Compression, Image capture & optimization

  Compression

  

Compression is the reduction in size of data in order to save space.

Graphic image file formats are usually designed to compress information wherever possible (since they have the tendency to be quite large). Graphic image compression can be either lossy (some information is permanently lost) or lossless(all information can be restored).

Photo1 - High Resolution - 504kb

 Lossy - "lossy" compression is a data encoding method that compresses data by discarding some of it. Reduces number of colours within it, reducing the file size.

 Lossless -Lossless data compression is a class of data compression algorithms that allows the exact original data to be reconstructed from the compressed data. The term lossless is in contrast to lossy data compression, which only allows an approximation of the original data to be reconstructed, in exchange for better compression rates.



Photo 2 - Compressed image - 33kb

The images of the owl, show the changes that can occur when a file has been compressed. For example: In photo 1, the file size is slightly larger, and therefore contains more information, so the picture is of higher quality, in comparisson to photo 2, which is a much smaller file size, but the picture has become pixelated and less clear, losing some of the image quality from photo 1.

Image Capture

Ways of capturing digital images:

Digital Camera
Scan / photocopy
Phone Camera / uploading
Drawing Tablet
Capture card
Tablet computer (ipad)

 

 

Optimisation

optimise - make optimal; get the most out of; use best; "optimize your resources"

Making sure that within a game, the size of the graphic is as small as it can be, whilst still maintaining the quality needed, and adhering to the 'power of two' rule.

To the power of 2 rule:
A simple set of rules, that apply to all game related images, which makes sure they conform to a series of regular dimensions. This usually means doubling up or dividing down by two. This makes sure the images are proportioned correctly so they can be loaded into a game, and processed as should be.

 

 

 

Good performance is critical to the success of many games, as computers and consoles can only store limited amounts of data the images need to be as small as possible allowing more information to be added, this means that optimised data helps the game maximize its graphical rendering speed therefore optimizing the overall game performance.