input output devices

INPUT- OUTPUT DEVICES

IMAGE AND OBJECT

Image is a representation of an object on computer.

OBJECT :

Objects are real entities defined in three dimensional (3D) coordinates.

Image is a 2D description of a 3D object.

BITMAP GRAPHICS/IMAGES

Bitmap images are pixel based. The term bitmap implies one bit per pixel

Eg: digital images

VECTOR GRAPHICS/IMAGES

Vector images are built using some mathematical equations.

If any changes are to be done then those changes are done in the equations.

OUTPUT DEVICES

Required to force the

electrons to converge into small spots

RASTER SCAN DISPLAY

RANDOM SCAN

FLAT PANEL DISPLAY:

Cathode ray tubes are replaced by flat panel display devices because this device have reduced size and weight.

A significant feature is that they are thinner than CRTs and we can hang them on walls or wear them on wrists.

TWO CATEGORIES

1. EMMISSIVE DISPLAY: they convert electrical energy to light.

2. NON-EMMISSIVE DISPLAY: they use optical effects to convert sunlight or light from the surroundings into graphics pattern

PLASMA PANEL DISPLAY.(EMMISSIVE)

LIQUID CRYSTAL DISPLAY(LCD)(NON-EMMISSIVE)