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Media
A picture is worth 1000 words…A video is worth 1000 sentences…
Rich information from visual data Examples of images around us
Natural photographic images Artistic and engineering drawings Scientific images (satellite, medical, etc.)
Motion picture –video Movies, TV programs, news Family video Surveillance and highway camera
Why do we process images?
Enhancement and restoration remove artifacts and scratches from an old
photo/movie improve contrast and correct blurred images
Transmission and storage images from oversea via Internet, or from a
remote planet Information analysis and automated
recognition providing “human vision” to machines
Security and rights protection encryption and watermarking
Why Digital? “Exactness”
Perfect reproduction without degradation Perfect duplication of processing result
Convenient & powerful computer-aided processing Can perform rather sophisticated processing through hardwa
re or software Even kindergartners can do it!
Easy storage and transmission 1 CD can store hundreds of family photos! Paperless transmission of high quality photos through netwo
rk within seconds
Human Vision System Image is to be seen. Perceptual Based Image Processing
Focus on perceptually significant information
Discard perceptually insignificant information
Issues: Biological Psychophysical
Color Color is the perceptual result of
light having wavelength 400 nm to 700 nm that is incident upon the retina.
“Power distribution exists in the physical world, but color exists only in the eye and the brain.”
Does “red” mean the same to different people?
Color Spectrum
Grassman's First Law of Additive Color Mixture Any color can be matched by a linear
combination of three other colors (primaries, eg RGB), provided that none of those three can be matched by a combination of the other two. C= Rc(R ) + Gc(G) + Bc(B)
Color Spaces RGB CMY CIE XYZ sl
Different Image Types
Binary images (0 or 1) Gray images (0~255) Color images
indexed color images full color images (24 bits per pixel, 8-
red, 8-green, 8-blue) )
A Binary Image
Gray Images
8 bits per pixel
Full Color Images
24 bits per pixel, and the three channels R G B are three gray images respectively
Color Components
Image Programming class CImage {
unsigned int width; unsigned int height; unsigned char *data;
};
Not difficult…
Related Fields
Imaging Medical, remote sensing, weather
Computer vision Computer graphics Machine learning Video processing
Related Math
Fourier analysis Wavelet Probability and statistics PDE Linear/nonlinear optimization Machine learning …
References Journals
IEEE Transaction on Pattern Analysis and Machine Intelligence (PAMI)
IEEE Transaction on Image Processing IEEE Transaction on Signal Processing IEEE Transaction on Circuits and System for Video
Technology International Journal on Computer Vision (IJCV) Pattern Recognition
Conferences Graphics Conferences (Siggraph…) Vision conferences: ICCV, ECCV, ACCV, CVPR
Course Information
Seminar Report papers by yourselves
Grading Seminar reports and final report
Course homepage and FTP
Objectives
Learn something interesting Do something interesting Find some interesting problems
Improve your abilities and experiences!
Requirements Reporter
Over-prepared: read a series of important papers, PPT (texts and images)
Professional: PPT, explaining, interaction… List all references on the last slide His own idea or own work
Audience Challenging the reporter Ask questions Learn something new
Active and creative!
Q&A
