Quality Assessment (완전 참조 이미지 품질 평가를 이용한 지하 매질 물성 정보 도출 알고리즘의 정확성 평가)

  • Choi, Seungpyo;Jun, Hyunggu;Shin, Sungryul;Chung, Wookeen
    • Geophysics and Geophysical Exploration
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    • v.24 no.1
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    • pp.6-19
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    • 2021
  • Subsurface physical properties can be obtained and imaged by seismic exploration, and various algorithms have been developed for this purpose. In this regard, root mean square error (RMSE) has been widely used to quantitatively evaluate the accuracy of the developed algorithms. Although RMSE has the advantage of being numerically simple, it has limitations in assessing structural similarity. To supplement this, full-reference image quality assessment (FR-IQA) techniques, which reflect the human visual system, are being investigated. Therefore, we selected six FR-IQA techniques that could evaluate the obtained physical properties. In this paper, we used the full-waveform inversion, because the algorithm can provide the physical properties. The inversion results were applied to the six selected FR-IQA techniques using three benchmark models. Using salt models, it was confirmed that the inversion results were not satisfactory in some aspects, but the value of RMSE decreased. On the other hand, some FR-IQA techniques could definitely improve the evaluation.

Assessment of Dose and Image Quality according to the Change of Distance from Source to Image Receptor and the Examination Posture during the Skull Lateral Radiography (두부 측 방향 방사선검사 시 선원 영상수용체간 거리와 검사 자세 변화가 선량과 영상품질에 미치는 영향)

  • Eun-Hye, Kim;Young-Cheol, Joo;Han-Yong, Kim;Dong-Hwan, Kim
    • Journal of radiological science and technology
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    • v.45 no.6
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    • pp.483-489
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    • 2022
  • This study proposes a new skull lateral examination, and provides an improved examination environment for patients and radiologists. The study was divided into three groups. One group was divided into the SID (source to image receptor distance) 110 ㎝ and 180 ㎝ in the skull lateral posture, the other group The other group was divided into an position in contact with the detector and an position without contact with the detector, and the other group was divided into male and female groups, considering that the difference in shoulder width between adult males and females would affect the dose and image quality. For dose evaluation, the ESD (entrance surface dose) was measured at the EAM (external auditory meatus), and the conditions were applied equally at 70 ㎸p, 200 ㎃, and 10 ㎃s. For image quality evaluation, SNR (signal to noise ratio) and CNR (contrast to noise ratio) were measured in frontal sinus, EAM, and sella turcica. As a result of ESD comparison, when sid 110 ㎝ to sid 180 ㎝ was changed among the three groups, ESD values decreased the most to 729.18±4.62 μ㏉ and 224.18±0.74 μ㏉ at 180 ㎝ (p<0.01). The values of SNR and CNR were statistically significant (p<0.01), but there was no qualitative difference. This shows that when the SID is 180 ㎝, it is possible to reduce the dose without lowering the image quality. So, It is suggested that the SID 180 ㎝ is used without contacting the detector when examining the skull lateral.

Bridge Inspection and condition assessment using Unmanned Aerial Vehicles (UAVs): Major challenges and solutions from a practical perspective

  • Jung, Hyung-Jo;Lee, Jin-Hwan;Yoon, Sungsik;Kim, In-Ho
    • Smart Structures and Systems
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    • v.24 no.5
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    • pp.669-681
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    • 2019
  • Bridge collapses may deliver a huge impact on our society in a very negative way. Out of many reasons why bridges collapse, poor maintenance is becoming a main contributing factor to many recent collapses. Furthermore, the aging of bridges is able to make the situation much worse. In order to prevent this unwanted event, it is indispensable to conduct continuous bridge monitoring and timely maintenance. Visual inspection is the most widely used method, but it is heavily dependent on the experience of the inspectors. It is also time-consuming, labor-intensive, costly, disruptive, and even unsafe for the inspectors. In order to address its limitations, in recent years increasing interests have been paid to the use of unmanned aerial vehicles (UAVs), which is expected to make the inspection process safer, faster and more cost-effective. In addition, it can cover the area where it is too hard to reach by inspectors. However, this strategy is still in a primitive stage because there are many things to be addressed for real implementation. In this paper, a typical procedure of bridge inspection using UAVs consisting of three phases (i.e., pre-inspection, inspection, and post-inspection phases) and the detailed tasks by phase are described. Also, three major challenges, which are related to a UAV's flight, image data acquisition, and damage identification, respectively, are identified from a practical perspective (e.g., localization of a UAV under the bridge, high-quality image capture, etc.) and their possible solutions are discussed by examining recently developed or currently developing techniques such as the graph-based localization algorithm, and the image quality assessment and enhancement strategy. In particular, deep learning based algorithms such as R-CNN and Mask R-CNN for classifying, localizing and quantifying several damage types (e.g., cracks, corrosion, spalling, efflorescence, etc.) in an automatic manner are discussed. This strategy is based on a huge amount of image data obtained from unmanned inspection equipment consisting of the UAV and imaging devices (vision and IR cameras).

A HIERARCHICAL APPROACH TO HIGH-RESOLUTION HYPERSPECTRAL IMAGE CLASSIFICATION OF LITTLE MIAMI RIVER WATERSHED FOR ENVIRONMENTAL MODELING

  • Heo, Joon;Troyer, Michael;Lee, Jung-Bin;Kim, Woo-Sun
    • Proceedings of the KSRS Conference
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    • v.2
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    • pp.647-650
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    • 2006
  • Compact Airborne Spectrographic Imager (CASI) hyperspectral imagery was acquired over the Little Miami River Watershed (1756 square miles) in Ohio, U.S.A., which is one of the largest hyperspectral image acquisition. For the development of a 4m-resolution land cover dataset, a hierarchical approach was employed using two different classification algorithms: 'Image Object Segmentation' for level-1 and 'Spectral Angle Mapper' for level-2. This classification scheme was developed to overcome the spectral inseparability of urban and rural features and to deal with radiometric distortions due to cross-track illumination. The land cover class members were lentic, lotic, forest, corn, soybean, wheat, dry herbaceous, grass, urban barren, rural barren, urban/built, and unclassified. The final phase of processing was completed after an extensive Quality Assurance and Quality Control (QA/QC) phase. With respect to the eleven land cover class members, the overall accuracy with a total of 902 reference points was 83.9% at 4m resolution. The dataset is available for public research, and applications of this product will represent an improvement over more commonly utilized data of coarser spatial resolution such as National Land Cover Data (NLCD).

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