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Author | Danna Xue; Luis Herranz; Javier Vazquez; Yanning Zhang |
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Title | Burst Perception-Distortion Tradeoff: Analysis and Evaluation | Type | Conference Article | |||
Year | 2023 | Publication | IEEE International Conference on Acoustics, Speech and Signal Processing | Abbreviated Journal | ||
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Abstract | Burst image restoration attempts to effectively utilize the complementary cues appearing in sequential images to produce a high-quality image. Most current methods use all the available images to obtain the reconstructed image. However, using more images for burst restoration is not always the best option regarding reconstruction quality and efficiency, as the images acquired by handheld imaging devices suffer from degradation and misalignment caused by the camera noise and shake. In this paper, we extend the perception-distortion tradeoff theory by introducing multiple-frame information. We propose the area of the unattainable region as a new metric for perception-distortion tradeoff evaluation and comparison. Based on this metric, we analyse the performance of burst restoration from the perspective of the perception-distortion tradeoff under both aligned bursts and misaligned bursts situations. Our analysis reveals the importance of inter-frame alignment for burst restoration and shows that the optimal burst length for the restoration model depends both on the degree of degradation and misalignment. | |||||
Address | Rodhes Islands; Greece; June 2023 | |||||
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Area | Expedition | Conference | ICASSP | |||
Notes | CIC; MACO | Approved | no | |||
Call Number | Admin @ si @ XHV2023 | Serial | 3909 | |||
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Author | Yawei Li; Yulun Zhang; Radu Timofte; Luc Van Gool; Zhijun Tu; Kunpeng Du; Hailing Wang; Hanting Chen; Wei Li; Xiaofei Wang; Jie Hu; Yunhe Wang; Xiangyu Kong; Jinlong Wu; Dafeng Zhang; Jianxing Zhang; Shuai Liu; Furui Bai; Chaoyu Feng; Hao Wang; Yuqian Zhang; Guangqi Shao; Xiaotao Wang; Lei Lei; Rongjian Xu; Zhilu Zhang; Yunjin Chen; Dongwei Ren; Wangmeng Zuo; Qi Wu; Mingyan Han; Shen Cheng; Haipeng Li; Ting Jiang; Chengzhi Jiang; Xinpeng Li; Jinting Luo; Wenjie Lin; Lei Yu; Haoqiang Fan; Shuaicheng Liu; Aditya Arora; Syed Waqas Zamir; Javier Vazquez; Konstantinos G. Derpanis; Michael S. Brown; Hao Li; Zhihao Zhao; Jinshan Pan; Jiangxin Dong; Jinhui Tang; Bo Yang; Jingxiang Chen; Chenghua Li; Xi Zhang; Zhao Zhang; Jiahuan Ren; Zhicheng Ji; Kang Miao; Suiyi Zhao; Huan Zheng; YanYan Wei; Kangliang Liu; Xiangcheng Du; Sijie Liu; Yingbin Zheng; Xingjiao Wu; Cheng Jin; Rajeev Irny; Sriharsha Koundinya; Vighnesh Kamath; Gaurav Khandelwal; Sunder Ali Khowaja; Jiseok Yoon; Ik Hyun Lee; Shijie Chen; Chengqiang Zhao; Huabin Yang; Zhongjian Zhang; Junjia Huang; Yanru Zhang |
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Title | NTIRE 2023 challenge on image denoising: Methods and results | Type | Conference Article | |||
Year | 2023 | Publication | Proceedings of the IEEE/CVF Conference on Computer Vision and Pattern Recognition Workshops | Abbreviated Journal | ||
Volume | Issue | Pages | 1904-1920 | |||
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Abstract | This paper reviews the NTIRE 2023 challenge on image denoising (σ = 50) with a focus on the proposed solutions and results. The aim is to obtain a network design capable to produce high-quality results with the best performance measured by PSNR for image denoising. Independent additive white Gaussian noise (AWGN) is assumed and the noise level is 50. The challenge had 225 registered participants, and 16 teams made valid submissions. They gauge the state-of-the-art for image denoising. | |||||
Address | Vancouver; Canada; June 2023 | |||||
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Area | Expedition | Conference | CVPRW | |||
Notes | MACO; CIC | Approved | no | |||
Call Number | Admin @ si @ LZT2023 | Serial | 3910 | |||
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Author | Justine Giroux; Mohammad Reza Karimi Dastjerdi; Yannick Hold-Geoffroy; Javier Vazquez; Jean François Lalonde |
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Title | Towards a Perceptual Evaluation Framework for Lighting Estimation | Type | Conference Article | |||
Year | 2024 | Publication | Arxiv | Abbreviated Journal | ||
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Abstract | rogress in lighting estimation is tracked by computing existing image quality assessment (IQA) metrics on images from standard datasets. While this may appear to be a reasonable approach, we demonstrate that doing so does not correlate to human preference when the estimated lighting is used to relight a virtual scene into a real photograph. To study this, we design a controlled psychophysical experiment where human observers must choose their preference amongst rendered scenes lit using a set of lighting estimation algorithms selected from the recent literature, and use it to analyse how these algorithms perform according to human perception. Then, we demonstrate that none of the most popular IQA metrics from the literature, taken individually, correctly represent human perception. Finally, we show that by learning a combination of existing IQA metrics, we can more accurately represent human preference. This provides a new perceptual framework to help evaluate future lighting estimation algorithms. | |||||
Address | Seattle; USA; June 2024 | |||||
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Area | Expedition | Conference | CVPR | |||
Notes | MACO; CIC | Approved | no | |||
Call Number | Admin @ si @ GDH2024 | Serial | 3999 | |||
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Author | Trevor Canham; Javier Vazquez; D Long; Richard F. Murray; Michael S Brown |
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Title | Noise Prism: A Novel Multispectral Visualization Technique | Type | Journal Article | |||
Year | 2021 | Publication | 31st Color and Imaging Conference | Abbreviated Journal | ||
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Abstract | A novel technique for visualizing multispectral images is proposed. Inspired by how prisms work, our method spreads spectral information over a chromatic noise pattern. This is accomplished by populating the pattern with pixels representing each measurement band at a count proportional to its measured intensity. The method is advantageous because it allows for lightweight encoding and visualization of spectral information
while maintaining the color appearance of the stimulus. A four alternative forced choice (4AFC) experiment was conducted to validate the method’s information-carrying capacity in displaying metameric stimuli of varying colors and spectral basis functions. The scores ranged from 100% to 20% (less than chance given the 4AFC task), with many conditions falling somewhere in between at statistically significant intervals. Using this data, color and texture difference metrics can be evaluated and optimized to predict the legibility of the visualization technique. |
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Area | Expedition | Conference | CIC | |||
Notes | MACO; CIC | Approved | no | |||
Call Number | Admin @ si @ CVL2021 | Serial | 4000 | |||
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Author | Domicele Jonauskaite; Lucia Camenzind; C. Alejandro Parraga; Cecile N Diouf; Mathieu Mercapide Ducommun; Lauriane Müller; Melanie Norberg; Christine Mohr |
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Title | Colour-emotion associations in individuals with red-green colour blindness | Type | Journal Article | |||
Year | 2021 | Publication | PeerJ | Abbreviated Journal | ||
Volume | 9 | Issue | Pages | e11180 | ||
Keywords | Affect; Chromotherapy; Colour cognition; Colour vision deficiency; Cross-modal correspondences; Daltonism; Deuteranopia; Dichromatic; Emotion; Protanopia. | |||||
Abstract | Colours and emotions are associated in languages and traditions. Some of us may convey sadness by saying feeling blue or by wearing black clothes at funerals. The first example is a conceptual experience of colour and the second example is an immediate perceptual experience of colour. To investigate whether one or the other type of experience more strongly drives colour-emotion associations, we tested 64 congenitally red-green colour-blind men and 66 non-colour-blind men. All participants associated 12 colours, presented as terms or patches, with 20 emotion concepts, and rated intensities of the associated emotions. We found that colour-blind and non-colour-blind men associated similar emotions with colours, irrespective of whether colours were conveyed via terms (r = .82) or patches (r = .80). The colour-emotion associations and the emotion intensities were not modulated by participants' severity of colour blindness. Hinting at some additional, although minor, role of actual colour perception, the consistencies in associations for colour terms and patches were higher in non-colour-blind than colour-blind men. Together, these results suggest that colour-emotion associations in adults do not require immediate perceptual colour experiences, as conceptual experiences are sufficient. | |||||
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Notes | CIC; LAMP; 600.120; 600.128 | Approved | no | |||
Call Number | Admin @ si @ JCP2021 | Serial | 3564 | |||
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Author | Robert Benavente; C. Alejandro Parraga; Maria Vanrell |
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Title | La influencia del contexto en la definicion de las fronteras entre las categorias cromaticas | Type | Conference Article | |||
Year | 2010 | Publication | 9th Congreso Nacional del Color | Abbreviated Journal | ||
Volume | Issue | Pages | 92–95 | |||
Keywords | Categorización del color; Apariencia del color; Influencia del contexto; Patrones de Mondrian; Modelos paramétricos | |||||
Abstract | En este artículo presentamos los resultados de un experimento de categorización de color en el que las muestras se presentaron sobre un fondo multicolor (Mondrian) para simular los efectos del contexto. Los resultados se comparan con los de un experimento previo que, utilizando un paradigma diferente, determinó las fronteras sin tener en cuenta el contexto. El análisis de los resultados muestra que las fronteras obtenidas con el experimento en contexto presentan menos confusión que las obtenidas en el experimento sin contexto. | |||||
Address | Alicante (Spain) | |||||
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ISSN | ISBN | 978-84-9717-144-1 | Medium | |||
Area | Expedition | Conference | CNC | |||
Notes | CIC | Approved | no | |||
Call Number | CAT @ cat @ BPV2010 | Serial | 1327 | |||
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Author | Naila Murray; Sandra Skaff; Luca Marchesotti; Florent Perronnin |
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Title | Towards Automatic Concept Transfer | Type | Conference Article | |||
Year | 2011 | Publication | Proceedings of the ACM SIGGRAPH/Eurographics Symposium on Non-Photorealistic Animation and Rendering | Abbreviated Journal | ||
Volume | Issue | Pages | 167.176 | |||
Keywords | chromatic modeling, color concepts, color transfer, concept transfer | |||||
Abstract | This paper introduces a novel approach to automatic concept transfer; examples of concepts are “romantic”, “earthy”, and “luscious”. The approach modifies the color content of an input image given only a concept specified by a user in natural language, thereby requiring minimal user input. This approach is particularly useful for users who are aware of the message they wish to convey in the transferred image while being unsure of the color combination needed to achieve the corresponding transfer. The user may adjust the intensity level of the concept transfer to his/her liking with a single parameter. The proposed approach uses a convex clustering algorithm, with a novel pruning mechanism, to automatically set the complexity of models of chromatic content. It also uses the Earth-Mover's Distance to compute a mapping between the models of the input image and the target chromatic concept. Results show that our approach yields transferred images which effectively represent concepts, as confirmed by a user study. | |||||
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Publisher | ACM Press | Place of Publication | Editor | |||
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ISSN | ISBN | 978-1-4503-0907-3 | Medium | |||
Area | Expedition | Conference | NPAR | |||
Notes | CIC | Approved | no | |||
Call Number | Admin @ si @ MSM2011 | Serial | 1866 | |||
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Author | Ivet Rafegas; Maria Vanrell |
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Title | Color encoding in biologically-inspired convolutional neural networks | Type | Journal Article | |||
Year | 2018 | Publication | Vision Research | Abbreviated Journal | VR | |
Volume | 151 | Issue | Pages | 7-17 | ||
Keywords | Color coding; Computer vision; Deep learning; Convolutional neural networks | |||||
Abstract | Convolutional Neural Networks have been proposed as suitable frameworks to model biological vision. Some of these artificial networks showed representational properties that rival primate performances in object recognition. In this paper we explore how color is encoded in a trained artificial network. It is performed by estimating a color selectivity index for each neuron, which allows us to describe the neuron activity to a color input stimuli. The index allows us to classify whether they are color selective or not and if they are of a single or double color. We have determined that all five convolutional layers of the network have a large number of color selective neurons. Color opponency clearly emerges in the first layer, presenting 4 main axes (Black-White, Red-Cyan, Blue-Yellow and Magenta-Green), but this is reduced and rotated as we go deeper into the network. In layer 2 we find a denser hue sampling of color neurons and opponency is reduced almost to one new main axis, the Bluish-Orangish coinciding with the dataset bias. In layers 3, 4 and 5 color neurons are similar amongst themselves, presenting different type of neurons that detect specific colored objects (e.g., orangish faces), specific surrounds (e.g., blue sky) or specific colored or contrasted object-surround configurations (e.g. blue blob in a green surround). Overall, our work concludes that color and shape representation are successively entangled through all the layers of the studied network, revealing certain parallelisms with the reported evidences in primate brains that can provide useful insight into intermediate hierarchical spatio-chromatic representations. | |||||
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Notes | CIC; 600.051; 600.087 | Approved | no | |||
Call Number | Admin @ si @RaV2018 | Serial | 3114 | |||
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Author | C. Alejandro Parraga |
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Title | Color Vision, Computational Methods for | Type | Book Chapter | |||
Year | 2014 | Publication | Encyclopedia of Computational Neuroscience | Abbreviated Journal | ||
Volume | Issue | Pages | 1-11 | |||
Keywords | Color computational vision; Computational neuroscience of color | |||||
Abstract | The study of color vision has been aided by a whole battery of computational methods that attempt to describe the mechanisms that lead to our perception of colors in terms of the information-processing properties of the visual system. Their scope is highly interdisciplinary, linking apparently dissimilar disciplines such as mathematics, physics, computer science, neuroscience, cognitive science, and psychology. Since the sensation of color is a feature of our brains, computational approaches usually include biological features of neural systems in their descriptions, from retinal light-receptor interaction to subcortical color opponency, cortical signal decoding, and color categorization. They produce hypotheses that are usually tested by behavioral or psychophysical experiments. | |||||
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Publisher | Springer-Verlag Berlin Heidelberg | Place of Publication | Editor | Dieter Jaeger; Ranu Jung | ||
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ISSN | ISBN | 978-1-4614-7320-6 | Medium | |||
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Notes | CIC; 600.074 | Approved | no | |||
Call Number | Admin @ si @ Par2014 | Serial | 2512 | |||
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Author | Shida Beigpour; Christian Riess; Joost Van de Weijer; Elli Angelopoulou |
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Title | Multi-Illuminant Estimation with Conditional Random Fields | Type | Journal Article | |||
Year | 2014 | Publication | IEEE Transactions on Image Processing | Abbreviated Journal | TIP | |
Volume | 23 | Issue | 1 | Pages | 83-95 | |
Keywords | color constancy; CRF; multi-illuminant | |||||
Abstract | Most existing color constancy algorithms assume uniform illumination. However, in real-world scenes, this is not often the case. Thus, we propose a novel framework for estimating the colors of multiple illuminants and their spatial distribution in the scene. We formulate this problem as an energy minimization task within a conditional random field over a set of local illuminant estimates. In order to quantitatively evaluate the proposed method, we created a novel data set of two-dominant-illuminant images comprised of laboratory, indoor, and outdoor scenes. Unlike prior work, our database includes accurate pixel-wise ground truth illuminant information. The performance of our method is evaluated on multiple data sets. Experimental results show that our framework clearly outperforms single illuminant estimators as well as a recently proposed multi-illuminant estimation approach. | |||||
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ISSN | 1057-7149 | ISBN | Medium | |||
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Notes | CIC; LAMP; 600.074; 600.079 | Approved | no | |||
Call Number | Admin @ si @ BRW2014 | Serial | 2451 | |||
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Author | Fahad Shahbaz Khan; Joost Van de Weijer; Sadiq Ali; Michael Felsberg |
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Title | Evaluating the impact of color on texture recognition | Type | Conference Article | |||
Year | 2013 | Publication | 15th International Conference on Computer Analysis of Images and Patterns | Abbreviated Journal | ||
Volume | 8047 | Issue | Pages | 154-162 | ||
Keywords | Color; Texture; image representation | |||||
Abstract | State-of-the-art texture descriptors typically operate on grey scale images while ignoring color information. A common way to obtain a joint color-texture representation is to combine the two visual cues at the pixel level. However, such an approach provides sub-optimal results for texture categorisation task.
In this paper we investigate how to optimally exploit color information for texture recognition. We evaluate a variety of color descriptors, popular in image classification, for texture categorisation. In addition we analyze different fusion approaches to combine color and texture cues. Experiments are conducted on the challenging scenes and 10 class texture datasets. Our experiments clearly suggest that in all cases color names provide the best performance. Late fusion is the best strategy to combine color and texture. By selecting the best color descriptor with optimal fusion strategy provides a gain of 5% to 8% compared to texture alone on scenes and texture datasets. |
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Address | York; UK; August 2013 | |||||
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Publisher | Springer Berlin Heidelberg | Place of Publication | Editor | |||
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ISSN | 0302-9743 | ISBN | 978-3-642-40260-9 | Medium | ||
Area | Expedition | Conference | CAIP | |||
Notes | CIC; 600.048 | Approved | no | |||
Call Number | Admin @ si @ KWA2013 | Serial | 2263 | |||
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Author | Maria Vanrell; Naila Murray; Robert Benavente; C. Alejandro Parraga; Xavier Otazu; Ramon Baldrich |
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Title | Perception Based Representations for Computational Colour | Type | Conference Article | |||
Year | 2011 | Publication | 3rd International Workshop on Computational Color Imaging | Abbreviated Journal | ||
Volume | 6626 | Issue | Pages | 16-30 | ||
Keywords | colour perception, induction, naming, psychophysical data, saliency, segmentation | |||||
Abstract | The perceived colour of a stimulus is dependent on multiple factors stemming out either from the context of the stimulus or idiosyncrasies of the observer. The complexity involved in combining these multiple effects is the main reason for the gap between classical calibrated colour spaces from colour science and colour representations used in computer vision, where colour is just one more visual cue immersed in a digital image where surfaces, shadows and illuminants interact seemingly out of control. With the aim to advance a few steps towards bridging this gap we present some results on computational representations of colour for computer vision. They have been developed by introducing perceptual considerations derived from the interaction of the colour of a point with its context. We show some techniques to represent the colour of a point influenced by assimilation and contrast effects due to the image surround and we show some results on how colour saliency can be derived in real images. We outline a model for automatic assignment of colour names to image points directly trained on psychophysical data. We show how colour segments can be perceptually grouped in the image by imposing shading coherence in the colour space. | |||||
Address | Milan, Italy | |||||
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Publisher | Springer-Verlag | Place of Publication | Editor | Raimondo Schettini, Shoji Tominaga, Alain Trémeau | ||
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Series Editor | Series Title | Abbreviated Series Title | LNCS | |||
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ISSN | ISBN | 978-3-642-20403-6 | Medium | |||
Area | Expedition | Conference | CCIW | |||
Notes | CIC | Approved | no | |||
Call Number | Admin @ si @ VMB2011 | Serial | 1733 | |||
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Author | Arjan Gijsenij; Theo Gevers; Joost Van de Weijer |
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Title | Computational Color Constancy: Survey and Experiments | Type | Journal Article | |||
Year | 2011 | Publication | IEEE Transactions on Image Processing | Abbreviated Journal | TIP | |
Volume | 20 | Issue | 9 | Pages | 2475-2489 | |
Keywords | computational color constancy;computer vision application;gamut-based method;learning-based method;static method;colour vision;computer vision;image colour analysis;learning (artificial intelligence);lighting | |||||
Abstract | Computational color constancy is a fundamental prerequisite for many computer vision applications. This paper presents a survey of many recent developments and state-of-the- art methods. Several criteria are proposed that are used to assess the approaches. A taxonomy of existing algorithms is proposed and methods are separated in three groups: static methods, gamut-based methods and learning-based methods. Further, the experimental setup is discussed including an overview of publicly available data sets. Finally, various freely available methods, of which some are considered to be state-of-the-art, are evaluated on two data sets. | |||||
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ISSN | 1057-7149 | ISBN | Medium | |||
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Notes | ISE;CIC | Approved | no | |||
Call Number | Admin @ si @ GGW2011 | Serial | 1717 | |||
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Author | Joost Van de Weijer; Shida Beigpour |
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Title | The Dichromatic Reflection Model: Future Research Directions and Applications | Type | Conference Article | |||
Year | 2011 | Publication | International Conference on Computer Vision, Imaging and Computer Graphics Theory and Applications | Abbreviated Journal | ||
Volume | Issue | Pages | ||||
Keywords | dblp | |||||
Abstract | The dichromatic reflection model (DRM) predicts that color distributions form a parallelogram in color space, whose shape is defined by the body reflectance and the illuminant color. In this paper we resume the assumptions which led to the DRM and shortly recall two of its main applications domains: color image segmentation and photometric invariant feature computation. After having introduced the model we discuss several limitations of the theory, especially those which are raised once working on real-world uncalibrated images. In addition, we summerize recent extensions of the model which allow to handle more complicated light interactions. Finally, we suggest some future research directions which would further extend its applicability. | |||||
Address | Algarve, Portugal | |||||
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Publisher | SciTePress | Place of Publication | Editor | Mestetskiy, Leonid and Braz, José | ||
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ISSN | ISBN | 978-989-8425-47-8 | Medium | |||
Area | Expedition | Conference | VISIGRAPP | |||
Notes | CIC | Approved | no | |||
Call Number | Admin @ si @ WeB2011 | Serial | 1778 | |||
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Author | C. Alejandro Parraga; Jordi Roca; Dimosthenis Karatzas; Sophie Wuerger |
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Title | Limitations of visual gamma corrections in LCD displays | Type | Journal Article | |||
Year | 2014 | Publication | Displays | Abbreviated Journal | Dis | |
Volume | 35 | Issue | 5 | Pages | 227–239 | |
Keywords | Display calibration; Psychophysics; Perceptual; Visual gamma correction; Luminance matching; Observer-based calibration | |||||
Abstract | A method for estimating the non-linear gamma transfer function of liquid–crystal displays (LCDs) without the need of a photometric measurement device was described by Xiao et al. (2011) [1]. It relies on observer’s judgments of visual luminance by presenting eight half-tone patterns with luminances from 1/9 to 8/9 of the maximum value of each colour channel. These half-tone patterns were distributed over the screen both over the vertical and horizontal viewing axes. We conducted a series of photometric and psychophysical measurements (consisting in the simultaneous presentation of half-tone patterns in each trial) to evaluate whether the angular dependency of the light generated by three different LCD technologies would bias the results of these gamma transfer function estimations. Our results show that there are significant differences between the gamma transfer functions measured and produced by observers at different viewing angles. We suggest appropriate modifications to the Xiao et al. paradigm to counterbalance these artefacts which also have the advantage of shortening the amount of time spent in collecting the psychophysical measurements. | |||||
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Notes | CIC; DAG; 600.052; 600.077; 600.074 | Approved | no | |||
Call Number | Admin @ si @ PRK2014 | Serial | 2511 | |||
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Author | Naila Murray; Maria Vanrell; Xavier Otazu; C. Alejandro Parraga |
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Title | Saliency Estimation Using a Non-Parametric Low-Level Vision Model | Type | Conference Article | |||
Year | 2011 | Publication | IEEE conference on Computer Vision and Pattern Recognition | Abbreviated Journal | ||
Volume | Issue | Pages | 433-440 | |||
Keywords | Gaussian mixture model;ad hoc parameter selection;center-surround inhibition windows;center-surround mechanism;color appearance model;convolution;eye-fixation data;human vision;innate spatial pooling mechanism;inverse wavelet transform;low-level visual front-end;nonparametric low-level vision model;saliency estimation;saliency map;scale integration;scale-weighted center-surround response;scale-weighting function;visual task;Gaussian processes;biology;biology computing;colour vision;computer vision;visual perception;wavelet transforms | |||||
Abstract | Many successful models for predicting attention in a scene involve three main steps: convolution with a set of filters, a center-surround mechanism and spatial pooling to construct a saliency map. However, integrating spatial information and justifying the choice of various parameter values remain open problems. In this paper we show that an efficient model of color appearance in human vision, which contains a principled selection of parameters as well as an innate spatial pooling mechanism, can be generalized to obtain a saliency model that outperforms state-of-the-art models. Scale integration is achieved by an inverse wavelet transform over the set of scale-weighted center-surround responses. The scale-weighting function (termed ECSF) has been optimized to better replicate psychophysical data on color appearance, and the appropriate sizes of the center-surround inhibition windows have been determined by training a Gaussian Mixture Model on eye-fixation data, thus avoiding ad-hoc parameter selection. Additionally, we conclude that the extension of a color appearance model to saliency estimation adds to the evidence for a common low-level visual front-end for different visual tasks. | |||||
Address | Colorado Springs | |||||
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ISSN | 1063-6919 | ISBN | 978-1-4577-0394-2 | Medium | ||
Area | Expedition | Conference | CVPR | |||
Notes | CIC | Approved | no | |||
Call Number | Admin @ si @ MVO2011 | Serial | 1757 | |||
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Author | C. Alejandro Parraga; Robert Benavente; Maria Vanrell; Ramon Baldrich |
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Title | Psychophysical measurements to model inter-colour regions of colour-naming space | Type | Journal Article | |||
Year | 2009 | Publication | Journal of Imaging Science and Technology | Abbreviated Journal | ||
Volume | 53 | Issue | 3 | Pages | 031106 (8 pages) | |
Keywords | image processing; Analysis | |||||
Abstract | JCR Impact Factor 2009: 0.391
In this paper, we present a fuzzy-set of parametric functions which segment the CIE lab space into eleven regions which correspond to the group of common universal categories present in all evolved languages as identified by anthropologists and linguists. The set of functions is intended to model a color-name assignment task by humans and differs from other models in its emphasis on the inter-color boundary regions, which were explicitly measured by means of a psychophysics experiment. In our particular implementation, the CIE lab space was segmented into eleven color categories using a Triple Sigmoid as the fuzzy sets basis, whose parameters are included in this paper. The model’s parameters were adjusted according to the psychophysical results of a yes/no discrimination paradigm where observers had to choose (English) names for isoluminant colors belonging to regions in-between neighboring categories. These colors were presented on a calibrated CRT monitor (14-bit x 3 precision). The experimental results show that inter- color boundary regions are much less defined than expected and color samples other than those near the most representatives are needed to define the position and shape of boundaries between categories. The extended set of model parameters is given as a table. |
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Call Number | CAT @ cat @ PBV2009 | Serial | 1157 | |||
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Author | O. Fors; J. Nuñez; Xavier Otazu; A. Prades; Robert D. Cardinal |
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Title | Improving the Ability of Image Sensors to Detect Faint Stars and Moving Objects Using Image Deconvolution Techniques | Type | Journal Article | |||
Year | 2010 | Publication | Sensors | Abbreviated Journal | SENS | |
Volume | 10 | Issue | 3 | Pages | 1743–1752 | |
Keywords | image processing; image deconvolution; faint stars; space debris; wavelet transform | |||||
Abstract | Abstract: In this paper we show how the techniques of image deconvolution can increase the ability of image sensors as, for example, CCD imagers, to detect faint stars or faint orbital objects (small satellites and space debris). In the case of faint stars, we show that this benefit is equivalent to double the quantum efficiency of the used image sensor or to increase the effective telescope aperture by more than 30% without decreasing the astrometric precision or introducing artificial bias. In the case of orbital objects, the deconvolution technique can double the signal-to-noise ratio of the image, which helps to discover and control dangerous objects as space debris or lost satellites. The benefits obtained using CCD detectors can be extrapolated to any kind of image sensors. | |||||
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Notes | CIC | Approved | no | |||
Call Number | CAT @ cat @ FNO2010 | Serial | 1285 | |||
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