1 / 10

Internet Graphics

Internet Graphics. 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. Representing Images.

qiana
Télécharger la présentation

Internet Graphics

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

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

More Related