Image Processing

Introduction:

What is an Image?

What is Image Processing?

Image Characteristics

Image Processing Characteristics

Image Processing Operations


Image Coding

Image coding reduces the storage requirement for an image by removing redundant information. This may be done in two ways.

Exact Coding

The image may be reconstructed exactly. Standard coding techniques may be used.
Compression of 2:1 is typically achieved.

Fidelity Coding

Applications of Image Coding

Image Enhancement

An image may need to be processed so that it may be viewed. For example, an X-ray image may be displayed with greater contrast in some regions so that very faint features can be seen.

Original

Enhanced

Applications of Image Enhancement

Image Restoration

If an image has known faults then these may often be corrected. A blurred image may be 'deblurred' or a noisy image may have noise removed. Restoration often relies on knowledge of the process that caused the degradation.


Original Image

Noisy Image

Noise removal applied once

Noise Removal applied twice

Original Image

Sharpened Image

Image Segmentation

Sometimes similar areas in an image must be identified, for example from an aerial photograph the land and the sea may need to be segmented.

Original Image

Segmented Image

Feature detection

Often, only part of an image is of interest.

Feature detection creates an image that contains information about the presence of certain types of features. Edges are common features.

Original Image

Edges in Image


Feature Detection using the Hough Transform

Image of Road

Hough Transform of Road Image

Applications of Image Restoration, Segmentation and Feature Detection.