Image Representation - Bitmap Graphics

Image Representation - Bitmap Graphics

How Bitmap Images Work:

• Pixel: Smallest unit of an image (picture element)
• Grid: Image is a 2D grid of pixels (e.g., 1920×1080 = 2,073,600 pixels)
• Color: Each pixel stores RGB values (Red, Green, Blue)
• Storage: Store every pixel's color = large files!

Key Image Properties:

1. Resolution (Width × Height):

• 1920×1080: Full HD (2.1 megapixels)
• 3840×2160: 4K UHD (8.3 megapixels)
• 4000×3000: 12 megapixels (typical phone camera)
• Higher resolution: More detail but larger file

2. Color Depth (Bits per Pixel):

• 1-bit: Black or white (2 colors)
• 8-bit: 256 colors or grayscale
• 16-bit: 65,536 colors (old games)
• 24-bit (True Color): 16.7 million colors (8 bits per RGB channel)
• 32-bit: 24-bit + 8-bit alpha (transparency)

RGB Color Mixing (24-bit):

  Each pixel: Red (8 bits) + Green (8 bits) + Blue (8 bits) = 24 bits total
  
  Red (255, 0, 0) = pure red
  Green (0, 255, 0) = pure green  
  Blue (0, 0, 255) = pure blue
  Yellow (255, 255, 0) = red + green
  White (255, 255, 255) = all colors max
  Black (0, 0, 0) = no color
  
  Total possible colors: 256 × 256 × 256 = 16,777,216 colors