COMPUTER VISION600.461
Larry Wolff
MTW 11-12
[email protected], Office: 212NEB
Office Hours: Wed. 1-2PM
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REQUIREMENTS• This is an introductory course on Computer
Vision.• No previous knowledge of computer vision
or image analysis is required.• Prerequisite is only that you be computer
literate:
-Know how to program in C.-Have had some exposure to UNIX
type environments.
-Able to use a Web Browser.
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GRADING
• Midterm 20%
• Final 30%
• Problem Sets and Lab Projects 50%
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RESOURCES
• You will need an account on a workstation such as a SUN, DEC, or an SGI. Of course direct access to the JHU network is highly desireable.
• PCs running Linux may be OK. Windows could be problematic.
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OVERVIEW
COMPUTER IMAGING
COMPUTER VISION IMAGE PROCESSING
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TIME
VOLTAGE
X X
X
X
One Pixel
One Scanline
IMAGE
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ORGANIZATION OF A 2D IMAGE
Pixel
Binary1 bit
Grey1 byte
Color3 bytes
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BINARY IMAGE
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GREYSCALE IMAGE
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COLOR IMAGE
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RED
GREEN
BLUE
yellowmagenta
cyan
red
green
SCHEMES FOR REPRESENTING COLOR
yellow
cyan
blue
magenta
INTENSITY
RGB HSL
hue
saturation
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IMAGE FILE FORMATS
Why are there so many ?
JPEGtiff
gif
PPM
pgm
BMP
EPS
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OTHER IMAGING MODALITIES
• Medical Imaging
• Range sensing
• Thermal IR
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CATSCAN IMAGE
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RANGE IMAGE
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THERMAL IMAGE
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THE HUMAN EYE
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THE HUMAN EYE
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Raw Image Data (pixels)
Preprocessing(images, subimages)
SegmentationEdge Detection
(spectrum, edges, lines)
FeatureExtraction
Low Level
High Level
HIERARCHICAL IMAGE PYRAMID
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CONTRAST ENHANCEMENT
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THRESHOLDED SEGMENTATION
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HOMEWORK ASSIGNMENTDue Wed. Sept. 16
• Get familiar with a really useful image display tool called ‘XV’
• Works on popular ‘Command Line’ environments such as UNIX and on DECs and SGIs.
• If you don’t already have this you can ftp from ftp://ftp.cis.upenn.edu/pub/xv
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HOMEWORK ASSIGNMENTDue Wed. Sept. 16
• Access image files by logging into cs.jhu.edu via anonymous ftp
• Display the image trees.gif and enhance contrast using ‘intensity correction’.
• Try to segment trees.gif into a binary image using ‘intensity correction’.
• Display desert.gif and modify individual RGB color bands.