Interview Questions.

Q1. What Do You Meant By Zooming Of Digital Images?

Zooming can be considered as over sampling. It involves the introduction of recent pixel places and the mission of grey degrees to those new places.

Q2. Write Any Four Applications Of Dip?

Remote sensing

Image trmission and storage for business software

Medical imaging

Astronomy

Q3. What Do You Meant By Shrinking Of Digital Images?

Shrinking can be regarded as under sampling. To reduce an image by one half of, we delete each row and column. To reduce feasible aliasing effect, it is a great concept to blue an photo slightly before shrinking it.

Q4. Explain Mask Or Kernels?

A Mask is a small -dimensional array, in which the fee of the masks coefficient determines the character of the procedure, consisting of photo polishing.

Q5. Give The Properties Of One-dimensional Dft?

The DFT and unitary DFT matrices are symmetric.

The extensions of the DFT and unitary DFT of a series and their inverse trforms are periodic with duration N.

The DFT or unitary DFT of a actual sequence is conjugate symmetric about N/@

Q6. Write The Expression Of One-dimensional Discrete Fourier Trforms?

Forward trform

The sequence of x(n) is given by way of x(n) =  x0,x1,x2,… xN-1.

X(ok) = (n=0 to N-1) _ x(n) exp(-j 2* pi* nk/N) ; k= 0,1,2,…N-1

Reverse trforms

X(n) = (1/N) (ok=0 to N-1) _ x(ok) exp(-j 2* pi* nk/N) ; n= zero,1,2,…N-1

Q7. What Do You Meant By Gray Level?

Gray stage refers to a scalar degree of depth that ranges from black to grays and finally to white.

Q8. Write Down The Properties Of second Fourier Trform?

Separability

Trlation

Periodicity and Conjugate belongings

Rotation

Distributivity and scaling

Average price

Convolution and Correlation

Laplacian

Q9. Define Averaging Filters?

The output of a smoothing, linear spatial clear out is the average of the pixels contain within the neighborhood of the filter mask. These filters are called averaging filters.

Q10. What Is Image Negatives?

The negative of an photo with gray levels within the variety [0, L-1] is obtained through the usage of the poor trformation, that is given with the aid of the expression.

S = L-1-r

Where s is output pixel.

R is enter pixel.

Q11. What Do You Mean By Point Processing?

Image enhancement at any Point in an image depends simplest on the gray level at that point is frequently referred to as Point processing.

Q12. What Are The Properties Of Slant Trform?

Slant trform is actual and orthogonal.

Slant trform is a quick trform

Slant trform has excellent strength compaction for pics

The primary vectors of Slant matrix are not sequency ordered.

Q13. Define The Term Radiance?

Radiance is the entire amount of power that flows from the light supply, and it also includes measured in watts (w).

Q14. Write The Expression For Hadamard Trforms?

Hadamard trform matrices Hn are NXN matrices wherein N=2^n , n= 1,2,three,… is defined as Hn= Hn-1 * H1 = H1* Hn-1

= 1/ _ 2 Hn-1 Hn-1

H2 = 1 1

1 –1

Q15. What Are The Applications Of Trform?

To lessen band width

To lessen redundancy

To extract function.

Q16. Define Tapered Quantization?

If grey levels in a positive variety arise often whilst others takes place rarely, the quantization degrees are finely spaced in this range and coarsely spaced outside of it.This method is sometimes known as Tapered Quantization.

Q17. Define Mach Band Effect?

The spatial interaction of Luminance from an object and its surround creates a Phenomenon known as the mach band effect.

Q18. What Is The Effect Of Mach Band Pattern?

The depth or the brightness pattern understand a darker stribe in place D and brighter stribe in region B.This impact is known as Mach band pattern or impact.

Q19. Define Image?

An Image may be defined as a two dimensional function f (x,y) in which x & y are spatial (aircraft) coordinates, and the amplitude of f at any pair of coordinates (x,y) is referred to as intensity or grey degree of the picture at that factor. When x,y and the amplitude values of f are all finite, discrete portions we call the photograph as Digital Image.

Q20. Write The Expression To Find The Number Of Bits To Store A Digital Image?

The range of bits required to keep a virtual photo is

b=M X N X okay

When M=N, this equation becomes

b=N^2k

Q21. Write The Properties Of Hadamard Trform?

Hadamard trform carries any individual cost.

No multiplications are required inside the trform calculations.

The no: of additives or subtractions required may be decreased from N^2 to Nlog2N

Very proper energy compaction for exceptionally correlated pix.

Q22. Define Brightness?

Brightness of an object is the perceived luminance of the surround. Two items with extraordinary environment might have equal luminance however distinct brightness.

Q23. Give The Conditions For Perfect Trform?

Trpose of matrix = Inverse of a matrix. Orthoganality.

Q24. What Is Image Enhancement?

Image enhancement is to process an picture so that the output is extra suitable for specific application.

Q25. Explain Spatial Filtering?

Spatial filtering is the process of transferring the filter out mask from factor to factor in an photograph. For linear spatial filter, the reaction is given by means of a sum of merchandise of the clear out coefficients, and the corresponding image pixels within the vicinity spanned by means of the filter out masks.

Q26. Define The Term Luminance?

Luminance measured in lumens (lm), offers a measure of the quantity of strength an observer perceiver from a mild source.

Q27. Justify That Klt Is An Optimal Trform?

Since suggest square mistakes of reconstructed photo and unique photo is minimal and the mean price of trformed picture is zero in order that uncorrelated.

Q28. Properties Of Twiddle Factor?

@Periodicity

WN^(K+N)= WN^K

@Symmetry

WN^(K+N/2)= -WN^K

Q29. What Is Dynamic Range?

The variety of values spanned through the gray scale is referred to as dynamic variety of an picture. Image can have high evaluation, if the dynamic range is excessive and photo may have stupid washed out gray appearance if the dynamic variety is low.

Q30. Define Haar Trform?

The Haar features are defined on a non-stop c programming language Xe [0,1] and for K=zero,1,……. N-1.Where N=2^n. The integer okay can be uniquely decomposed as K=2^P+Q-1.

Q31. What Are The Properties Of Unitary Trform?

Determinant and the Eigen values of a unitary matrix have cohesion significance

The entropy of a random vector is preserved underneath a unitary Trformation

Since the entropy is a degree of common statistics, this me data is preserved underneath a unitary trformation.

Q32. Define Of Kl Trform?

KL Trform is an highest quality within the experience that it minimizes the imply square mistakes among the vectors X and their approximations X^. Due to this concept of using the Eigenvectors corresponding to largest Eigen values. It is likewise referred to as important issue trform.

Q33. Define Image Sampling?

Digitization of spatial coordinates (x,y) is called Image Sampling. To be suitable for pc processing, an picture feature f(x,y) should be digitized each spatially and in importance.

Q34. What Is Maximum Filter And Minimum Filter?

The one hundredth percentile is maximum clear out is used in locating brightest factors in an image. The 0th percentile clear out is minimal clear out used for locating darkest points in an photograph.

Q35. Write The M X N Digital Image In Compact Matrix Form?

F(x,y )= f(0,0) f(zero,1)………………f(0,N-1)

f(1,0) f(1,1)………………f(1,N-1)

.

.

.

F(M-1) f(M-1,1)…………f(M-1,N-1)

Q36. Write The Properties Of Sine Trform?

Real, symmetric and orthogonal.

Not the imaginary part of the unitary DFT.

Fast trform.

Q37. Write Down The Properties Of Haar Trform?

Real and orthogonal

Very speedy trform

Basis vectors are sequentially ordered

Has fair electricity compaction for image

Useful in feature extraction,photograph coding and photo evaluation problem

Q38. Define Quantization ?

Digitizing the amplitude values is known as Quantization. Quality of virtual picture is decided to a large diploma by the range of samples and discrete gray degrees utilized in sampling and quantization.

Q39. What Is A Median Filter?

The median clear out replaces the price of a pixel by way of the median of the gray levels inside the neighborhood of that pixel.

Q40. Explain The Term Digital Image?

The virtual photo is an array of actual or complex numbers this is represented through a finite no of bits.

Q41. Give The Properties Of Two-dimensional Dft?

Symmetric

Periodic extensions

Sampled Fourier trform

Conjugate symmetry.

Q42. Write The Properties Of Cosine Trform?

Real & orthogonal.

Fast trform.

Has excellent strength compaction for noticeably correlated statistics

Q43. Define Derivative Filter?

For a feature f (x, y), the gradient f at co-ordinate (x, y) is described because the

vector_f = _f/_x

_f/_y

_f = mag (_f) = [(_f/_x) 2 +(_f/_y) 2 ] ½

Q44. What Is Cosine Trform?

The NXN cosine trform c(okay) is called the discrete cosine trform and is defined as

C(k) = 1/_N , k=zero, 0 _ n _ N-1 = _ (2/N) cos (pi (2n+1)/2N 1_ ok _ N-1, 0_ n _ N-1

Q45. Name The Categories Of Image Enhancement And Explain?

The classes of Image Enhancement are

Spatial area

Frequency area Spatial area: It refers to the picture plane, itself and it's far primarily based on direct manipulation of pixels of an photograph.

Frequency domain strategies are based totally on modifying the Fourier trform of an photograph.

Q46. Define Resolutions?

Resolution is defined as the smallest wide variety of discernible detail in an photograph. Spatial resolution is the smallest discernible element in an picture and grey level decision refers to the smallest discernible trade is gray level.

Q47. Define Histogram?

The histogram of a virtual photograph with gray ranges in the variety [0, L-1] is a discrete feature h (rk) = nk, in which rk is the kth gray stage and nk is the wide variety of pixels within the image having gray stage rk.

Q48. What Is Image Trform?

An image can be expanded in terms of a discrete set of basis arrays called foundation pix. Unitary matrices can generate those foundation photos. Alternatively, a given NXN image can be regarded as an N^2X1 vectors. An photo trform provides a hard and fast of coordinates or basis vectors for vector area.

Q49. Obtain The Hadamard Trformation For N = four?

        N = 4 = 2n

         => n = 2

Q50. What Are The Properties Of Haar Trform?

Haar trform is real and orthogonal.

Haar trform is a very fast trform

Haar trform has very terrible power compaction for images

The simple vectors of Haar matrix sequency ordered.