- 标题
- 摘要
- 关键词
- 实验方案
- 产品
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Autofocus measurement for imaging devices
摘要： We propose an objective measurement protocol to evaluate the autofocus performance of a digital still camera. As most pictures today are taken with smartphones, we have designed the first implementation of this protocol for devices with touchscreen trigger. The lab evaluation must match with the users’ real-world experience. Users expect to have an autofocus that is both accurate and fast, so that every picture from their smartphone is sharp and captured precisely when they press the shutter button. There is a strong need for an objective measurement to help users choose the best device for their usage and to help camera manufacturers quantify their performance and benchmark different technologies.
关键词： smartphone,autofocus speed,shooting time lag,Image quality evaluation,autofocus irregularity,acutance
更新于2025-09-09 09:28:46
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13.2: <i>Invited Paper:</i> Study on the influential factors of display image quality
摘要： There are many factors that affect the quality of the display image, such as luminance, colorfulness, contrast, resolution, naturalness, gradation and so on. However, these factors are closely related to each other. It is difficult to consider the weight of these factors for the image quality respectively. On the basis of the research published literatures, four independent parameters and gamma characteristics are summarized, and JND analysis is carried out respectively. The experiment and analysis method of the influence of each parameter on the quality weight of the display image are discussed, and the preliminary test results are summarized.
关键词： image quality,JND,factor weight
更新于2025-09-09 09:28:46
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Image Enhancement of Wireless Capsule Endoscopy Frames Using Image Fusion Technique
摘要： Volume restriction, low battery capacity and low focal length camera in Wireless Capsule Endoscopy (WCE) result in images being of lower contrast, darkness, un-even brightness and image degradations. In this paper, a Laplacian pyramid based Image fusion of Contrast Limited Adaptive Histogram Equalization (CLAHE) and Multi-Scale Retinex with Colour Restoration (MSRCR) to integrate information of both techniques have been proposed. The proposed technique combines the information from CLAHE and MSRCR, reduces uncertainties, redundancy and maximizes the information. Experimental evaluation reveals that the proposed method outperforms existing methods in terms of Peak Signal to Noise Ratio and Structural Similarity Index Measure.
关键词： Image enhancement,Image fusion,Image quality metrics,Wireless capsule endoscopy,Retinex,Laplacian pyramid
更新于2025-09-04 15:30:14
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[IEEE 2018 Tenth International Conference on Quality of Multimedia Experience (QoMEX) - Cagliari (2018.5.29-2018.6.1)] 2018 Tenth International Conference on Quality of Multimedia Experience (QoMEX) - A Hybrid Quality Metric for Non-Integer Image Interpolation
摘要： A great need of High-Resolution (HR) images has boosted the development of interpolation techniques. However, it is still a challenging task to objectively evaluate the perceptual quality of interpolated images, especially when the interpolation factor is a non-integer. To address this issue, we propose a hybrid quality metric for non-integer image interpolation that combines both reduced-reference and no-reference philosophies. To validate the proposed metric, we construct a non-integer interpolated image database and conduct a subjective user study to collect subjective opinions for each image. Experiments on the new database show that the proposed metric outperforms previous methods by a large margin.
关键词： high-resolution images,perceptual image processing,Image quality assessment,image interpolation
更新于2025-09-04 15:30:14
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[ACM Press the 2nd International Conference - Sydney, NSW, Australia (2018.10.06-2018.10.08)] Proceedings of the 2nd International Conference on Graphics and Signal Processing - ICGSP'18 - A Comparative Analysis of Clustering Algorithms for Ultrasound Image Despeckling Applications
摘要： This paper proposes a novel framework for speckle noise suppression and edge preservation using clustering algorithms in ultrasound images. The algorithms considered are K-means clustering, fuzzy C-means clustering, possibilistic C-means, fuzzy possibilistic C-means, and possibilistic fuzzy C-means clustering. This work presents an exhaustive comparative analysis of the above clustering algorithms to consider their suitability for despeckling and identifies the best clustering algorithm. Two types of dataset are considered: medical ultrasound images of the thyroid, and synthetically modelled ultrasound images. The framework consists of several distinct phases - first the edges of the image are identified using the Canny edge operator, and then a clustering algorithm applied on high frequency coefficients extracted using wavelet transform. Finally, the preserved edges are added back to speckle suppressed image. Thus, the proposed clustering method effectively accomplishes both speckle suppression and edge preservation. This paper also presents a quantitative evaluation of results to demonstrate the effectiveness of the clustering approach.
关键词： speckle noise,Image quality metrics,Wavelet transform,Ultrasound image analysis,Canny edge detector,Clustering algorithms
更新于2025-09-04 15:30:14
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Feature selection algorithm for no-reference image quality assessment using natural scene statistics
摘要： Images play an essential part in our daily lives and the performance of various imaging applications is dependent on the user’s quality of experience. No-reference image quality assessment (NR-IQA) has gained importance to assess the perceived quality, without using any prior information of the nondistorted version of the image. Different NR-IQA techniques that utilize natural scene statistics classify the distortion type based on groups of features and then these features are used for estimating the image quality score. However, every type of distortion has a different impact on certain sets of features. In this paper, a new feature selection algorithm is proposed for distortion identification based image verity and integration evaluation that selects distinct feature groups for each distortion type. The selection procedure is based on the contribution of each feature on the Spearman rank order correlation constant (SROCC) score. Only those feature groups are used in the prediction model that have majority features with SROCC score greater than mean SROCC score of all the features. The proposed feature selection algorithm for NR-IQA shows better performance in comparison to state-of-the-art NR-IQA techniques and other feature selection algorithms when evaluated on three commonly used databases.
关键词： feature selection,No-reference image quality assessment,classification,distortion identification based image verity and integration evaluation,support vector regression
更新于2025-09-04 15:30:14
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Blind quality assessment for screen content images by combining local and global features
摘要： Recently, several no-reference image quality assessment (NR-IQA) metrics have been developed for the quality evaluation of screen content images (SCIs). While, most of them are opinion-aware methods, which are limited by the subjective opinion scores of training data. Hence, in this paper, we propose a novel opinion-unaware method to predict the quality of SCIs without any prior information. Firstly, an union feature is proposed by considering the local and global visual characteristics of human visual system simultaneously. Specifically, a local structural feature is extracted from the rough and smooth regions of SCIs by leveraging a sparse representation model. As a supplement, a global feature is obtained by combining the luminance statistical feature and local binary pattern (LBP) feature of entire SCIs. Secondly, to get rid of the limitation of subjective opinion scores, a new large-scale training dataset contained 80,000 distorted SCIs is constructed, and the quality labels of those distorted SCIs are derived by an advanced full-reference IQA metric. Thirdly, a regression model between image features and image quality labels is learned from the training dataset by employing a learning-based framework. And then, the quality scores of test SCIs can be predicted by the pre-trained regression model. The experimental results on two largest SCI-oriented databases show that the proposed method is superior to the state-of-the-art NR-IQA metrics.
关键词： Local binary patterns,Image quality assessment,Sparse representation,No-reference,Screen content image
更新于2025-09-04 15:30:14
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Endoscopic image enhancement with noise suppression
摘要： Stereoscopic endoscopes have been used increasingly in minimally invasive surgery to visualise the organ surface and manipulate various surgical tools. However, insuf?cient and irregular light sources become major challenges for endoscopic surgery. Not only do these conditions hinder image processing algorithms, sometimes surgical tools are barely visible when operating within low-light regions. In addition, low-light regions have low signal-to-noise ratio and metrication artefacts due to quantisation errors. As a result, present image enhancement methods usually suffer from heavy noise ampli?cation in low-light regions. In this Letter, the authors propose an effective method for endoscopic image enhancement by identifying different illumination regions and designing the enhancement design criteria for desired image quality. Compared with existing image enhancement methods, the proposed method is able to enhance the low-light region while preventing noise ampli?cation during image enhancement process. The proposed method is tested with 200 images acquired by endoscopic surgeries. Computed results show that the proposed algorithm can outperform state-of-the-art algorithms for image enhancement, in terms of naturalness image quality evaluator and illumination index.
关键词： image quality,endoscopic image enhancement,noise suppression,minimally invasive surgery,illumination regions
更新于2025-09-04 15:30:14
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[Advances in Intelligent Systems and Computing] Image Processing and Communications Challenges 10 Volume 892 (10th International Conference, IP&C’2018 Bydgoszcz, Poland, November 2018, Proceedings) || Ten Years of Image Processing and Communications
摘要： Image processing and communications have become emerging domains for researchers and societies all over the world. Both are widely implemented and become reality in everyday matters. In this article authors present an overview of the trends and reflect on aspects discussed during the Image Processing and Communications Conferences taking place in Bydgoszcz, Poland during last 10 years. The paper aims to reflect on this great event and its scientific contents.
关键词： Cloud computing,Biometrics,Applications,Image quality,Video processing,Pattern recognition,Network,Image processing,Cyber security
更新于2025-09-04 15:30:14
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[Lecture Notes in Electrical Engineering] Recent Trends in Communication, Computing, and Electronics Volume 524 (Select Proceedings of IC3E 2018) || Image Quality Assessment: A Review to Full Reference Indexes
摘要： An image quality index plays an increasingly vital role in image processing applications for dynamic monitoring and quality adjustment, optimization and parameter setting of the imaging systems, and finally benchmarking the image processing techniques. All the above goals highly require a sustainable quantitative measure of image quality. This manuscript analytically reviews the popular reference-based metrics of image quality which have been employed for the evaluation of image enhancement techniques. The efficiency and sustainability of eleven indexes are evaluated and compared in the assessment of image enhancement after the cancellation of speckle, salt and pepper, and Gaussian noises from MRI images separately by a linear filter and three varieties of morphological filters. The results indicate more clarity and sustainability of similarity-based indexes. The direction of designing a universal similarity-based index based on information content of the image is suggested as a future research direction.
关键词： Image quality measurement,Noise cancellation,Similarity measurement,Error measurement,Image enhancement
更新于2025-09-04 15:30:14