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Lappeenranta University of Technology (Finland). Lecture 5. Color Image Processing. Vladimir Botchko botchko@lut.fi. Color Image Processing. Fundamentals Color models Pseudocolor image processing Full color image processing Color transformations Smoothing and Sharpening
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Lappeenranta University of Technology (Finland) Lecture 5. Color Image Processing Vladimir Botchko botchko@lut.fi
Color Image Processing • Fundamentals • Color models • Pseudocolor image processing • Full color image processing • Color transformations • Smoothing and Sharpening • Color segmentation • Noise in color images • Color image compression • Multispectral image processing
Fundamentals • Colors in the visible range of wavelengths (upper left), mixtures of light (additive primaries) (upper right) and color bars used in analysis.
Color models • Relative color gamuts of a dipslay and a printer in XYZ chromaticity coordinate system (right). • Left - XYZ color space.
Color Image Processing • Fundamentals • Color models • Pseudocolor image processing • Full color image processing • Color transformations • Smoothing and Sharpening • Color segmentation • Noise in color images • Color image compression • Multispectral image processing
Color models • http://cvision.ucsd.edu/index.htm
Color models • RGB system, HSI (or HSV) system (right) (I-intensity, V value)
Color models • Three match curves. RGB system (CIE 1931)(left), XYZ system (CIE 1931)(right)
Color models • RGB space. The right image is a rotated left image (for correspondence: BL is black, W is white).
Color models • Chromaticity
Color models • Multitriangle representation (left) • Luminance, chromaticity (right)
Color models • Karhunen-Loev system
Color Image Processing • Fundamentals • Color models • Pseudocolor image processing • Full color image processing • Color transformations • Smoothing and Sharpening • Color segmentation • Noise in color images • Color image compression • Multispectral image processing
Pseudocoloring • Myocardial perfusion study. Left is a heart attack (blue region increased), right is normal.
Pseudocoloring • Right – three images: elevation relief (upper left), the color coded magnetic field (higher values are yellowish) (upper right), the composition of first two. Left – underpainting revealed through color dipslay (Prof. L. MacDonald, Derby University,GB).
Thematic classification of six-band satellite imagery using a minimum distance classifier
Color Image Processing • Fundamentals • Color models • Pseudocolor image processing • Full color image processing • Color transformations • Smoothing and Sharpening • Color segmentation • Noise in color images • Color image compression • Multispectral image processing
Painting Restoration. A Queen house , London. The part of painting was copied from another painting (upper right) and used for restoration of the lost painting part.
Color Image Processing • Fundamentals • Color models • Pseudocolor image processing • Full color image processing • Color transformations • Smoothing and Sharpening • Color segmentation • Noise in color images • Color image compression • Multispectral image processing
Color segmentation • Image segmentation based on color feature: burnt forest area, forest fire, dead forest (brown).
Color Image Processing • Fundamentals • Color models • Pseudocolor image processing • Full color image processing • Color transformations • Smoothing and Sharpening • Color segmentation • Noise in color images • Color image compression • Multispectral image processing
Color image compression. • Original color image (upper left), compressed image (upper right), error histogram in compression (the error is a delta E – the smallest color noticible difference) and error image (large error values are white).
Color Image Processing • Fundamentals • Color models • Pseudocolor image processing • Full color image processing • Color transformations • Smoothing and Sharpening • Color segmentation • Noise in color images • Color image compression • Multispectral image processing
Using a ratio image to enhance road detail(two upper is a multispectral image components) • The third image (lower) is the dividend of the first two
Color analysis. Color similarity • Brick • Ceramic tiles • Wooden pieces • Car parts
Color analysis. The Munsell Book of Color contains a set of color patches • http://www.it.lut.fi/research/color/demonstration/demonstration.html
Color analysis. Metameric spectra. Color is the same at one illumination (left patches) and different at another illumination (right patches).
Statistical Analysis of Natural ImagesUpper curve is mean, lower curve is standard deviation
http://www.techexpo.com/WWW/opto-knowledge/ for previous picture site.http://stargate.jpl.nasa.gov/lctf/ for this picture site.