Basics of Lambda Calculus

Tutorials

28 Mar


Lambda Calculus is a formal system for expressing computation by way of variable binding (Alpha-Conversion) and substitution (Beta-Reduction). It is a particularly useful system in Artificial Intelligence when trying to write a program that can parse sentences - such as "Every girl laughed".

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Knuth-Morris-Pratt Algorithm

Tutorials

07 Mar


Given some pattern p and some string s, how can we efficiently find out whether or not the pattern p exists within the string s as a substring of s?

In this tutorial, we discuss the workings of the Knuth-Morris-Pratt (KMP) string searching algorithm.

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The Integral Image

Tutorials

04 Mar


The integral image, or Summed Area Table, was first introduced to us in 1984. However, it was only properly introduced to the world of Computer Vision in 2001 by Viola and Jones: 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 grayscale first.

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