Pixel Theory - Understanding digital graphics

If you want to learn Photoshop, you want to learn how to manipulate PIXELS

Pixels are the basis of "BITMAP" or "RASTER" graphics that are displayed on computer and TV screens.
  • Pixels are typically Square or Rectangular
  • Pixels are arranged in a grid, so they can appear "jaggy" when enlarged
  • Each pixel requires a certain amount of MEMORY to store and process it. The amount of memory assigned is measured in BITS
  • Pixels have a range of COLOUR depending on their "bit-depth"
    • Typical computers use 24 bit (16.777 million colours)
    • Old school 8-bit graphics have a range of 2^8 (256) colours
  • The smaller the Pixels, the less jaggy they appear to the eye


Identical resolution - smoother look
The jaggies can also be hidden using shades of colour to "smooth" the edges of a bitmap graphic

By "softening" jaggy corners, an image appears to be of higher quality - but it's actually the same resolution


400% Zoom View

You can also make graphics look more realistic by improving their RESOLUTION