Representing Images in Binary

• Bitmap


  Image stored as an array of individual pixels in a 2D array of rows and columns
• Vector image


  Image representation quite different to bitmap
• Pixel


  Individual picture element, the smallest distinguishable feature of an image
• Monitor/VDU


  Divides into rows and columns of pixels
• Color


  Takes up a single pixel, not divided further
• Image/monitor size


  Expressed in pixels (width x height)
• Resolution


  Measure of detail and image quality, can be expressed as pixels per inch (PPI) or dots per inch (DPI)
• Resolution settings


  • 1920 x 1080 pixels, 24-bit color depth
• Capturing a digital image

  1. Grid placed over image

  2. Average color found for each pixel

  3. Binary value assigned to each pixel color
• Color depth/bit depth


  Number of bits used to represent each pixel color
• Increasing color depth


  Allows more shades and colors to be represented, but increases file size
• Metadata


  Data about the image data, required to properly display the image (e.g. file format, color depth, resolution)
• Metadata can also include additional information like camera details, but this increases file size