Week 9: Lecture (digital image processing)

What is digital image processing?

The lecture divided DIP into four common categories: analysis, manipulation, enhancement and transformation. 

Analysis
These operations provide information on the photo-metric features of an image, such as a histogram or colour count.

Manipulation
Operations such as flood fill and crop are classed as manipulating the image. 

Enhancement
To try and enhance an image operations such as heightening the contrast, enhancing the edges or anti-aliasing are used. 

Transformation
Images can be transformed using operations such as skew, rotate and scale. 

Image processing
Images take up a lot more memory storage than audio files. Compression algorithms are used to reduce the file size without losing quality or data. This allows more image files to be stored in the same amount of space. 

The optical nerves work like wires that connect the eyes to the brain.  Digital image processing allows technology in lenses to be implemented in the same way. This means that a good knowledge of optics is very important in order to print good photos.  The lenses in a camera are directed to bend the light so that it lands onto sensor arrays - which are grids of thousands of microscopic photocells. This grid creates picture elements (pixels) by sensing the light intensity of the image. If the sensor array has too low a resolution then the picture will look pixelated or blocky.