Image Processing Reference
In-Depth Information
Fig. 2.22
Three different types of image. (
a
) X-ray image. Note the ring on the finger. (
b
)Ther-
mographic image. The more reddish the higher the temperature. (
c
) 3D image. The more blueish
the closer to the camera
2.6
Exercises
Exercise 1:
Explain the following concepts: electromagnetic spectrum, focal
length, exposure time, backlighting, saturation, focus, depth-of-fields, motion blur,
spatial quantization, ROI.
Exercise 2:
Explain the pros and cons of backlighting.
Exercise 3:
Describe the image acquisition process. That is, from light to a digital
image in a computer.
Exercise 4:
What is the purpose of the lens?
Exercise 5:
What is the focal length and how does it relate to zoom?
Exercise 6:
How many different 512
×
512 gray-scale (8-bit) images can be con-
structed?
Exercise 7:
Which pixel value is represented by the following bit sequence:
00101010?
Exercise 8:
What is the bit sequence of the pixel value: 150?
Exercise 9:
In a 100
100 gray-scale image each pixel is represented by 256 gray
levels. How much memory (bytes) is required to store this image?
Exercise 10:
In a 100
×
100 gray-scale image each pixel is represented by 4 gray
levels. How much memory (bytes) is required to store this image?
Exercise 11:
You want to photograph an object, which is 1 m tall and 10 m away
from the camera. The height of the object in the image should be 1 mm. It is
assumed that the object is in focus at the focal point. What should the focal length
be?
Exercise 12a:
Mick is 2 m tall and standing 5 m away from a camera. The focal
length of the camera is 5 mm. A focused image of Mick is formed on the sensor.
At which distance from the lens is the sensor located?
Exercise 12b:
How tall (in mm) will Mick be on the sensor?
Exercise 12c:
The camera sensor contains 640
×
×
480 pixels and its physical size is
4
.
8 mm. How tall (in pixels) will Mick be on the sensor?
Exercise 12d:
What are the horizontal field-of-view and the vertical field-of-view
of the camera?
6
.
4mm
×
