## Computer Vision – The Integral Image

September 3, 2010 19 Comments

The Integral Image or *Summed Area Table, *was first introduced to us in 1984, but wasn’t properly introduced to the world of Computer Vision till 2001 by Viola and Jones with the Viola-Jones Object Detection Framework.

The Integral Image is used as a quick and effective way of calculating the sum of values (pixel values) in a given image – or a rectangular subset of a grid (the given image).

It can also, or is mainly, used for calculating the average intensity within a given image. If one wants to use the Integral Image, it is normally a wise idea to make sure the image is in *greyscale* first.