| 1. |
- Baudrier, Etienne, et al.
(författare)
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Retrieval of the ornaments from the Hand-Press Period : An overview
- 2009
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Ingår i: Proceedings of the International Conference on Document Analysis and Recognition, ICDAR. - : IEEE. - 9780769537252 ; , s. 496-500
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Konferensbidrag (refereegranskat)abstract
- This paper deals with the topic of the retrieval of document images focused on a specific application: the ornaments of the Hand-Press period. It presents an overview as a result of the work and the discussions undertaken by a workgroup on this subject. The paper starts by giving a general view about digital libraries of ornaments and associated retrieval problematics. Two main issues are underlined: content based image retrieval (CBIR) and image difference visualization. Several contributions are summarized, commented and compared. Conclusions and open problems arising from this overview are twofold: 1. contributions on CBIR miss scale-invariant methods and don't provide significative evaluation results. 2. robust registration is the open problem for visual comparison.
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| 2. |
- Diaw, Moustapha, et al.
(författare)
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Fast process for classifying structural image pairs using Weibull parameters extracted from undersampled Local Dissimilarity Maps
- 2021
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Ingår i: 2021 29th European Signal Processing Conference (EUSIPCO). - : European Signal Processing Conference, EUSIPCO. - 9789082797060 - 9781665409001 ; , s. 631-635
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Konferensbidrag (refereegranskat)abstract
- In previous works, the Local Dissimilarity Map (LDM) was proposed to compare two binary and grayscale images. This measure is based on a Hausdorff distance, which allows to quantify locally the dissimilarities between images. In this paper, we proposed the two-parameter Weibull distribution to model the LDM and the undersampled LDMs for two structural images. To classify structural image pairs, we used the two parameters of Weibull distribution for each LDM as descriptors. They are relevant to discriminate image pairs into similar and dissimilar classes. Experiments were made on the MNIST image dataset and in our own old print image dataset. The results shown our approach is more accurate than the other measures in the literature.
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| 3. |
- Diaw, Moustapha, et al.
(författare)
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Modeling a Local Dissimilarity Map With Weibull Distribution-Application to 2-Class and Multi-Class Image Classification
- 2022
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Ingår i: IEEE Access. - : IEEE. - 2169-3536. ; 10, s. 35750-35767
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Tidskriftsartikel (refereegranskat)abstract
- Due to the considerable increase of images in everyday life, many applications require a study on their similarity. The main challenge is to find a simple and efficient method to compare and classify image pairs into similar and dissimilar classes. This study presents a new method to image pairs comparison and classification based on the modeling of the Local Dissimilarity Map (LDM). The LDM is a tool for locally measuring the dissimilarity between two binary or grayscale images. It is a measure of dissimilarities based on a modified version of the Hausdorff distance, which allows quantifying locally the dissimilarities between images. This measure is completely without parameters and generic. The image pairs classification (2-class classification) method is structured as follows. First, a statistical model for the LDM is proposed. The model parameters, used as descriptors, are relevant to discriminate similar and dissimilar image pairs. Second, classifiers are applied to compute the classification scores (2-class classification problem). In addition, this approach is robust with respect to geometric transformations such as translation compared to the state-of-the-art similarity measures. Although the main objective of this paper is to apply our approach to image pairs classification, it is also performed on a classification with more than two classes (multi-class classification). Experiments on the well-known image data sets ∗NIST and on old print data set prove that the proposed method produces comparable, even better results than the state-of-the-art methods in terms of accuracy and F(1) score.
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| 4. |
- Diaw, Moustapha, et al.
(författare)
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Optical Aerial Images Change Detection Based on a Color Local Dissimilarity Map and k-Means Clustering
- 2022
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Ingår i: IEEE Geoscience and Remote Sensing Letters. - : IEEE. - 1545-598X .- 1558-0571. ; 19
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Tidskriftsartikel (refereegranskat)abstract
- Considering the unavailability of labeled data sets in remote sensing change detection, this letter presents a novel and low complexity unsupervised change detection method based on the combination of similarity and dissimilarity measures: mutual information (MI), disjoint information (DI), and local dissimilarity map (LDM). MI and DI are calculated on sliding windows with a step of 1 pixel for each pair of channels of both images. The resulting scalar values, weighted by q and m coefficients, are multiplied by the values of the center pixels of the windows weighted by p to remove the textures on images. The changes are detected using, respectively, the grayscale LDM and color LDM. A sliding window is then used on the color LDM and each pixel is characterized by a two-parameter Weibull distribution. Binarized change maps can be obtained by using a k-means clustering on the model parameters. Experiments on optical aerial image data set show that the proposed method produces comparable, even better results, to the state-of-the-art methods in terms of recall, precision, and F-measure.
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| 5. |
- Diaw, Moustapha, et al.
(författare)
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Satellite Image Change Detection Using Disjoint Information And Local Dissimilarity Map
- 2022
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Ingår i: Proceedings - International Conference on Image Processing, ICIP. - : IEEE. - 9781665496209 ; , s. 36-40
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Konferensbidrag (refereegranskat)abstract
- This paper presents a new change detection technique for images taken from the sentinel-2 satellite between 2015 and 2018 in different regions of the world. These images are widely used in recent years for change detection. This technique is based on two dissimilarity measures: the Disjoint Information and the Local Dissimilarity Map. The disjoint information quantifies the dissimilarities between textures and the Local Dissimilarity Map those between structures of images. Firstly, the disjoint information is computed across the blocks of the RGB image channels and the value is multiplied by the center value of the pixel of each block. Secondly, the Local Dissimilarity Maps over the pre-processed channels and the average of the pixel values on the Local Dissimilarity Maps are computed. Finally, an extension of the Gaussian OTSU's threshold is used to detect changes in images. Experimental results on the well-known Onera Satellite Change Detection (OSCD) dataset show the effectiveness of our proposed method compared to the state-of-the-art deep learning methods.
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| 6. |
- Morain-Nicolier, Frédéric, et al.
(författare)
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Binary pattern matching from a local dissimilarity measure
- 2010
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Ingår i: 2010 2nd International Conference on Image Processing Theory, Tools and Applications, IPTA 2010. - : IEEE. - 9781424472482 ; , s. 417-420
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Konferensbidrag (refereegranskat)abstract
- This communication deals with finding the position of a reference shape in a given image. The proposed matcher is constructed from local dissimilarity maps. These maps allow to efficiently and robustly measure the differences between two images. It is shown an example that the matcher potentially returns less false-positives than a reference method (chamfer matching). This is possible as the local dissimilarity measure is symmetric, which makes it more robust to noise.We show that the proposed matcher is a generalization of the chamfer matching. It also allows fast computation times. A good robustness to noise is confirmed from presented simulations.
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| 7. |
- Morain-Nicolier, Frédéric, et al.
(författare)
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Gray level local dissimilarity map and global dissimilarity index for quality of medical images
- 2009
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Ingår i: 7th IFAC Symposium on Modelling and Control in Biomedical Systems (including Biological Systems) MCBMS’09. - : Elsevier. - 9783902661494 ; , s. 281-286
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Konferensbidrag (refereegranskat)abstract
- In order to evaluate performance quality of coding techniques, it is needed to have a good global index and a local index allowing the localisation of the distortions. In this study, a local dissimilarity map is presented for gray-level images. Its application to the comparison of a compressed image and its reference allows an excellent visual detection of the distortions. A global dissimilarity index is computed from the local dissimilarity map. These new measures are compared to the structural similarity index (SSIM). The results of the global measure are as good as the SSIM. The results of the local measure are quite superior to the SSIM computed in a local window. We claim these good results come from the consistency of the proposed index. It is more consistent to compute a global measure from a local one, than a local measure from a global one.
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