• Title/Summary/Keyword: image assessment

Search Result 1,134, Processing Time 0.025 seconds

Study on Measuring Geometrical Modification of Document Image in Scanning Process (스캐닝 과정에서 발생하는 전자문서의 기하학적 변형감지에 관한 연구)

  • Oh, Dong-Yeol;Oh, Hae-Seok;Rhew, Sung-Yul
    • Journal of the Korea Academia-Industrial cooperation Society
    • /
    • v.10 no.8
    • /
    • pp.1869-1876
    • /
    • 2009
  • Scanner which is a kind of optical devices is used to convert paper documents into document image files. The assessment of scanned document image is performed to check if there are any modification on document image files in scanning process. In assessment of scanned documents, user checks the degree of skew, noise, folded state and etc This paper proposed to how to measure geometrical modifications of document image in scanning process. In this study, we check the degree of modification in document image file by image processing and we compare the evaluation value which means the degree of modification in each items with OCR success ratio in a document image file. To analyse the correlation between OCR success ratio and the evaluation value which means the degree of modification in each items, we apply Pearson Correlation Coefficient and calculate weight value for each items to score total evaluation value of image modification degrees on a image file. The document image which has high rating score by proposed method also has high OCR success ratio.

Analysis of UAV-based Multispectral Reflectance Variability for Agriculture Monitoring (농업관측을 위한 다중분광 무인기 반사율 변동성 분석)

  • Ahn, Ho-yong;Na, Sang-il;Park, Chan-won;Hong, Suk-young;So, Kyu-ho;Lee, Kyung-do
    • Korean Journal of Remote Sensing
    • /
    • v.36 no.6_1
    • /
    • pp.1379-1391
    • /
    • 2020
  • UAV in the agricultural application are capable of collecting ultra-high resolution image. It is possible to obtain timeliness images for phenological phases of the crop. However, the UAV uses a variety of sensors and multi-temporal images according to the environment. Therefore, it is essential to use normalized image data for time series image application for crop monitoring. This study analyzed the variability of UAV reflectance and vegetation index according to Aviation Image Making Environment to utilize the UAV multispectral image for agricultural monitoring time series. The variability of the reflectance according to environmental factors such as altitude, direction, time, and cloud was very large, ranging from 8% to 11%, but the vegetation index variability was stable, ranging from 1% to 5%. This phenomenon is believed to have various causes such as the characteristics of the UAV multispectral sensor and the normalization of the post-processing program. In order to utilize the time series of unmanned aerial vehicles, it is recommended to use the same ratio function as the vegetation index, and it is recommended to minimize the variability of time series images by setting the same time, altitude and direction as possible.

Evaluation of Color Reproduction Characteristics of TFT-LCD and AMOLED for Mobile Phone (모바일폰용 TFT-LCD와 AMOLED의 색재현성 평가)

  • Park, Tae-Yong;Lee, Cheol-Hee;Ha, Yeong-Ho
    • Journal of the Institute of Electronics Engineers of Korea SP
    • /
    • v.45 no.1
    • /
    • pp.29-37
    • /
    • 2008
  • With the rapid development of display technology as well as the diversity of display, image quality assessment plays an important role in display color reproduction. The image quality has described by objective evaluation based on the physical measured data, such as contrast ratio, color reproduction range, color temperature, and gamma characteristics, etc., however, the final judgement is achieved by perceptual quality assessment of observers. Therefore, it is necessary to investigate the relationship between physical performance of display and perceptual image quality. Thus, in order to evaluate objectively the color reproduction characteristics of two mobile displays, TFT-LCD and AMOLED, we measured the darkroom contrast ratio of full screen, luminance and color temperature of full-screen white, full-screen gray and color linearity, tone reproduction of color scales for each RGB primary, and color reproduction range. Then the pair-wise comparison is implemented for image experts and naive observers not only to judge their preference on principal evaluation attributes but also to subjectively describe perceived image quality. Through two evaluation processes, we derived the objective bases that can prove the results of subjective image quality assessment by interconnecting physical factors that have influence on observers' preference judgements. Finally, this paper provided important information for improving the image quality and increasing preference from an observer's point of view.

Unleashing the Potential of Vision Transformer for Automated Bone Age Assessment in Hand X-rays (자동 뼈 연령 평가를 위한 비전 트랜스포머와 손 X 선 영상 분석)

  • Kyunghee Jung;Sammy Yap Xiang Bang;Nguyen Duc Toan;Hyunseung Choo
    • Proceedings of the Korea Information Processing Society Conference
    • /
    • 2023.05a
    • /
    • pp.687-688
    • /
    • 2023
  • Bone age assessment is a crucial task in pediatric radiology for assessing growth and development in children. In this paper, we explore the potential of Vision Transformer, a state-of-the-art deep learning model, for bone age assessment using X-ray images. We generate heatmap outputs using a pre-trained Vision Transformer model on a publicly available dataset of hand X-ray images and show that the model tends to focus on the overall hand and only the bone part of the image, indicating its potential for accurately identifying the regions of interest for bone age assessment without the need for pre-processing to remove background noise. We also suggest two methods for extracting the region of interest from the heatmap output. Our study suggests that Vision Transformer holds great potential for bone age assessment using X-ray images, as it can provide accurate and interpretable output that may assist radiologists in identifying potential abnormalities or areas of interest in the X-ray image.

Correlation Research between Objective and Subjective Image Quality Assessment (객관적 화질 평가와 주관적 화질 평가의 상관관계 연구)

  • Park, Hyung-Ju;Har, Dong-Hwan
    • The Journal of the Korea Contents Association
    • /
    • v.11 no.8
    • /
    • pp.68-76
    • /
    • 2011
  • Due to the high interests of image quality by consumers, the concerned market becomes more heated. Recent digital camera development tendency shows to perform the higher image quality to meet consumers demand of quality satisfaction. However it is hard to confirm that development of objective image quality performance means positive subjective image quality preference. And also, we cannot find out the previous researches concerned on correlation between objective and subjective image quality comparison. Therefore, it is necessary to analyze the consumers preferred images based on objective image quality performance. Throughout this paper, we analyze statistical correlation between the objective and subjective image quality assessment methods by using ISO standards. In these results, we try to find attributes that enhance image quality. We suggest not only to analyze and reflect on customers' preferences, but also to pursue the high quality image performance practically. We expect the results of this paper to positively influence product development.

Quality Assessment of Images Projected Using Multiple Projectors

  • Kakli, Muhammad Umer;Qureshi, Hassaan Saadat;Khan, Muhammad Murtaza;Hafiz, Rehan;Cho, Yongju;Park, Unsang
    • KSII Transactions on Internet and Information Systems (TIIS)
    • /
    • v.9 no.6
    • /
    • pp.2230-2250
    • /
    • 2015
  • Multiple projectors with partially overlapping regions can be used to project a seamless image on a large projection surface. With the advent of high-resolution photography, such systems are gaining popularity. Experts set up such projection systems by subjectively identifying the types of errors induced by the system in the projected images and rectifying them by optimizing (correcting) the parameters associated with the system. This requires substantial time and effort, thus making it difficult to set up such systems. Moreover, comparing the performance of different multi-projector display (MPD) systems becomes difficult because of the subjective nature of evaluation. In this work, we present a framework to quantitatively determine the quality of an MPD system and any image projected using such a system. We have divided the quality assessment into geometric and photometric qualities. For geometric quality assessment, we use Feature Similarity Index (FSIM) and distance-based Scale Invariant Feature Transform (SIFT). For photometric quality assessment, we propose to use a measure incorporating Spectral Angle Mapper (SAM), Intensity Magnitude Ratio (IMR) and Perceptual Color Difference (ΔE). We have tested the proposed framework and demonstrated that it provides an acceptable method for both quantitative evaluation of MPD systems and estimation of the perceptual quality of any image projected by them.

2-Step Structural Damage Analysis Based on Foundation Model for Structural Condition Assessment (시설물 상태평가를 위한 파운데이션 모델 기반 2-Step 시설물 손상 분석)

  • Hyunsoo Park;Hwiyoung Kim ;Dongki Chung
    • Korean Journal of Remote Sensing
    • /
    • v.39 no.5_1
    • /
    • pp.621-635
    • /
    • 2023
  • The assessment of structural condition is a crucial process for evaluating its usability and determining the diagnostic cycle. The currently employed manpower-based methods suffer from issues related to safety, efficiency, and objectivity. To address these concerns, research based on deep learning using images is being conducted. However, acquiring structural damage data is challenging, making it difficult to construct a substantial amount of training data, thus limiting the effectiveness of deep learning-based condition assessment. In this study, we propose a foundation model-based 2-step structural damage analysis to overcome the lack of training data in image-based structural condition assessments. We subdivided the elements of structural condition assessment into instantiation and quantification. In the quantification step, we applied a foundation model for image segmentation. Our method demonstrated a 10%-point increase in mean intersection over union compared to conventional image segmentation techniques, with a notable 40%-point improvement in the case of rebar exposure. We anticipate that our proposed approach will enhance performance in domains where acquiring training data is challenging.

Uncertainty assessment for a towed underwater stereo PIV system by uniform flow measurement

  • Han, Bum Woo;Seo, Jeonghwa;Lee, Seung Jae;Seol, Dong Myung;Rhee, Shin Hyung
    • International Journal of Naval Architecture and Ocean Engineering
    • /
    • v.10 no.5
    • /
    • pp.596-608
    • /
    • 2018
  • The present study aims to assess test uncertainty assessment method of nominal wake field measurement by a Stereoscopic Particle Image Velocimetry (SPIV) system in a towing tank. The systematic uncertainty of the SPIV system was estimated from repeated uniform flow measurements. In the uniform flow measurement case, time interval between image frames and uniform flow speed were varied to examine the effects of particle displacement and flow around the SPIV system on the systematic standard uncertainty. The random standard uncertainty was assessed by repeating nominal wake field measurements and the estimated random standard uncertainty was compared with that of laser Doppler velocimetry. The test uncertainty assessment method was applied to nominal wake measurement tests of a very large crude oil carrier model ship. The nominal wake measurement results were compared with existing experimental database by other measurement methods, with its assessed uncertainty.

Statistical evaluation of the cleft lip nose deformity image (구순열 환자 코변형(cleft lip nose deformity) 영상의 통계적 평가)

  • Nam, Ki-Chang;Kim, Jin-Tae;Hong, Hyun-Ki;Rah, Dong-Kyun;Kim, Deok-Won
    • Proceedings of the KIEE Conference
    • /
    • 2005.05a
    • /
    • pp.45-47
    • /
    • 2005
  • Cleft lip is a congenital deformity condition with separation of the two sides of the lip and results in nose deformity. Evaluation of surgical corrections and outcome assessments in nose deformity resulting from the cleft lip depend mainly on doctor's objective judgment. Development of an objective assessment tool in evaluation of the condition and surgical outcome of cleft lip nose deformity patients will help in advancement and evaluation of surgical techniques of cleft lip. Hence, our study aimed on quantitative assessment of a cleft lip nose deformity condition by comparing following parameters gathered from a photographic image of a cleft lip patient: (1) angle difference between two nostril axis, (2) center of the nostril and distance between two centers, (3) overlapped area of two nostrils and (4) the overlapped area ratio of two nostrils. Assessment results of the nose deformity were determined by statistical analysis of evaluation results from three greatly experienced plastic surgeons. In addition, regression model was developed using correlation relationship and factor analysis of parameters from results of the image analysis.

  • PDF

Information System for Multi-scale Urban Landscape using Internet Image Map (인터넷 영상지도를 활용한 축척별 도시경관 정보시스템)

  • Um, Jung-Sup;Choi, Ja-Hyun
    • Journal of Environmental Impact Assessment
    • /
    • v.11 no.4
    • /
    • pp.289-309
    • /
    • 2002
  • Solutions of many landscape problems depend on area-wide assessment and interpretation of spatial and physical characteristics over the study area. The authors argue that the public awareness for an area-wide urban landscape appears to be very low due to limited chance to the information. Acknowledging these constraints, an operational, user-friendly information system has been developed by combining internet technology with GIS. In particular, integration among satellite data and digital maps takes advantage of each component, and enables the landscape structure to be visualized, interacted with and deployed all on the Web. The 1m resolution IKONOS data realistically identified the major type of landscape by large scale spatial precision while TM data revealed successfully the major parameters that influence an area-wide spatial structure in the study area. This system would play a crucial role in improving the public awareness for area-wide landscape information if it is operationally introduced into the Government since the highly user-friendly interface based on image maps provides a completely new means for disseminating information for area-wide landscape in a visual and interactive manner to the general public.