Raster formats

• JPG
• PNG
• GIF
• ...

GIF

• 256 colors only
• transparency
• logos, graphics with solid areas

JPG

• 16.7M colors
• no transparency
• lossy compression - fully adjustable
• photos

PNG

• 16.7M colors
• no transparency
• lossless compression
• high constrast photos, gradients, maps

Raster Data Compression

• Run-length coding (lossless)
• Quadtree coding (lossless)
• LZ77/LZW (lossless)
• JPEG (lossy)