Getting started with Computer Vision

5 How to process and
interpret images
a. Image as an array
A digital image is an array of pixels where each pixel is a
combination of numerical values representing the colours
and intensities at a particular point on the image.
A pixel, or picture element, is the smallest visual element of an
image and typically contains three component intensities, or
channels, such as red, green and blue. Colour digital images
are created by combining the channels to reproduce the broad
range of colours seen by the human eye.
A grayscale image refers to the number of different shades, or
depth, of a particular colour. A grayscale image can be created
from any single channel or colour of the image.
The image resolution gives the number of pixels and the aspect
ratio gives the width:height pixel ratio.
The channel contains the number of samples per point, which for
grayscale images is a single sample per pixel, whereas for colour
images is three samples per pixel (red, green, blue).
Pixel
Smallest visual element
Digital Image
A multidimensional array
of numbers
Aspect Ratio
Width:Height
Resolution
Width x Height
Channel: No. of samples per point
Single plane: Grayscale / B&W images
10
9
15
32
10
65
90
32
85
23
65
54
16
70
96
99
90
43
60
85
87
85
65
32
28
56
67
70
96
92
90
43
99
85
87
65
43
56
67
96
92
43
99
87
78
67
92
99
Three Planes: Colour images
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