*Image processing* is in many cases concerned with taking one array of pixels as
input and producing another array of pixels as output which in some way represents
an improvement to the original array.

For example, this processing

- may remove noise,
- improve the contrast of the image,
- remove blurring caused by movement of the camera during
image acquisition,
- it may correct for geometrical distortions caused by the lens.

We will not be considering every image processing technique in this section.

Many such techniques are dealt with in Professor Batchelor's companion course.

Many books, such as Gonzalez and Woods, are devoted to this subject

Image processing methods may be broadly divided into

**Real space**- methods -- which work by directly processing the input pixel array.
**Fourier space**- methods -- which work by firstly deriving a new representation of the input data by
performing a
*Fourier transform*, which is then processed, and finally, an*inverse Fourier transform*is performed on the resulting data to give the final output image.

- Fourier Methods
- What do frequencies mean in an image?
- Fourier Theory
- Convolution
- Fourier Transforms and Convolutions
- The Fast Fourier Transform Algorithm

- What do frequencies mean in an image?
- Smoothing Noise

David Marshall 1994-1997