GDES 45 • Images


Comparing the file formats

jpg/jpeg

gif/giff

png

  • better for photographic type images(continuous tone)
  • millions of colors(16.7 million)
  • lossy compression(throws out information to reduce file size)
  • no transparency
  • no animation
  • has a newer version(jpeg 2000)
  • reduce file size by increasing compression(which reduces quality)
  • better for images with large areas of flat color like graphics, logos, etc.
  • lossless compression(although adobe now has lossy gifs)
  • 256 colors or less
  • allows animation
  • allows 1 bit transparency(each pixel is either completely transparent or opaque)
  • reduce file size by reducing the number of colors
  • 2 versions(8bit and 24 bit)
  • poorer browser support
  • PNG preserves transparency in grayscale and RGB images using alpha channels, but results in larger files than jpg (using PNG-24)
  • PNG format supports RGB, indexed-color, grayscale, and Bitmap-mode images without alpha channels