Image Sensing Incoming energy lands on a sensor material responsive to that type of energy and this generates a voltage Collections of sensors are arranged to capture images Imaging Sensor Line of Image Sensors Array of Image Sensors ) 2 0 0 2 ( g n s s e c o r i P e g a m I l a t i g D i , s d o o W & z e a z n o G m o r f l n e k a t s e g a m I Image Sampling And Quantisation A digital sensor can only measure a limited number of samples at a discrete set of energy levels Quantisation is the process of converting a continuous analogue signal into a digital representation of this signal ) 2 0 0 2 ( g n s s e c o r i P e g a m I l a t i g D i , s d o o W & z e a z n o G m o r f l n e k a t s e g a m I Image Sampling And Quantisation ) 2 0 0 2 ( g n s s e c o r i P e g a m I l a t i g D i , s d o o W & z e a z n o G m o r f l n e k a t s e g a m I Image Sampling And Quantisation ) 2 0 0 2 ( g n s s e c o r i P e g a m I l a t i

Spatial Resolution The spatial resolution of an image is determined by how sampling was carried out Spatial resolution simply refers to the smallest discernable detail in an image Vision specialists will often talk about pixel size Graphic designers will talk about dots per inch (DPI) ) 2 0 0 2 ( g n s s e c o r i P e g a m I l a t i g D i , s d o o W & z e a z n o G m o r f l n e k a t s e g a m I Spatial Resolution (cont) ) 2 0 0 2 ( g n s s e c o r i P e g a m I l a t i g D i , s d o o W & z e a z n o G m o r f l n e k a t s e g a m I Spatial Resolution (cont) ) 2 0 0 2 ( g n s s e c o r i P e g a m I l a t i g D i , s d o o W & z e a z n o G m o r f l n e k a t s e g a m I Spatial Resolution (cont) ) 2 0 0 2 ( g n s s e c o r i P e g a m I l a t i g D i , s d o o W & z e a z n o G m o r f l n e k a t s e g a m I Spatial Resolution (cont) ) 2 0 0 2 ( g n s s e c o r i P e g a m I l a t i g D

The big question with resolution is always how much is enough? This all depends on what is in the image and what you would like to do with it Key questions include Does the image look aesthetically pleasing? Can you see what you need to see within the image?

Resolution: How Much Is Enough? (cont) The picture on the right is fine for counting the number of cars, but not for reading the number plate ) 2 0 0 2 ( g n s s e c o r i P e g a m I l a t i g D i , s d o o W & z e a z n o G m o r f l n e k a t s e g a m I Intensity Level Resolution (cont) Low Detail Medium Detail High Detail ) 2 0 0 2 ( g n s s e c o r i P e g a m I l a t i g D i , s d o o W & z e a z n o G m o r f l n e k a t s e g a m I Intensity Level Resolution (cont) ) 2 0 0 2 ( g n s s e c o r i P e g a m I l a t i g D i , s d o o W & z e a z n o G m o r f l n e k a t s e g a m I Intensity Level Resolution (cont) ) 2 0 0 2 ( g n s s e c o r i P e g a m I l a t i g D i , s d o o W & z e a z n o G m o r f l n e k a t s e g a m I Intensity Level Resolution (cont)