21. How a degradation process is modeled?

22.Give the homogenity property in Linear Operator

23. Give the relation for degradation model for continuous function

 24.which is called the superposition or convolution or fredholm integral of first kind. 

25. Define circulant matrix

26. What is the concept algebraic approach?

27. What are the two methods of algebraic approach?

28. Define Gray-level interpolation

29. What is meant by Noise probability density function?

30. Why the restoration is called as unconstrained restoration?