Tag Archives: JPG

Image compression

A big thanks to Colin for putting me on to this YouTube channel. As we saw in today’s lesson computer images (digital) can be very large. In order to save space when we save them we must compress them. We can either do this in a lossless fashion or in a lossy fashion. With lossless you can always get back to the original without any corruption this is not possible in lossy compression.

[kml_flashembed movie="http://www.youtube.com/v/Lto-ajuqW3w" width="425" height="344" allowfullscreen="true" fvars="fs=1" /]

Graphic Files

We have been going over this for a while now and I have written a helpful posting over in the Information Systems blog.

However, I did come across this today and it got me looking on wikipedia and on Google.

Let me give you a comparison

JPG – 9.33KB

PNG – 48.1 KB

GIF – 18.4 KB

I have turned the compression up on the JPG to show that it uses lossy compression.  Download the images and use an image editor like irfanview to zoom into the pictures to check their quality.