Digital Picture Processing
Computer Vision
Edge and Curve Detection for Visual Scene Analysis
IEEE Transactions on Computers
Representation of Random Waveforms by Relational Trees
IEEE Transactions on Computers
The Relevance of Non-generic Events in Scale Space Models
ECCV '02 Proceedings of the 7th European Conference on Computer Vision-Part I
Understanding and Modeling the Evolution of Critical Points under Gaussian Blurring
ECCV '02 Proceedings of the 7th European Conference on Computer Vision-Part I
Time-Recursive Velocity-Adapted Spatio-Temporal Scale-Space Filters
ECCV '02 Proceedings of the 7th European Conference on Computer Vision-Part I
Resolution Selection Using Generalized Entropies of Multiresolution Histograms
ECCV '02 Proceedings of the 7th European Conference on Computer Vision-Part I
Qualitative Spatiotemporal Analysis Using an Oriented Energy Representation
ECCV '00 Proceedings of the 6th European Conference on Computer Vision-Part II
IWVF-4 Proceedings of the 4th International Workshop on Visual Form
Evoked Potential Signal Estimation Using Gaussian Radial Basis Function Network
ICANN '01 Proceedings of the International Conference on Artificial Neural Networks
Shape Models and Object Recognition
Shape, Contour and Grouping in Computer Vision
Integrating Geometric and Photometric Information for Image Retrieval
Shape, Contour and Grouping in Computer Vision
Accurate and High Quality Triangle Models from 3D Grey Scale Images
MICCAI '02 Proceedings of the 5th International Conference on Medical Image Computing and Computer-Assisted Intervention-Part II
MICCAI '01 Proceedings of the 4th International Conference on Medical Image Computing and Computer-Assisted Intervention
Invariant Feature Extraction and Object Shape Matching Using Gabor Filtering
VISUAL '02 Proceedings of the 5th International Conference on Recent Advances in Visual Information Systems
Polygon Evolution by Vertex Deletion
SCALE-SPACE '99 Proceedings of the Second International Conference on Scale-Space Theories in Computer Vision
Morphological Scale Space and Mathematical Morphology
SCALE-SPACE '99 Proceedings of the Second International Conference on Scale-Space Theories in Computer Vision
Hierarchical Non-rigid Density Object Analysis
SCALE-SPACE '99 Proceedings of the Second International Conference on Scale-Space Theories in Computer Vision
Scale-Space from a Level Lines Tree
SCALE-SPACE '99 Proceedings of the Second International Conference on Scale-Space Theories in Computer Vision
The Hausdorff Dimension and Scale-Space Normalisation of Natural Images
SCALE-SPACE '99 Proceedings of the Second International Conference on Scale-Space Theories in Computer Vision
Calculations on Critical Points under Gaussian Blurring
SCALE-SPACE '99 Proceedings of the Second International Conference on Scale-Space Theories in Computer Vision
A Compact and Multiscale Image Model Based on Level Sets
SCALE-SPACE '99 Proceedings of the Second International Conference on Scale-Space Theories in Computer Vision
Exploring Non-linear Diffusion: The Diffusion Echo
Scale-Space '01 Proceedings of the Third International Conference on Scale-Space and Morphology in Computer Vision
Complex Diffusion Processes for Image Filtering
Scale-Space '01 Proceedings of the Third International Conference on Scale-Space and Morphology in Computer Vision
Robust Multi-scale Non-rigid Registration of 3D Ultrasound Images
Scale-Space '01 Proceedings of the Third International Conference on Scale-Space and Morphology in Computer Vision
A Multi-scale Feature Likelihood Map for Direct Evaluation of Object Hypotheses
Scale-Space '01 Proceedings of the Third International Conference on Scale-Space and Morphology in Computer Vision
Computer Vision: Past and Future
Informatics - 10 Years Back. 10 Years Ahead.
Handling Feature Ambiguity in Knowledge Discovery from Time Series
DS '02 Proceedings of the 5th International Conference on Discovery Science
How the Spatial Filters of Area V1 Can Be Used for a Nearly Ideal Edge Detection
BMCV '02 Proceedings of the Second International Workshop on Biologically Motivated Computer Vision
Learning Behavior Using Multiresolution Recurrent Neural Network
CAIP '99 Proceedings of the 8th International Conference on Computer Analysis of Images and Patterns
A Scale-Space Approach to Face Recognition from Profiles
CAIP '99 Proceedings of the 8th International Conference on Computer Analysis of Images and Patterns
A Geometric Model for Cortical Magnification
BMVC '00 Proceedings of the First IEEE International Workshop on Biologically Motivated Computer Vision
Variable-Scale Smoothing and Edge Detection Guided by Stereoscopy
CVPR '98 Proceedings of the IEEE Computer Society Conference on Computer Vision and Pattern Recognition
2D Focal Plane Steerable and Scalable Cortical Filters
MICRONEURO '99 Proceedings of the 7th International Conference on Microelectronics for Neural, Fuzzy and Bio-Inspired Systems
Estimating adaptive kernels from local image grey value changes
ICIP '95 Proceedings of the 1995 International Conference on Image Processing (Vol.2)-Volume 2 - Volume 2
Comparison of Multiscale Representations for a Linking-Based Image Segmentation Model
MMBIA '96 Proceedings of the 1996 Workshop on Mathematical Methods in Biomedical Image Analysis (MMBIA '96)
High Dynamic Range Imaging: Acquisition, Display, and Image-Based Lighting (The Morgan Kaufmann Series in Computer Graphics)
Critical Scale for Unsupervised Cluster Discovery
MLDM '07 Proceedings of the 5th international conference on Machine Learning and Data Mining in Pattern Recognition
Deriving and Mining Spatiotemporal Event Schemas in In-Situ Sensor Data
ICCSA '08 Proceeding sof the international conference on Computational Science and Its Applications, Part I
Statistically Valid Graph Representations of Scale-Space Geometry
ICISP '08 Proceedings of the 3rd international conference on Image and Signal Processing
A Mathematical Operator for Automatic and Real Time Analysis of Sequences of Vascular Images
MDA '08 Proceedings of the 3rd international conference on Advances in Mass Data Analysis of Images and Signals in Medicine, Biotechnology, Chemistry and Food Industry
A Fast Scheme for Multiscale Signal Denoising
ICIAR '08 Proceedings of the 5th international conference on Image Analysis and Recognition
Curvature Feature Based Shape Analysis
ICIC '08 Proceedings of the 4th international conference on Intelligent Computing: Advanced Intelligent Computing Theories and Applications - with Aspects of Theoretical and Methodological Issues
A Global Contour-Grouping Algorithm Based on Spectral Clustering
ISNN '08 Proceedings of the 5th international symposium on Neural Networks: Advances in Neural Networks, Part II
Evaluation of Gradient Vector Flow for Interest Point Detection
ISVC '08 Proceedings of the 4th International Symposium on Advances in Visual Computing
Validation of Watershed Regions by Scale-Space Statistics
SSVM '09 Proceedings of the Second International Conference on Scale Space and Variational Methods in Computer Vision
Highlight on a Feature Extracted at Fine Scales: The Pointwise Lipschitz Regularity
SSVM '09 Proceedings of the Second International Conference on Scale Space and Variational Methods in Computer Vision
SSVM '09 Proceedings of the Second International Conference on Scale Space and Variational Methods in Computer Vision
On the Rate of Structural Change in Scale Spaces
SSVM '09 Proceedings of the Second International Conference on Scale Space and Variational Methods in Computer Vision
Diffusion-Based Detection of Carotid Artery Lumen from Ultrasound Images
ICIAR '09 Proceedings of the 6th International Conference on Image Analysis and Recognition
An Irregular Pyramid for Multi-scale Analysis of Objects and Their Parts
GbRPR '09 Proceedings of the 7th IAPR-TC-15 International Workshop on Graph-Based Representations in Pattern Recognition
Computer Vision and Image Understanding
Robust anisotropic diffusion to produce enhanced statistical parametric map from noisy fMRI
Computer Vision and Image Understanding
Generalized scale: Theory, algorithms, and application to image inhomogeneity correction
Computer Vision and Image Understanding
Computer Vision and Image Understanding
Empirical analysis of blood plasma LIBS images using different nonlinear diffusion techniques
SIP '07 Proceedings of the Ninth IASTED International Conference on Signal and Image Processing
MICCAI '09 Proceedings of the 12th International Conference on Medical Image Computing and Computer-Assisted Intervention: Part II
Multi-scale Analysis of Discrete Contours for Unsupervised Noise Detection
IWCIA '09 Proceedings of the 13th International Workshop on Combinatorial Image Analysis
ISVC '09 Proceedings of the 5th International Symposium on Advances in Visual Computing: Part I
Multiscale Comparison of Three-Dimensional Trajectories: A Preliminary Step
RSFDGrC '09 Proceedings of the 12th International Conference on Rough Sets, Fuzzy Sets, Data Mining and Granular Computing
Multi-scale temporal segmentation and outlier detection in sensor networks
ICME'09 Proceedings of the 2009 IEEE international conference on Multimedia and Expo
Expanding selfsimilar solutions of a crystalline flow with applications to contour figure analysis
Discrete Applied Mathematics - Special issue: Advances in discrete geometry and topology (DGCI 2003)
Rough fuzzy set based scale space transforms and their use in image analysis
International Journal of Approximate Reasoning
Real-time Quadrifocal Visual Odometry
International Journal of Robotics Research
Perceptually relevant and piecewise linear matching of silhouettes
Pattern Recognition
Edge enhancement by local deconvolution
Pattern Recognition
Content-adaptive feature extraction using image variance
Pattern Recognition
SCIA'03 Proceedings of the 13th Scandinavian conference on Image analysis
On manifolds in Gaussian scale space
Scale Space'03 Proceedings of the 4th international conference on Scale space methods in computer vision
A generalized discrete scale-space formulation for 2-D and 3-D signals
Scale Space'03 Proceedings of the 4th international conference on Scale space methods in computer vision
Real-time scale selection in hybrid multi-scale representations
Scale Space'03 Proceedings of the 4th international conference on Scale space methods in computer vision
An explanation for the logarithmic connection between linear and morphological systems
Scale Space'03 Proceedings of the 4th international conference on Scale space methods in computer vision
Temporal structure tree in digital linear scale space
Scale Space'03 Proceedings of the 4th international conference on Scale space methods in computer vision
Interest point detection and scale selection in space-time
Scale Space'03 Proceedings of the 4th international conference on Scale space methods in computer vision
A Markov random field approach to multi-scale shape analysis
Scale Space'03 Proceedings of the 4th international conference on Scale space methods in computer vision
Scale Space'03 Proceedings of the 4th international conference on Scale space methods in computer vision
Detection, classification, and collaborative tracking of multiple targets using video sensors
IPSN'03 Proceedings of the 2nd international conference on Information processing in sensor networks
Full affine wavelets are scale-space with a twist
SSVM'07 Proceedings of the 1st international conference on Scale space and variational methods in computer vision
Scale-space clustering with recursive validation
SSVM'07 Proceedings of the 1st international conference on Scale space and variational methods in computer vision
Nonlinear diffusion on the 2D Euclidean motion group
SSVM'07 Proceedings of the 1st international conference on Scale space and variational methods in computer vision
SSVM'07 Proceedings of the 1st international conference on Scale space and variational methods in computer vision
Human-computer interaction system based on nose tracking
HCI'07 Proceedings of the 12th international conference on Human-computer interaction: intelligent multimodal interaction environments
IEEE Transactions on Image Processing
Study of a Robust Feature: The Pointwise Lipschitz Regularity
International Journal of Computer Vision
Correspondence regions and structured images
MICAI'07 Proceedings of the artificial intelligence 6th Mexican international conference on Advances in artificial intelligence
Edge detection based on asymptote model
ICIC'07 Proceedings of the intelligent computing 3rd international conference on Advanced intelligent computing theories and applications
The global-local transformation for invariant shape representation
ISVC'07 Proceedings of the 3rd international conference on Advances in visual computing - Volume Part II
Some experiments in audio-visual speech processing
NOLISP'07 Proceedings of the 2007 international conference on Advances in nonlinear speech processing
Scale selection for anisotropic diffusion filter by Markov random field model
Pattern Recognition
Experimental comparison of continuous and discrete tangent estimators along digital curves
IWCIA'08 Proceedings of the 12th international conference on Combinatorial image analysis
Spectral shape descriptor using spherical harmonics
Integrated Computer-Aided Engineering
DGCI'09 Proceedings of the 15th IAPR international conference on Discrete geometry for computer imagery
Piecewise approximation of contours through scale-space selection of dominant points
IEEE Transactions on Image Processing
Anisotropic diffusion for preserving boundary-edge
ICACT'10 Proceedings of the 12th international conference on Advanced communication technology
New total variation regularized L1 model for image restoration
Digital Signal Processing
Quasi-random nonlinear scale space
Pattern Recognition Letters
Anisotropic plate diffusion filtering for detection of cell membranes in 3D microscopy images
ISBI'10 Proceedings of the 2010 IEEE international conference on Biomedical imaging: from nano to Macro
On the convergence of planar curves under smoothing
IEEE Transactions on Image Processing
Extracting qualitative dynamics from numerical experiments
AAAI'87 Proceedings of the sixth National conference on Artificial intelligence - Volume 2
Extracting qualitative dynamics from numerical experiments
AAAI'87 Proceedings of the sixth National conference on Artificial intelligence - Volume 2
Optimizing continuity in multiscale imagery
ACM SIGGRAPH Asia 2010 papers
Generalized probabilistic scale space for image restoration
IEEE Transactions on Image Processing - Special section on distributed camera networks: sensing, processing, communication, and implementation
Efficient time and frequency methods for sampling filter functions
ICISP'10 Proceedings of the 4th international conference on Image and signal processing
Nonlinear multiscale analysis of motion trajectories
ICCVG'10 Proceedings of the 2010 international conference on Computer vision and graphics: Part I
Evolving object detectors with a GPU accelerated vision system
ICES'10 Proceedings of the 9th international conference on Evolvable systems: from biology to hardware
Learning PDEs for image restoration via optimal control
ECCV'10 Proceedings of the 11th European conference on Computer vision: Part I
Shaping receptive fields for affine invariance
CVPR'04 Proceedings of the 2004 IEEE computer society conference on Computer vision and pattern recognition
Solving ill-posed Image Processing problems using Data Assimilation
Numerical Algorithms
The Canny Edge Detector Revisited
International Journal of Computer Vision
Feature migration in morphological scale space
ICASSP'93 Proceedings of the 1993 IEEE international conference on Acoustics, speech, and signal processing: digital speech processing - Volume III
A model of multi-scale perceptual organization in information graphics
INFOVIS'03 Proceedings of the Ninth annual IEEE conference on Information visualization
Proceedings of the 2011 International Conference on Communication, Computing & Security
EURASIP Journal on Advances in Signal Processing
Interactive and anisotropic geometry processing using the screened Poisson equation
ACM SIGGRAPH 2011 papers
Local Laplacian filters: edge-aware image processing with a Laplacian pyramid
ACM SIGGRAPH 2011 papers
Improved spatial pyramid matching for image classification
ACCV'10 Proceedings of the 10th Asian conference on Computer vision - Volume Part IV
Journal of Mathematical Imaging and Vision
New Possibilities in Image Diffusion and Sharpening via High-Order Sobolev Gradient Flows
Journal of Mathematical Imaging and Vision
Two Enhanced Fourth Order Diffusion Models for Image Denoising
Journal of Mathematical Imaging and Vision
Automation of hessian-based tubularity measure response function in 3D biomedical images
Journal of Biomedical Imaging - Special issue on modern mathematics in biomedical imaging
Wavelet based boundary detection
ICOSSE'06 Proceedings of the 5th WSEAS international conference on System science and simulation in engineering
Underwater archaeological mosaicing
ICCOMP'06 Proceedings of the 10th WSEAS international conference on Computers
Outline font generating from images of ancient Chinese calligraphy
Transactions on edutainment V
A new approach for classification: visual simulation point of view
ISNN'05 Proceedings of the Second international conference on Advances in neural networks - Volume Part II
Automatic parameter optimization for de-noising MR data
MICCAI'05 Proceedings of the 8th international conference on Medical image computing and computer-assisted intervention - Volume Part II
From 3D faces to biometric identities
BioID'11 Proceedings of the COST 2101 European conference on Biometrics and ID management
Shape classification via image-based multiscale description
Pattern Recognition
The Global-Local transformation for noise resistant shape representation
Computer Vision and Image Understanding
Detection of risk factors using trajectory mining
Journal of Intelligent Information Systems
XDoG: advanced image stylization with eXtended Difference-of-Gaussians
Proceedings of the ACM SIGGRAPH/Eurographics Symposium on Non-Photorealistic Animation and Rendering
Interpreting 3D faces for augmented human-computer interaction
UAHCI'11 Proceedings of the 6th international conference on Universal access in human-computer interaction: users diversity - Volume Part II
ACIVS'11 Proceedings of the 13th international conference on Advanced concepts for intelligent vision systems
Anomaly detection in information streams without prior domain knowledge
IBM Journal of Research and Development
Locally adaptive image denoising by a statistical multiresolution criterion
Computational Statistics & Data Analysis
Computer Vision and Image Understanding
Intrinsic nonlinear multiscale image decomposition: A 2D empirical mode decomposition-like tool
Computer Vision and Image Understanding
Multiscale extension of the gravitational approach to edge detection
CAEPIA'11 Proceedings of the 14th international conference on Advances in artificial intelligence: spanish association for artificial intelligence
Wireless capsule endoscopy images enhancement via adaptive contrast diffusion
Journal of Visual Communication and Image Representation
Anisotropic $\alpha$-Kernels and Associated Flows
SIAM Journal on Imaging Sciences
Image Sharpening via Sobolev Gradient Flows
SIAM Journal on Imaging Sciences
Direct curvature scale space in corner detection
SSPR'06/SPR'06 Proceedings of the 2006 joint IAPR international conference on Structural, Syntactic, and Statistical Pattern Recognition
Image scale-space from the heat kernel
CIARP'05 Proceedings of the 10th Iberoamerican Congress conference on Progress in Pattern Recognition, Image Analysis and Applications
Analysis of multiresolution representations for compression and local description of images
VISUAL'05 Proceedings of the 8th international conference on Visual Information and Information Systems
Adaptive segmentation of color image for vision navigation of mobile robots
ISNN'06 Proceedings of the Third international conference on Advnaces in Neural Networks - Volume Part II
Multiscale Binarization of Gene Expression Data for Reconstructing Boolean Networks
IEEE/ACM Transactions on Computational Biology and Bioinformatics (TCBB)
B-spline scale-space of spline curves and surfaces
Computer-Aided Design
Low level moving-feature extraction via heat flow analogy
ISVC'06 Proceedings of the Second international conference on Advances in Visual Computing - Volume Part I
Computer Vision and Image Understanding
Empirical comparison of clustering methods for long time-series databases
AM'03 Proceedings of the Second international conference on Active Mining
Tree-Based tracking of temporal image
GbRPR'05 Proceedings of the 5th IAPR international conference on Graph-Based Representations in Pattern Recognition
Clustering time-series medical databases based on the improved multiscale matching
ISMIS'05 Proceedings of the 15th international conference on Foundations of Intelligent Systems
ACCV'09 Proceedings of the 9th Asian conference on Computer Vision - Volume Part III
Scale-Space hierarchy of singularities
DSSCV'05 Proceedings of the First international conference on Deep Structure, Singularities, and Computer Vision
Transitions of multi-scale singularity trees
DSSCV'05 Proceedings of the First international conference on Deep Structure, Singularities, and Computer Vision
Regularity and scale-space properties of fractional high order linear filtering
Scale-Space'05 Proceedings of the 5th international conference on Scale Space and PDE Methods in Computer Vision
Multi-scale singularity trees: soft-linked scale-space hierarchies
Scale-Space'05 Proceedings of the 5th international conference on Scale Space and PDE Methods in Computer Vision
A scale-space analysis of a contour figure using a crystalline flow
Scale-Space'05 Proceedings of the 5th international conference on Scale Space and PDE Methods in Computer Vision
Scale-Space'05 Proceedings of the 5th international conference on Scale Space and PDE Methods in Computer Vision
Combinatorial properties of scale space singular points
IWCIA'06 Proceedings of the 11th international conference on Combinatorial Image Analysis
Connecting the dots: constructing spatiotemporal episodes from events schemas
Transactions on Computational Science VI
SBP'10 Proceedings of the Third international conference on Social Computing, Behavioral Modeling, and Prediction
Robust edge detection using mumford-shah model and binary level set method
SSVM'11 Proceedings of the Third international conference on Scale Space and Variational Methods in Computer Vision
Bifurcation of segment edge curves in scale space
SSVM'11 Proceedings of the Third international conference on Scale Space and Variational Methods in Computer Vision
Theoretical foundations of gaussian convolution by extended box filtering
SSVM'11 Proceedings of the Third international conference on Scale Space and Variational Methods in Computer Vision
Intrackability: Characterizing Video Statistics and Pursuing Video Representations
International Journal of Computer Vision
Scale-space color blob and ridge detection
Pattern Recognition and Image Analysis
Add isotropic Gaussian kernels at own risk: more and more resilient modes in higher dimensions
Proceedings of the twenty-eighth annual symposium on Computational geometry
A robust texture feature extraction using the localized angular phase
Multimedia Tools and Applications
Scale-space line curvature estimation for straight line and circle detection
Pattern Recognition and Image Analysis
Growing Least Squares for the Analysis of Manifolds in Scale-Space
Computer Graphics Forum
Multiscale roughness measure for color image segmentation
Information Sciences: an International Journal
Tensor scale: An analytic approach with efficient computation and applications
Computer Vision and Image Understanding
Parametric visualization of high resolution correlated multi-spectral features using PCA
EUROVIS'07 Proceedings of the 9th Joint Eurographics / IEEE VGTC conference on Visualization
On Using Anisotropic Diffusion for Skeleton Extraction
International Journal of Computer Vision
Multi-scale and first derivative analysis for edge detection in TEM images
ICIAR'07 Proceedings of the 4th international conference on Image Analysis and Recognition
Scale selection for supervised image segmentation
Image and Vision Computing
Semantic interpretation of eye movements using designed structures of displayed contents
Proceedings of the 4th Workshop on Eye Gaze in Intelligent Human Machine Interaction
Pyramid transform and scale-space analysis in image analysis
Proceedings of the 15th international conference on Theoretical Foundations of Computer Vision: outdoor and large-scale real-world scene analysis
MDL-Based analysis of time series at multiple time-scales
ECML PKDD'12 Proceedings of the 2012 European conference on Machine Learning and Knowledge Discovery in Databases - Volume Part II
A difference engine for image reconstruction
EGGH'93 Proceedings of the Eighth Eurographics conference on Graphics Hardware
Direct visualization of deformation in volumes
EuroVis'09 Proceedings of the 11th Eurographics / IEEE - VGTC conference on Visualization
Visual coherence for large-scale line-plot visualizations
EuroVis'11 Proceedings of the 13th Eurographics / IEEE - VGTC conference on Visualization
Quantitative error measures for edge detection
Pattern Recognition
Uniqueness Results for Image Reconstruction from Features on Curves in α-Scale Spaces
Journal of Mathematical Imaging and Vision
Fuzzy based diffusion coefficient function in anisotropic diffusion for impulse noise removal
Proceedings of the Eighth Indian Conference on Computer Vision, Graphics and Image Processing
Image retrieval by content based on a visual attention model and genetic algorithms
SBIA'12 Proceedings of the 21st Brazilian conference on Advances in Artificial Intelligence
Laplacian eigenimages in discrete scale space
SSPR'12/SPR'12 Proceedings of the 2012 Joint IAPR international conference on Structural, Syntactic, and Statistical Pattern Recognition
On the choice of the parameters for anisotropic diffusion in image processing
Pattern Recognition
Image search—from thousands to billions in 20 years
ACM Transactions on Multimedia Computing, Communications, and Applications (TOMCCAP) - Special Sections on the 20th Anniversary of ACM International Conference on Multimedia, Best Papers of ACM Multimedia 2012
Information Sciences: an International Journal
IPMI'13 Proceedings of the 23rd international conference on Information Processing in Medical Imaging
Modeling semantic aspects of gaze behavior while catalog browsing
Proceedings of the 15th ACM on International conference on multimodal interaction
On the impact of anisotropic diffusion on edge detection
Pattern Recognition
Full length article: Singular integrals, scale-space and wavelet transforms
Journal of Approximation Theory
Context-aware features and robust image representations
Journal of Visual Communication and Image Representation
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The extrema in a signal and its first few derivatives provide a useful general-purpose qualitative description for many kinds of signals. A fundamental problem in computing such descriptions is scale: a derivative must be taken over some neighborhood, but there is seldom a principled basis for choosing its size. Scale-space filtering is a method that describes signals qualitatively, managing the ambiguity of scale in an organized and natural way. The signal is first expanded by convolution with gaussian masks over a continuum of sizes. This "scale-space" image is then collapsed, using its qualitative structure, into a tree providing a concise but complete qualitative description covering all scales of observation. The description is further refined by applying a stability criterion, to identify events that persist of large changes in scale.