An image defined in the
"real world" is considered to be a function of two real variables say
x,y.
Before going to processing an image, it is converted into a digital form.
Digitization includes sampling of image and quantization of sampled values.
After
converting the image into bit information, processing is performed.
This
processing technique may be,
" Image enhancement
" Image reconstruction
"
Image compression
Image enhancement refers to accentuation, or sharpening,
of image features such as boundaries.
Image restoration is concerned with
filtering the observed image to minimize the effect of degradations.
Image
compression is concerned with minimizing the no of bits required to represent
an image.
Text compression - CCITT GROUP3 & GROUP4
Still image compression
- JPEG
Video image compression -MPEG
Modern digital technology has made
it possible to manipulate multi-dimensional signals with systems that range from
simple digital circuits to advanced parallel computers. The goal of this manipulation
can be divided into three categories:
*
Image Processing image in -> image out
* Image Analysis image in ->
measurements out
* Image Understanding image in -> high-level description
out
Image processing is referred to processing of a 2D picture by a computer.