1
Q
image types (2)
A
analog and digital
2
Q
analog image (4)
A
- 2D function f(x,y) continuous time domain
- amplitude of function f, at any pair of f(x, y) is called the intensity/colour/ gray value of the image
- seen in analog image is varying levels of intensity/brightness, is generally continuous & not divided into small pieces
- type of images we humans see, TV, photographs, even medical images recorded on film
3
Q
digital image (3)
A
- 2D function f(x,y) spatial domain
- Represented by 2D integer array or a series of 2D arrays for each colour band (eg RGB image)
- Composed of finite number of elements each having specific locations & values. elements are called pixels, pels, picture elements
4
Q
what are pixels (3)
s
r
e
A
- Smallest element of an image
- Represented by numerical value
- Each value represents brightness/colour we see in an image
5
Q
ways to convert analog signal into digital (2)
A
Sampling, Quantisation
6
Q
sampling in conversion
A
done on x-axis.
conversion of x-axis (infinite values) to number of pixels sampled
7
Q
quantisation in conversion
A
done on y-axis.
deals with digitizing the amplitude to intensity value (pixel value)
8
Q
spatial resolution referring to in image quality (2)
s
n
A
- smallest discernable detail in an image
- number of pixels used to construct image
9
Q
what is PPI and what does it it mean relating to image resolution
A
Pixels Per Inch
more PPI = higher resolution
10
Q
how many bits in 1 byte
A
8 bits
11
Q
what digit does each bit hold
A
1 or 0
12
Q
what is 0 and 1 in image
A
0 = black
1= white
