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Subject
Session
Tahun
Versi
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T0934 / Multimedia Programming Foundation
4
2009
1/0
Learning Outcomes
In the end of this session, students must be
able to:
– Understand the concept of color
– Recognize the type of color
model/space
– Understand the image compression
and file format
– Recognize basic Java 2D API
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Course Outlines
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Color
Color Space
Digital Image
Digital Imaging in Java
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Color
• Color is a sensation,
perceived by the brain when
our eyes caught the light
reflected by an object
• Human eyes has three types of cones
which responds to three different kinds
of light’s wavelengths
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Tristimulus theory
• Therefore it’s suggested that any color can
be described using only three parameters
(tristimulus theory) which is called as three
primary colors
Three
Parameters
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Three Primary
Colors
Color Model
Color Model
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RGB
CMY(K)
HSB
CIE
– CIEXYZ
– CIELUV
– CIELAB.
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Color Model - RGB
• Basic model
• Additive primary color
• Light based
• Used in electronic display such as CRT
monitor, LCD/ plasma TV
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Color Model – CMY(K)
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Basic model
Subtractive primary color
Pigment based
K  to get better black
• Used in printing devices and film
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Color Model – HSB
Hue
• Color
Saturation
• Level of gray
Brightness
• Level of
illumination
• Also known as HLS (Hue-Lightness-Saturation) or HSV
(Hue-Saturation-Value)
• Used in computer graphic program
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Color Model - CIE
• RGB & CMY can’t
represent all visible colors
• Standard set by CIE
(Comission Internationale de l'Eclairage/
International Commission on Illumination)
• Based on how humans
perceive color
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Color Model - CIE
• CIEXYZ
– First CIE model
– XYZ is reformulated tristimulus value to cover all possible color
• CIELUV
– Revised CIEXYZ
• CIELAB.
– A different approach developed in 1942
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Gamut
• A range of color that can be produced by a
device or a color model
• Colour gamut of print media is (generally)
smaller than monitor RGB.
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Color Space
Color
Model
Gamut
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Color Model
Color Space
RGB
Adobe RGB
CIE RGB
sRGB
Color
Space
Color
This is an example to make a
panel that is colored by RGB
color
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Digital Image
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Raster Image
Color Depth
Indexed Image
Image Compression
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Raster Image
• Raster image  matrix/array of pixel
Original image
Shown
magnified
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Color Depth
True Color (24 bits)
8 bits
Colour Depth
>16 million possible colors
4 bits
256 colors
1 bit
16 colors
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2 colors (monochrome)
http://en.wikipedia.org/wiki/Color_depth
Indexed Image
• Indexed/palette-based color is limited to
certain bit amount of color
256 color
(8bit)
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16 (4bit)
4 color (2bit)
Image Size Property
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Image Size Property
This is an example to show an image, then get the width and height of the image
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Image Compression
• Reducing the amount of bits needed to
represent an image with reasonable
quality
• Lossless compression
– Run-length coding
– Entropy coding (Huffman, Arithmethic)
– LZ variations coding (LZW, LZ77, LZ78, etc)
• Lossy compression
– Transform coding
• DCT - Discrete Cosine Transform
• DFT - Discrete Fourier Transform
• DWT – Discrete Wavelet Transform
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GIF Compression
• Graphics Interchange Format (GIF87a,
GIF89a)
• Uses the modified LZW coding
• Limited to only palette-based images
• Suitable for images with few distinctive
colours (ex : graphics drawing)
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JPEG Compression
• First general purpose image compression
standard was developed by Joint
Photographic Experts Group
• Support truecolor dan grayscale image
• Suitable for natural image
8x8 blocks
DCT
Original
Image
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Quantizer
Entropy
Encoder
Compressed
Image
JPEG variations
• Lossless JPEG
– Employs a simple differential coding method without transform
coding
• JPEG2000 Standard
– New standard for image format
– Better quality of the compresssed image
– Provides superior lossless and lossy compression
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PNG Compression
• Intended to replace patented GIF dan
complex TIFF formats
• Support truecolor, grayscale, dan palettebased image
• Suitable for cartoon image
Precompression
DEFLATE
Compression
Compressed
Image
Original Image
LZ77 + Huffman
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Digital Imaging in Java
• Digital imaging was supported by three
imaging model :
1. The AWT push model
2. The immediate mode model
3. The pull model
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Buffered Image
• Raster
• ColorModel
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Compressing Image in Java2D
We use Iterator Class to make compressing ability in Java2D.
setCompressionQuality use value between 0 and 1.
Remember to use double (with f at the end of the number).
Full code is downloadable in Additional Material
References
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Basic Color Theory for the Desktop. 2000.
http://dba.med.sc.edu/price/irf/Adobe_tg/color/main.html
Colour Image Processing. 1997.
http://www.cse.iitk.ac.in/users/amit/courses/768/vision/robyn/colorvis/colour.
html
Indexed Color and Palettes. 2008. http://www.scantips.com/palettes.html
Multimedia Data. 2001.
http://www.cs.cf.ac.uk/Dave/Multimedia/node141.html
Programming in Java Advanced Imaging. 1999.
http://java.sun.com/products/java-media/jai/forDevelopers/jai1_0_1guideunc/J2D-concepts.doc.html
Color. 2009. http://en.wikipedia.org/wiki/Color
Color Model. 2009. http://en.wikipedia.org/wiki/Color_model
Digital imaging. 2009. http://en.wikipedia.org/wiki/Digital_imaging
Image Compression. 2009. http://en.wikipedia.org/wiki/Image_compression
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