IDEC DATAVS2 Series - Manual (Page 75)

Instruction Manual SVS2 Series
70
16. TUTORIAL
16.1. ► Digital image
Digitization allows real images acquired by a camera to be treated using a processor.
This is done in two steps:
o
sampling: image is divided into a dot matrix; dots are termed picture elements (or more
commonly pixels);
o
quantization: each pixel is associated to a numeric value.
Such information may signify point brightness for gray scale images (0 = black, 255 = white), or three
values (Red-Blue-Green, RGB coding) for colour images.
As a result, the real image is converted to a mathematical format (the pixel matrix) which can be
processed by a personal computer.
sampling
quantization
real image
(gray scale)
Detail of sampling
Pixel matrix with brightness
information
The SVS2 sensor offers a maximum resolution of 640 × 480 pixel, which means that the personal
computer will treat acquired images as matrices consisting of 640×480 elements (307200 values).
Each element is identified by its location in the matrix, i.e. by specifying column and line and
considering the first element in the top left corner as the origin (in the matrix shown above, this would
be the pixel with brightness equal to 20).
X coordinate axis
Origin
pixel
(0,0)
Y coordinate
axi
s

0 1 2 3 4 …
0
1
2
3
4
5
6
…
Position pixel
(2,3)