Image Processing Toolbox

Filter Design

This section describes working in the frequency domain to design filters. Topics discussed include:

• Finite impulse response (FIR) filters, the class of linear filter that the toolbox supports
• The frequency transformation method, which transforms a one-dimensional FIR filter into a two-dimensional FIR filter
• The frequency sampling method, which creates a filter based on a desired frequency response
• The windowing method, which multiplies the ideal impulse response with a window function to generate the filter
• Creating the desired frequency response matrix
• Computing the frequency response of a filter

This section assumes you are familiar with working in the frequency domain. This topic is discussed in many signal processing and image processing textbooks.

Note    Most of the design methods described in this section work by creating a two-dimensional filter from a one-dimensional filter or window created using functions from the Signal Processing Toolbox. Although this toolbox is not required, you may find it difficult to design filters in the Image Processing Toolbox if you do not have the Signal Processing Toolbox as well.

Using Predefined Filter Types

FIR Filters