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1.
Presently, man-machine interface development is a widespread research activity. A system to understand hand drawn architectural
drawings in a CAD environment is presented in this paper. To understand a document, we have to identify its building elements
and their structural properties. An attributed graph structure is chosen as a symbolic representation of the input document
and the patterns to recognize in it. An inexact subgraph isomorphism procedure using relaxation labeling techniques is performed.
In this paper we focus on how to speed up the matching. There is a building element, the walls, characterized by a hatching
pattern. Using a straight line Hough transform (SLHT)-based method, we recognize this pattern, characterized by parallel straight
lines, and remove from the input graph the edges belonging to this pattern. The isomorphism is then applied to the remainder
of the input graph. When all the building elements have been recognized, the document is redrawn, correcting the inaccurate
strokes obtained from a hand-drawn input.
Received 6 June 1996 / Accepted 4 February 1997 相似文献
2.
We describe a system which supports dynamic user interaction with multimedia information using content-based hypermedia navigation
techniques, specialising in a technique for navigation of musical content. The model combines the principles of open hypermedia, whereby hypermedia link information is maintained by a link service, with content-based retrieval techniques in which a database is queried based on a feature of the multimedia content; our approach could be described as
‘content-based retrieval of hypermedia links’. The experimental system focuses on temporal media and consists of a set of
component-based navigational hypermedia tools. We propose the use of melodic pitch contours in this context and we present
techniques for storing and querying contours, together with experimental results. Techniques for integrating the contour database
with open hypermedia systems are also discussed. 相似文献
3.
Chi-Han Chung Author Vitae Author Vitae Chin-Chun Chang Author Vitae 《Pattern recognition》2010,43(10):3219-3232
Finding an object inside a target image by querying multimedia data is desirable, but remains a challenge. The effectiveness of region-based representation for content-based image retrieval is extensively studied in the literature. One common weakness of region-based approaches is that perform detection using low level visual features within the region and the homogeneous image regions have little correspondence to the semantic objects. Thus, the retrieval results are often far from satisfactory. In addition, the performance is significantly affected by consistency in the segmented regions of the target object from the query and database images. Instead of solving these problems independently, this paper proposes region-based object retrieval using the generalized Hough transform (GHT) and adaptive image segmentation. The proposed approach has two phases. First, a learning phase identifies and stores stable parameters for segmenting each database image. In the retrieval phase, the adaptive image segmentation process is also performed to segment a query image into regions for retrieving visual objects inside database images through the GHT with a modified voting scheme to locate the target visual object under a certain affine transformation. The learned parameters make the segmentation results of query and database images more stable and consistent. Computer simulation results show that the proposed method gives good performance in terms of retrieval accuracy, robustness, and execution speed. 相似文献
4.
Analysis of textual images using the Hough transform 总被引:13,自引:1,他引:12
The analysis of images of printed pages of text is considered. Since printed text can be viewed as textured line, the use of the Hough transform for detecting straight lines is proposed as an analysis tool. Methods for handling several discretization problems that arise in mapping the rectangular image space to the (, ) accumulator array are described. Several applications of analyzing the accumulator array are proposed. They include detecting the text skew angle, determining the signature of a text line so as to accept or reject a block as containing only text, using profile analysis to segment text into lines, and determining whether a textual block is rightside-up or otherwise. 相似文献
5.
Abstract. This paper proposes a highly parallel Hough transform algorithm for real-time straight-line extraction and its hardware implementation
on a content-addressable memory (CAM). To achieve high-speed processing, incrementation for voting, which composes the Hough
transform, and calculations for coordinate updating are carried out for the every scan line, not every edge pixel, and extracting
maxima in Hough space is executed by parallel comparing. Moreover, variously weighted voting achieves more accurate line extraction
in spite of the quantization error and noise in the image space. In the implementation, the CAM acts as a PE (processing-element)
array that effectively performs highly parallel processing for the Hough transform and also as a memory for two-dimensional
Hough space, and both voting and peak extraction are directly executed by the CAM. Evaluations of CAM hardware size, processing
time and the accuracy of line extraction show that a real-time and high-resolution Hough transform for a 256256 picture can be achieved using a single CAM chip with current VLSI technology. This CAM-based Hough transform algorithm
promises to be an important step towards the realization of a real-time and compact image-understanding system.
Received: 15 August 1998 / Accepted: 15 March 2000 相似文献
6.
Comparing images using joint histograms 总被引:11,自引:0,他引:11
Color histograms are widely used for content-based image retrieval due to their efficiency and robustness. However, a color
histogram only records an image's overall color composition, so images with very different appearances can have similar color
histograms. This problem is especially critical in large image databases, where many images have similar color histograms.
In this paper, we propose an alternative to color histograms called a joint histogram, which incorporates additional information without sacrificing the robustness of color histograms. We create a joint histogram
by selecting a set of local pixel features and constructing a multidimensional histogram. Each entry in a joint histogram
contains the number of pixels in the image that are described by a particular combination of feature values. We describe a
number of different joint histograms, and evaluate their performance for image retrieval on a database with over 210,000 images.
On our benchmarks, joint histograms outperform color histograms by an order of magnitude. 相似文献
7.
We present an efficient and accurate method for retrieving images based on color similarity with a given query image or histogram.
The method matches the query against parts of the image using histogram intersection. Efficient searching for the best matching
subimage is done by pruning the set of subimages using upper bound estimates. The method is fast, has high precision and recall
and also allows queries based on the positions of one or more objects in the database image. Experimental results showing
the efficiency of the proposed search method, and high precision and recall of retrieval are presented.
Received: 20 January 1997 / Accepted: 5 January 1998 相似文献
8.
Analyzing scenery images by monotonic tree 总被引:3,自引:0,他引:3
Content-based image retrieval (CBIR) has been an active research area in the last ten years, and a variety of techniques
have been developed. However, retrieving images on the basis of low-level features has proven unsatisfactory, and new techniques
are needed to support high-level queries. Research efforts are needed to bridge the gap between high-level semantics and low-level
features. In this paper, we present a novel approach to support semantics-based image retrieval. Our approach is based on
the monotonic tree, a derivation of the contour tree for use with discrete data. The structural elements of an image are modeled
as branches (or subtrees) of the monotonic tree. These structural elements are classified and clustered on the basis of such
properties as color, spatial location, harshness and shape. Each cluster corresponds to some semantic feature. This scheme
is applied to the analysis and retrieval of scenery images. Comparisons of experimental results of this approach with conventional
techniques using low-level features demonstrate the effectiveness of our approach. 相似文献
9.
10.
D.H. Ballard 《Pattern recognition》1981,13(2):111-122
The Hough transform is a method for detecting curves by exploiting the duality between points on a curve and parameters of that curve. The initial work showed how to detect both analytic curves(1,2) and non-analytic curves,(3) but these methods were restricted to binary edge images. This work was generalized to the detection of some analytic curves in grey level images, specifically lines,(4) circles(5) and parabolas.(6) The line detection case is the best known of these and has been ingeniously exploited in several applications.(7,8,9)We show how the boundaries of an arbitrary non-analytic shape can be used to construct a mapping between image space and Hough transform space. Such a mapping can be exploited to detect instances of that particular shape in an image. Furthermore, variations in the shape such as rotations, scale changes or figure ground reversals correspond to straightforward transformations of this mapping. However, the most remarkable property is that such mappings can be composed to build mappings for complex shapes from the mappings of simpler component shapes. This makes the generalized Hough transform a kind of universal transform which can be used to find arbitrarily complex shapes. 相似文献
11.
Stephen D. Shapiro 《Pattern recognition》1980,12(5):333-337
It is shown here that the Hough transform may be used for encoding of line curves and waveforms that consist of the concatenation of curves from an underlying set of families of curves. Several properties of the transform are given in this context. 相似文献
12.
Fast template matching using bounded partial correlation 总被引:8,自引:0,他引:8
This paper describes a novel, fast template-matching technique, referred to as bounded partial correlation (BPC), based on
the normalised cross-correlation (NCC) function. The technique consists in checking at each search position a suitable elimination
condition relying on the evaluation of an upper-bound for the NCC function. The check allows for rapidly skipping the positions
that cannot provide a better degree of match with respect to the current best-matching one. The upper-bounding function incorporates
partial information from the actual cross-correlation function and can be calculated very efficiently using a recursive scheme.
We show also a simple improvement to the basic BPC formulation that provides additional computational benefits and renders
the technique more robust with respect to the parameters choice.
Received: 2 November 2000 / Accepted: 25 July 2001
Correspondence to: L. Di Stefano 相似文献
13.
In this paper, we discuss an appearance-matching approach to the difficult problem of interpreting color scenes containing
occluded objects. We have explored the use of an iterative, coarse-to-fine sum-squared-error method that uses information
from hypothesized occlusion events to perform run-time modification of scene-to-template similarity measures. These adjustments
are performed by using a binary mask to adaptively exclude regions of the template image from the squared-error computation.
At each iteration higher resolution scene data as well as information derived from the occluding interactions between multiple
object hypotheses are used to adjust these masks. We present results which demonstrate that such a technique is reasonably
robust over a large database of color test scenes containing objects at a variety of scales, and tolerates minor 3D object
rotations and global illumination variations.
Received: 21 November 1996 / Accepted: 14 October 1997 相似文献
14.
15.
M Nixon 《Pattern recognition letters》1985,3(3):191-194
The Hough transform has been formulated to detect areas of linear brightness variation within an image. The formulation leads to significant computational advantage involving a restricted parameter search space. Two applications are included to demonstrate the efficacy of this technique. 相似文献
16.
The texture of machined surfaces provides reliable information regarding the extent of tool wear. In this paper, we propose a structure-based approach to analyzing machined surfaces. The original surface images are first preprocessed by a Canny edge detector. A new connectivity-oriented fast Hough transform is then applied to the edge image to detect all the line segments. The distributions of the orientations and lengths of the line segments are used to determine tool wear. Through our experiments, we found a strong correlation between tool wear and features. The computational complexity of the fast Hough transform is also analyzed.Received: 6 November 2002, Accepted: 18 December 2003, Published online: 13 May 2004
Correspondence to: A.A. Kassim 相似文献
17.
Yi-Ping Hung Chu-Song Chen Kuan-Chung Hung Yong-Sheng Chen Chiou-Shann Fuh 《Machine Vision and Applications》1998,10(5-6):280-291
This paper presents a new multi-pass hierarchical stereo-matching approach for generation of digital terrain models (DTMs)
from two overlapping aerial images. Our method consists of multiple passes which compute stereo matches with a coarse-to-fine
and sparse-to-dense paradigm. An image pyramid is generated and used in the hierarchical stereo matching. Within each pass,
the DTM is refined by using the image pyramid from the coarse to the fine level. At the coarsest level of the first pass,
a global stereo-matching technique, the intra-/inter-scanline matching method, is used to generate a good initial DTM for
the subsequent stereo matching. Thereafter, hierarchical block matching is applied to image locations where features are detected
to refine the DTM incrementally. In the first pass, only the feature points near salient edge segments are considered in block
matching. In the second pass, all the feature points are considered, and the DTM obtained from the first pass is used as the
initial condition for local searching. For the passes after the second pass, 3D interactive manual editing can be incorporated
into the automatic DTM refinement process whenever necessary. Experimental results have shown that our method can successfully
provide accurate DTM from aerial images. The success of our approach and system has also been demonstrated with a flight simulation
software.
Received: 4 November 1996 / Accepted: 20 October 1997 相似文献
18.
The Hough transform is a well known technique for detecting parametric curves in images. We place a particular group of Hough transforms, the probabilistic Hough transforms, in the framework of importance sampling. This framework suggests a way in which probabilistic Hough transforms can be improved: by specifying a target distribution and weighting the sampled parameters accordingly to make identification of curves easier. We investigate the use of clustering techniques to simultaneously identify multiple curves in the image. We also use probabilistic arguments to develop stopping conditions for the algorithm. Results from applying our method and two popular versions of the Hough transform to both simulated and real data are shown. 相似文献
19.
20.
A technique for real-time object recognition in digital images is described. On the one hand, our approach combines robustness against occlusions, clutter, arbitrary illumination changes, and noise with invariance under rigid motion, i.e., translation and rotation. On the other hand, the computational effort is small in order to fulfill requirements of real-time applications. Our approach uses a modification of the generalized Hough transform (GHT) to improve the GHT's performance: A novel efficient limitation of the search space in combination with a hierarchical search strategy is implemented to reduce the computational effort. To meet the demands for high precision in industrial tasks, a subsequent refinement adjusts the final pose parameters. An empirical performance evaluation of the modified GHT is presented by comparing it to two standard 2D object recognition techniques. 相似文献