Internet Graphics - PowerPoint PPT Presentation

internet graphics n.
Download
Skip this Video
Loading SlideShow in 5 Seconds..
Internet Graphics PowerPoint Presentation
Download Presentation
Internet Graphics

play fullscreen
1 / 10
Internet Graphics
126 Views
Download Presentation
qiana
Download Presentation

Internet Graphics

- - - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript

  1. Internet Graphics

  2. Representing Images • Raster Image: Images consist of “dots” of color, not lines • Pixel: Picture element-tiny rectangle • Resolution: Number of pixels • SVGA: 1280 x 1024 = 1,310,720 • VGA: 640 x 480 • Your monitor can be modified

  3. Representing Images • RGB: monitor, each pixel • Intensity: 0 (dark) – 255 (bright) • Representing Color: # - # - # • 255-255-255 = white • 100-0-0 = scarlet • 16,777,216 = 16 million colors

  4. Representing Images • Light media: RGB • Opaque media: paint • Red, blue, yellow • Printers • Cyan, yellow, magenta • Must have conversion software for translating monitor to printer

  5. Storage of Images • 1 byte = 8 bits = 255 values • Images are memory hogs • Causes problems with transmission • e.g. Image: 5 million pixels = 14 Mb • Solutions • Less “accuracy” • Compression

  6. Reducing Color Depth • Reduce the number of colors • Depth: measured by bits/pixel • True color = 3 bytes = 24 bits

  7. 8-bit Color • 1 byte = 8 bits = 256 colors • Color Palette – 256 colors • Multiple palettes are available • 8-bit number represents the particular color in the palette – not the mix of RGB • Uses 1/3 storage space + 768 bytes to define the palette

  8. Other Color Depths • 1-bit - Black & White • 4-bit = 16 colors • Simple drawings, icons • Windows, but can change palette • Start; Settings; Control Panel; Display; Appearance; Scheme

  9. Color Depth Tradeoff • Color depth vs. Resolution • Due to storage requirements, must reduce one • 1280 x 1024  256 colors • 16 M colors  640 x 480 • Photos: need more than 256 colors