Sunday, September 23, 2007

Getting Started

Introduction to Digital Image Processing

Digital image processing is a technology that allows people to manipulate and analyze data in the digital images. A digital image is a picture which is divided into a grid of pixels (picture elements) in which each pixel is defined by three numbers. The first two numbers give X and Y coordinates of the pixel, and the third one gives the intensity value. The X and Y coordinates of each pixel relate it to the actual location on the CCD (sensor) of the photo element. The intensity is a measure of the amount of light collected by that photo element.

Image Types

Digital images can be classified according to the number and nature of those samples:

1.Binary (bi-level) images.
2.Grayscale images.
3.Color images.
4.False-color images or Pseudo-color images.

Binary images

A binary image is a digital image that has only two possible values for each pixel either Zero (0) or One (1). The binary image is usually stored in memory as a bitmap that is a packed array of bits.

Grayscale images

Grayscale image is an image in which the value of each pixel is a single sample. This sort of images composed of shades of gray varying from black at the weakest intensity to white at the strongest.

Grayscale images intended for visual display are typically stored with 8 bits per sample, which allows 256 intensities.

Color images

A color image includes color information for each pixel. They provide three samples RGB for each pixel.

False-color images

A false-color image is a color image derived from a grayscale one by mapping each pixel value to a color according to a table or function.

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