Bitmap Graphics

A bitmap graphic is made up of pixels​

  • A pixel is a point on the screen.​
  • A computer screen is made up of lots of tiny pixels.​
  • The more small pixels you have, the better the resolution of the screen is. (look back in your jotter to the part on monitors).​
  • We usually measure resolution in dots per inch (dpi)

A Bitmap graphic is made up of pixels and each pixel is converted to a binary Value

Advantage of bit-mapped graphics​

  •   the file area is fixed.​
    • The A4 page in the previous slide will need  1.37 Mb of memory irrespective of​ the size of the graphic on the page.​
  •  the graphic can be edited to pixel level​
    • Very useful for magazine models who have spots !​

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Disadvantage of bit-mapped graphics​

  •  cannot resize the image without losing resolution​
  •  the file size is very large​
  • Compression can be used to decrease the size of these files when they are stored.​​
  • A graphic created on the screen using 300 dpi cannot be printed at a higher resolution eg 600 dpi, even if the printer is capable of this.​