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Image Processing and virtual reality
Submitted By
P.Priyadharsini
T.Yuvapiriyaa
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Abstract
Image processing in its broadest sense is anumbrella term for representing and analyzing of data in
visual form.
The image processing is the manipulation of numericdata contained in a digital image for the purpose of
enhancing its visual appearance.
Virtual reality (VR) is a term that applies to computer-simulated environments that can simulate places in the real
world, as well as in imaginary worlds.
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Abstract
Most current virtual reality environments are primarily
visual experiences, displayed either on a computer screen
or through special stereoscopic displays.
Thus one can manipulate the images to bring out
bright or faint features, and you will "flip" images
to look for changes in them and also make the peopleto know their todaysreality in the virtual space.
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Introduction
Image Processing is a technique to enhance raw images
received from cameras/sensors placed on satellites, space
probes and aircrafts or pictures taken in normal day-to-day life
for various applications.
Virtual reality is a form of human- computer interaction in
which a real or imaginary environment is simulated and users
interact with and manipulate that world.
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Methods of image processing
There are two methods available in Image Processing.
Analog Image Processing
Digital Image Processing
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Analog Image Processing Analog Image Processing refers to the alteration of image
through electrical means. The most common example is thetelevision image.
Digital Image Processing
In this case, digital computers areused to process the image. The
image will be converted to digitalform using a scanner digitizer andthen process it.
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Image Analysis
Image analysis is concerned with making quantitativemeasurements from an image to produce a description of it.
Image analysis techniques require extraction of certain featuresthat aid in the identification of the object. The following aresome of the image analysis techniques.
Image Compression.
Image Classification.
Image Segmentation.
Image Restoration. Image Reconstruction from projections.
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Image Segmentation Image segmentation is the process that subdivides an image
into its constituent parts or objects.
The segmentation should stop when the objects of interest inan application have been isolated.
e.g., in autonomous air-to-ground target acquisition, supposeour interest lies in identifying vehicles on a road, the first
step is to segment the road from the image and then tosegment the contents of the road down to potential vehicles.
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Classification Classification is the labeling of a pixel or a group of pixels
based on its value.
Classification is one of the most often used methods ofinformation extraction. In Classification, usually multiple
features are used for a set of pixels.
Classification is of two types namely,
Supervised classification. Unsupervised classification.
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Image Restoration
Image restoration refers to removal or minimization of
degradations in an image.
This includes de-blurring of images degraded by the
limitations of a sensor or its environment, noise filtering and
correction of geometric distortion or non-linearity due to
sensors.
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Image Compression
Compression is a very essential tool for archiving image data,image data transfer on the network etc.
One of most popular compression techniques, JPEG (Joint
Photographic Experts Group) uses Discrete CosineTransformation (DCT) based compression technique.
Currently wavelet based compression techniques are used for
higher compression ratios with minimal loss of data.
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Image Reconstruction from projections.
Image reconstruction from projection is a special class ofimage restoration problems where a two- (or higher)dimensional object is reconstructed from several one-dimensional projections.
Each projection is obtained by projecting a parallel X-ray (orother penetrating radiation) beam through the object.
Planar projections are thus obtained by viewing the objectfrom many different angles.
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Types Of Image Processing
The following are the types of image processing
Image to image transformations. Image to information transformations.
Information to image transformations.
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Image to image transformations.
Enhancement (make image more useful, pleasing)
Restoration
Eg. Deblurring ,grid line removal
Geometry
(scaling ,sizing ,zooming ,morphing one object to
another).
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Image to information transformations.
Image statistics(histograms)
(Histogram is the fundamental tool for analysis and
image processing).
Image compression.
Image analysis(image segmentation ,feature extraction, pattern
recognition).
Computer-aided detection and diagnosis(CAD)
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Information To Image Transformations
Decompression of compressed image data.
Reconstruction of image slices from CT or MRI raw
data.
Computer graphics ,animations and virtual
reality(synthetic objects).
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What Is Virtual Reality
Virtual reality (VR) is a technology that allows people to enter
and interact with three-dimensional computer graphics worlds.
Another term for these worlds is virtual environments.
When a person uses a virtual world the sensory information
that is present in the real world is replaced by computer-
generated information, which may be of sufficient fidelity toallow the person effectively to believe that they are in the
virtual world.
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Hardware
The is tracker which is capable of reporting its location inspace and its orientation.
A tracker is sometimes combined with a traditional computerinput device, such as a mouse or a joystick.
An attempt to provide a truly natural input device, the data isoutfitted with sensors that can read the angle of each of thefinger joints in the hand.
Two views of the simulated world are generated, one for eacheye, and a stereoscopic display device is used to show thecorrect view to each eye.
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Serious Work or Entertainment
Virtual reality (VR) can be used to create an illusion of
reality or imagined reality and is used both for
amusement as well as serious training.
Flight trainee for training airplane pilots and astronauts
were the first form of this technology, which provided
a very realistic and very expensive simulation.
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Marketing dictionary
Virtual reality had its beginnings in computer games whereparticipants would wear special helmets and gloves and standon special platforms that simulate the sights, sounds, andmovements of characters in a real environment.
In marketing, virtual reality allows marketers to createpresentations .
For example, consumers can tour resort areas in a virtual
reality setting before they book an actual trip to the resort, orprospective computer buyers can walk through the inside of acomputer they are considering for purchase.
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Advantages
In detecting damaged facilities based on the remote sensing
images.
It gives disabled people the opportunity to join in activities not
usually available to them.
Lightweight helmets and more powerful computers will take
VR into ordinary homes.
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Applications
Image Processing
Medical Imaging.
Non-destructive Evaluation.
Forensic Studies.
Virtual Reality
Aircraft pilot training.
Medical rehabilitation.
Training for surgical procedures.
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Conclusion
Most image processing technique involve treating theimage as a two-dimensional signal and applying standardsignal-processing techniques to it .So image processingfounds application in real world.
Virtual reality has been heavily criticized for being aninefficient method for navigating non-geographicalinformation. At present, the idea of ubiquitouscomputing(Refers to the use of computers in everyday life,
including PDAs, smartphones and other mobile devices) isvery popular in user interface design, and this may be seen as areaction against VR and its problems
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References
Digital Image Processing - A Remote Sensing Perspective,John R. Jenson, 3rd Edition, Prentice Hall, 2003.
Digital Image Processing - Kenneth R. Castleman, Prentice-
Hall, 1996.
Burdea, G. and P. Coffet (2003). Virtual Reality Technology,Second Edition. Wiley-IEEE Press.
Goslin, M, and Morie, J. F., (1996). "Virtopia" Emotionalexperiences in Virtual Environments", Leonardo, vol. 29, no.2, pp. 95100.