Digital image processing Examination 2
1. Calculate the value of the center pixel (gray background) using a. Average filter
b. Median filter
c. Laplace filter, where the center coefficient is 8 d. Laplace filter, where the center coefficient is –4
e. If the original pixel values are of UINT-type, what kind of problems may arise with filtering ?
Present how you calculated you answer, not just the final result.
(1p each)
2. Here you see a frequency domain presentation of an image.
a. How are the frequencies organized ? Where is the zero frequency ? b. What does the zero frequency tells us about the spatial domain image ? c. How do you obtain ideal low pass filtering ?
d. How do you obtain gaussian high pass filtering ?
e. What is the essential difference between ideal, Butterworth and Gaussian filters ?
CONTINUES ON THE NEXT PAGE !!!
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3. Color image processing. Answer briefly (1p each).
a. Why it is useful to use color images ? b. How does human eye perceive colors ? c. What is RGB ?
d. What is CMY ?
e. In what applications RGB and CMY are used, respectively ?
4. Explain the process of image restoration using the Fourier transform and convolution theorem. (5p)
That’s it. Thank you for your participation in this course, have a safe trip home and good luck for the future ☺
Jukka
