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Research Activities at Computer Vision and Image Understanding Group Florida State University. Xiuwen Liu Florida State Vision Group Department of Computer Science Florida State University http://fsvision.cs.fsu.edu. Outline. Motivations Some applications of computer vision techniques
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Research Activities at Computer Vision and Image Understanding GroupFlorida State University Xiuwen Liu Florida State Vision Group Department of Computer Science Florida State University http://fsvision.cs.fsu.edu
Outline • Motivations • Some applications of computer vision techniques • Computer Vision and Image Understanding Group • Some of the research projects • Contact information
Introduction • An image patch represented by hexadecimals
Introduction - continued • Fundamental problem in computer vision • Given a matrix of numbers representing an image, or a sequence of images, how to generate a perceptually meaningful description of the matrix? • An image can be a color image, gray level image, or other format such as remote sensing images • A two-dimensional matrix represents a signal image • A three-dimensional matrix represents a sequence of images • A video sequence is a 3-D matrix • A movie is also a 3-D matrix
Introduction - continued • Why do we want to work on this problem? • It is very interesting theoretically • It involves many disciplines to develop a computational model for the problem • It is the key component to understand and model intelligence • Note that 50% of the brain is devoted to vision • It has many practical applications • Internet applications • Movie-making applications • Military applications
Computer Vision Applications • No hands across America • sponsored by Delco Electronics, AssistWare Technology, and Carnegie Mellon University • Navlab 5 drove from Pittsburgh, PA to San Diego, CA, using the RALPHcomputer program. • The trip was 2849 miles of which 2797 miles were driven automatically with no hands • Which is 98.2%
Computer Vision Applications– continued DARPA Grant Challenge: http://www.darpa.mil/grandchallenge/index.htm
Computer Vision Applications– continued • Military applications • Automated target recognition
Computer Vision Applications– continued • Extracted hydrographic regions
Computer Vision Applications– continued • Medical image analysis • Characterize different types of tissues in medical images for automated medical image analysis
Computer Vision Applications– continued • Biometrics • From faces, fingerprints, iris patterns ..... • It has many applications such as security, ATM withdrawal, credit card managements .....
Computer Vision Applications– continued • Content-based image retrieval has become an active research area to meet the needs of searching images on the web in a meaningful way • Color histogram has been widely used
Computer Vision and Image Understanding Group • Faculty: Xiuwen Liu, Anuj Srivastava, Washington Mio, Eric Klassen • Goals: Develop and implement effective image understanding algorithms and systems for images and videos from multi modalities including visible, infrared, and range sensors • Approaches: Learning-based vision algorithms, statistical modeling of objects, computational modeling and analysis of textures, statistical modeling of shapes, stochastic optimization, inference algorithms on manifolds, and Bayesian inference
Research Projects • The group offers a wide range of research possibilities • Implementation projects • Development of new applications • Development of new algorithms • Theoretical and mathematical analysis of algorithms
Implementation Projects • These projects involve implementing proven ideas and algorithms on specific datasets with specific interface and programming language constraints • For example, Haitao Wu implemented a graphical user interface for a face recognition algorithm we have as his Masters project • Yu Wang implemented a web-based interface for a content-based image retrieval algorithm
Content-based Image Retrieval Image Query System by Yu Wang
Future Implementation Possibilities • Implement a Java-based system for face detection • Implement a Java-based system for learning • Implement and improve web-based systems for content-based image and video retrieval
How can we characterize all these images perceptually? Generic Image Modeling
Spectral Histogram Representation • Spectral histogram • Given a bank of filters F(a), a = 1, …, K, a spectral histogram is defined as the marginal distribution of filter responses
LoG filter Gabor filter Spectral Histogram Representation - continued • Choice of filters • Laplacian of Gaussian filters • Gabor filters • Gradient filters • Intensity filter
Average spectral histogram error A Texture Synthesis Example • A white noise image was transformed to a perceptually similar texture by matching the spectral histogram
Observed image Synthesized image Texture Synthesis Examples - continued • A random texture image
Texture Synthesis Examples - continued • An image with periodic structures Observed image Synthesized image
Texture Synthesis Examples - continued • A mud image with some animal foot prints Mud image Synthesized image
Texture Synthesis Examples - continued • A random texture image with elements Observed image Synthesized image
Object Synthesis Examples • As in texture synthesis, we start from a random image • In addition, similar object images are used as boundary conditions in that the corresponding pixel values are not updated during sampling process
Principal Component Analysis - continued Reconstructed using 50 PCs Reconstructed using 200 PCs Original Image
Difference Between Reconstruction and Sampling Reconstruction is not sufficient to show the adequacy of a representation and sampling from the set of images with same representation is more informational
Face detection based on spectral representations • Face detection is to detect all instances of faces in a given image • Each image window is represented by its spectral histogram • A support vector machine is trained on training faces • Then the trained support vector machine is used to classify each image window in an input image • More results athttp://fsvision.fsu.edu/face-detection