Image 1 Subject:T0934 / Multimedia Programming Foundation Session:4 Tahun:2009 Versi:1/0

Bina Nusantara 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

Course Outlines Color Color Space Digital Image Digital Imaging in Java Bina Nusantara

Color Color is a sensation, perceived by the brain when our eyes caught the light reflected by an object Bina Nusantara Human eyes has three types of cones which responds to three different kinds of light’s wavelengths

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 Bina Nusantara Three Parameters Three Primary Colors Color Model

RGB CMY(K) HSB CIE –CIEXYZ –CIELUV –CIELAB. Bina Nusantara

Color Model - RGB Basic model Additive primary color Light based Bina Nusantara Used in electronic display such as CRT monitor, LCD/ plasma TV

Color Model – CMY(K) Basic model Subtractive primary color Pigment based K  to get better black Used in printing devices and film Bina Nusantara

Color Model – HSB Also known as HLS (Hue-Lightness-Saturation) or HSV (Hue-Saturation-Value) Used in computer graphic program Bina Nusantara Color Hue Level of gray Saturation Level of illumination Brightness

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 Bina Nusantara

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 Bina Nusantara

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. Bina Nusantara

Color Space Gamut Color Model Color Space Bina Nusantara Color ModelColor Space RGBAdobe RGB CIE RGB sRGB

Color Bina Nusantara This is an example to make a panel that is colored by RGB color

Digital Image Raster Image Color Depth Indexed Image Image Compression Bina Nusantara

Raster Image Raster image  matrix/array of pixel Original image Shownmagnified

Bina Nusantara Colour Depth True Color (24 bits) 8 bits 4 bits1 bit 2 colors (monochrome)16 colors 256 colors>16 million possible colors Color Depth

Bina Nusantara Indexed Image Indexed/palette-based color is limited to certain bit amount of color 256 color (8bit) 16 (4bit)4 color (2bit)

Image Size Property Bina Nusantara

Image Size Property This is an example to show an image, then get the width and height of the image Bina Nusantara

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 Bina Nusantara

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) Bina Nusantara

JPEG Compression First general purpose image compression standard was developed by Joint Photographic Experts Group Support truecolor dan grayscale image Suitable for natural image Bina Nusantara Original Image DCTQuantizer Entropy Encoder Compressed Image 8x8 blocks

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 Bina Nusantara

PNG Compression Intended to replace patented GIF dan complex TIFF formats Support truecolor, grayscale, dan palette- based image Suitable for cartoon image Bina Nusantara Original ImagePrecompression DEFLATE Compression Compressed Image LZ77 + Huffman

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 Bina Nusantara

Buffered Image Raster ColorModel Bina Nusantara

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 Basic Color Theory for the Desktop Colour Image Processing html html Indexed Color and Palettes Multimedia Data Programming in Java Advanced Imaging unc/J2D-concepts.doc.html unc/J2D-concepts.doc.html Color Color Model Digital imaging Image Compression Bina Nusantara