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107
NeTra: A toolbox for navigating large image databases
- Multimedia Systems
, 1999
"... . We present here an implementation of NeTra, a prototype image retrieval system that uses color, texture, shape and spatial location information in segmented image regions to search and retrieve similar regions from the database. A distinguishing aspect of this system is its incorporation of a robu ..."
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Cited by 382 (15 self)
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. We present here an implementation of NeTra, a prototype image retrieval system that uses color, texture, shape and spatial location information in segmented image regions to search and retrieve similar regions from the database. A distinguishing aspect of this system is its incorporation of a robust automated image segmentation algorithm that allows object- or region-based search. Image segmentation significantly improves the quality of image retrieval when images contain multiple complex objects. Images are segmented into homogeneous regions at the time of ingest into the database, and image attributes that represent each of these regions are computed. In addition to image segmentation, other important components of the system include an efficient color representation, and indexing of color, texture, and shape features for fast search and retrieval. This representation allows the user to compose interesting queries such as "retrieve all images that contain regions that have the colo...
Review of shape representation and description techniques
, 2004
"... More and more images have been generated in digital form around the world. There is a growing interest in finding images in large collections or from remote databases. In order to nd an image, the image has to be described or represented by certain features. Shape is an important visual feature of a ..."
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Cited by 277 (4 self)
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More and more images have been generated in digital form around the world. There is a growing interest in finding images in large collections or from remote databases. In order to nd an image, the image has to be described or represented by certain features. Shape is an important visual feature of an image. Searching for images using shape features has attracted much attention. There are many shape representation and description techniques in the literature. In this paper, we classify and review these important techniques. We examine implementation procedures for each technique and discuss its advantages and disadvantages. Some recent research results are also included and discussed in this paper. Finally, we identify some promising techniques for image retrieval according to standard principles.
WARP: accurate retrieval of shapes using phase of fourier descriptors and time warping distance
- IEEE Trans. Pattern Anal. Mach. Intell
, 2005
"... Abstract-Effective and efficient retrieval of similar shapes from large image databases is still a challenging problem in spite of the high relevance that shape information can have in describing image contents. In this paper, we propose a novel Fourier-based approach, called WARP, for matching and ..."
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Cited by 54 (1 self)
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Abstract-Effective and efficient retrieval of similar shapes from large image databases is still a challenging problem in spite of the high relevance that shape information can have in describing image contents. In this paper, we propose a novel Fourier-based approach, called WARP, for matching and retrieving similar shapes. The unique characteristics of WARP are the exploitation of the phase of Fourier coefficients and the use of the Dynamic Time Warping (DTW) distance to compare shape descriptors. While phase information provides a more accurate description of object boundaries than using only the amplitude of Fourier coefficients, the DTW distance permits us to accurately match images even in the presence of (limited) phase shiftings. In terms of classical precision/recall measures, we experimentally demonstrate that WARP can gain, say, up to 35 percent in precision at a 20 percent recall level with respect to Fourier-based techniques that use neither phase nor DTW distance.
A comparative Study of Fourier Descriptors for Shape Representation and Retrieval
- Proc. of 5th Asian Conference on Computer Vision (ACCV
, 2002
"... Shape is one of the primary low level image features in Content Based Image Retrieval (CBIR). Many shape representations and retrieval methods exist. However, most of those methods either do not well capture shape features or are difficult to do normalization (making matching difficult). Among them, ..."
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Cited by 43 (1 self)
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Shape is one of the primary low level image features in Content Based Image Retrieval (CBIR). Many shape representations and retrieval methods exist. However, most of those methods either do not well capture shape features or are difficult to do normalization (making matching difficult). Among them, methods based Fourier descriptors (FDs) achieve both good representation (perceptually meaningful) and easy normalization. Besides, FDs are easy to derive and compact in terms of representation. Design of FDs focuses on how to derive Fourier invariants from Fourier coefficients and how to obtain Fourier coefficients from shape signatures. Different Fourier invariants and shape signatures have been exploited to derive FDs. In this paper, we study different FDs and build a Java retrieval framework to compare shape retrieval performance using different FDs in terms of computation complexity, robustness, convergence speed and retrieval performance. The retrieval performance of the different FDs is compared using a standard shape database. Keywords: CBIR, Shape, Fourier descriptors, Retrieval. 1.
Image Retrieval By Shape: A Comparative Study
- In Proceedings of IEEE International Conference on Multimedia and Exposition ICME
, 1999
"... Besides traditional applications (e.g., CAD/CAM and Trademark registry), new multimedia applications such as structured video, animation, and MPEG-7 standard require the storage and management of well-defined objects. This study compared four shape-based object retrieval techniques (FD, GB, DT , and ..."
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Cited by 30 (1 self)
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Besides traditional applications (e.g., CAD/CAM and Trademark registry), new multimedia applications such as structured video, animation, and MPEG-7 standard require the storage and management of well-defined objects. This study compared four shape-based object retrieval techniques (FD, GB, DT , and TPV AS). The similarity retrieval accuracy of our method (TV PAS) was comparable to the other methods, while it had the lowest computation cost to generate the shape signatures of the objects. Moreover, it has low storage requirement, and a comparable computation cost to compute the similarity between two shape signatures. In addition, TPV AS requires no normalization of the objects, and is the only method that has direct support to RST query types. We also introduced a new shape description taxonomy. 1 Introduction Many applications in the areas of CAD/CAM and computer graphics require to store and access large databases [32, 31]. These object databases are then queried and search...
Using extended feature objects for partial similarity retrieval
- THE VLDB JOURNAL
, 1997
"... In this paper, we introduce the concept of extended feature objects for similarity retrieval. Conventional approaches for similarity search in databases map each object in the database to a point in some high-dimensional feature space and define similarity as some distance measure in this space. For ..."
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Cited by 24 (9 self)
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In this paper, we introduce the concept of extended feature objects for similarity retrieval. Conventional approaches for similarity search in databases map each object in the database to a point in some high-dimensional feature space and define similarity as some distance measure in this space. For many similarity search problems, this feature-based approach is not sufficient. When retrieving partially similar polygons, for example, the search cannot be restricted to edge sequences, since similar polygon sections may start and end anywhere on the edges of the polygons. In general, inherently continuous problems such as the partial similarity search cannot be solved by using point objects in feature space. In our solution, we therefore introduce extended feature objects consisting of an infinite set of feature points. For an efficient storage and retrieval of the extended feature objects, we determine the minimal bounding boxes of the feature objects in multidimensional space and store these boxes using a spatial access structure. In our concrete polygon problem, sets of polygon sections are mapped to 2D feature objects in high-dimensional space which are then approximated by minimal bounding boxes and stored in an R ∗-tree. The selectivity of the index is improved by using an adaptive decomposition of very large feature objects and a dynamic joining of small feature objects. For the polygon problem, translation, rotation, and scaling invariance is achieved by using the Fourier-transformed curvature of the normalized polygon sections. In contrast to vertex-based algorithms, our algorithm guarantees that no false dismissals may occur and additionally provides fast search times for realistic database sizes. We evaluate our method using real polygon data of a supplier for the car manufacturing industry.
Efficient Contour-based Shape Representation and Matching
, 2003
"... This paper present s an e#cient met hod for calculat ingt he similarit y bet ween 2D closed shape cont ours. The proposed algorit hm is invariant t ot ranslat ion, scale change and rot at ion. It can be used for dat abase ret rieval or for det ect ing regions wit h a part icular shape in video sequ ..."
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Cited by 22 (2 self)
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This paper present s an e#cient met hod for calculat ingt he similarit y bet ween 2D closed shape cont ours. The proposed algorit hm is invariant t ot ranslat ion, scale change and rot at ion. It can be used for dat abase ret rieval or for det ect ing regions wit h a part icular shape in video sequences. The proposed algorit hm is suit able for real-t ime applicat ions. Int he first st age oft he algorit hm, an ordered sequence of cont our point approximat ingt he shapes is ext6 ct d fromt he input binary images. The cont ours aret ranslat ion and scale-size normalized, and small set s oft hemost likely st art ing point s for bot h shapes areext ract ed. Int he second st age,t hest art - ing point s from bot h shapes are assigned int o pairs and rot t on alignment is performed. The dissimilarit y measure is based ont he geomet rical dist nces bet ween corresponding cont our point s. A fast sub-opt imal met hod for solvingt he correspondence problem bet ween cont our point s fromt wo shapes is proposed. The dissimilarit y measure is calculat ed for each pair of st art ing point s. The lowest dissimilarit y is t ken ast he final dissimilarit y measure bet weent wo shapes. Three di#erent experiment s are carriedout usingtn proposed approach: letR r recognit ion using a web camera, our own simulat ion of Part B oft he MPEG-7 core experiment "CE-Shape1" and det ect ion of charact ers incart oon video sequences. Result s indicat et hat t he proposed dissimilarit y measure is aligned wit h human int uit ion.
Hidden markov models with spectral features for 2d shape recognition
- IEEE Transactions on Pattern Analysis Machine Intelligence
, 2001
"... AbstractÐIn this paper, we present a technique using Markov models with spectral features for recognizing 2D shapes. We will analyze the properties of Fourier spectral features derived from closed contours of 2D shapes and use these features for 2D pattern recognition. We develop algorithms for rees ..."
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Cited by 21 (3 self)
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AbstractÐIn this paper, we present a technique using Markov models with spectral features for recognizing 2D shapes. We will analyze the properties of Fourier spectral features derived from closed contours of 2D shapes and use these features for 2D pattern recognition. We develop algorithms for reestimating parameters of hidden Markov models. To demonstrate the effectiveness of our models, we have tested our methods on two image databases: hand-tools and unconstrained handwritten numerals. We are able to achieve high recognition rates of 99.4 percent and 96.7 percent without rejection on these two sets of image data, respectively. Index TermsÐHidden Markov models, spectral features, 2D shape recognition, outer contours, handwritten numeral recognition. 1
Bimodal System for Interactive Indexing and Retrieval of Pathology Images
- In Proceedings of the 4th IEEE Workshop on Applications of Computer Vision (WACV'98
, 1998
"... The prototype of a system to assist the physicians in differential diagnosis of lymphoproliferative disorders of blood cells from digitized specimens is presented. The user selects the region of interest (ROI) in the image which is then analyzed with a fast, robust color segmenter. Queries in a data ..."
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Cited by 20 (7 self)
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The prototype of a system to assist the physicians in differential diagnosis of lymphoproliferative disorders of blood cells from digitized specimens is presented. The user selects the region of interest (ROI) in the image which is then analyzed with a fast, robust color segmenter. Queries in a database of validated cases can be formulated in terms of shape (similarity invariant Fourier descriptors), texture (multiresolution simultaneous autoregressive model), color (L u v space), and area, derived from the delineated ROI. The uncertainty of the segmentation process (obtained through a numerical method) determines the accuracy of shape description (number of Fourier harmonics). Tenfold cross-validated classification over a database of 261 color 640\Theta480 images was implemented to assess the system performance. The ground truth was obtained through immunophenotyping by flow cytometry. To provide a natural man-machine interface, most input commands are bimodal: either using t...
