Edges and Corners

Edges

Edges are defined by single lines:

e(x, y) = ax + by + c The edge image is defined by

The figure below shows a generated edge image:

See MATLAB code that generated this image.

Corners

Corners are defined by two intersecting lines:

represented graphically by

The edge function is given by the product of the lines, and can be reduced to a general quadratic as shown below.

If the lines are perpendicular, the corresponding vectors must have a zero dot product, as shown below

This eliminates a term proportional to x² + y².

The figure below shows a generated corner image determined by xy:

See MATLAB code that generated this image.

Examples

Example 1

pixels in the right-hand image above are interpolated

Example 2

pixels in the right-hand image above are replicated

Maintained by John Loomis, last updated 1 November 2013