21⟩ The smallest discernible change in intensity level is called ____________ a) Intensity Resolution b) Contour c) Saturation d) Contrast
a) Intensity Resolution
Number of bits used to quantise intensity of an image is called intensity resolution.
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57 Image Processing Expert Questions And Answers
22⟩ Write short notes on neighbors of a pixel?
The pixel p at co-ordinates (x, y) has 4 neighbors (ie) 2 horizontal and 2 vertical neighbors whose co-ordinates is given by (x+1, y), (x-1,y), (x,y-1), (x, y+1). This is called as direct neighbors. It is denoted by N4(P)
Four diagonal neighbors of p have co-ordinates (x+1, y+1), (x+1,y-1), (x-1, y-1),
(x-1, y+1). It is denoted by ND(4).
Eight neighbors of p denoted by N8(P) is a combination of 4 direct neighbors and 4 diagonal neighbors.
23⟩ What is geometric transformation?
Transformation is used to alter the co-ordinate description of image.
The basic geometric transformations are
1. Image translation
2. Scaling
3. Image rotation
24⟩ The transition between continuous values of the image function and its digital equivalent is called ______________ a) Quantisation b) Sampling c) Rasterisation d) None of the Mentioned
a) Quantisation
The transition between continuous values of the image function and its digital equivalent is called Quantisation.
25⟩ Specify the elements of DIP system?
1. Image Acquisition
2. Storage
3. Processing
4. Display
26⟩ The type of Interpolation where the intensity of the FOUR neighbouring pixels is used to obtain intensity a new location is called ___________ a) cubic interpolation b) nearest neighbour interpolation c) bilinear interpolation d) bicubic interpolation
b) nearest neighbour interpolation
Bilinear interpolation is where the FOUR neighbouring pixels is used to estimate intensity for a new location.
27⟩ What is Hue and saturation?
Hue is a color attribute that describes a pure color where saturation gives a measure of the degree to which a pure color is diluted by white light.
28⟩ What is Luminance?
Luminance measured in lumens (lm), gives a measure of the amount of energy an observer perceiver from a light source.
29⟩ What is recognition and Interpretation?
Recognition means is a process that assigns a label to an object based on the information provided by its descriptors.Interpretation means assigning meaning to a recognized object.
30⟩ What is meant by pixel?
A digital image is composed of a finite number of elements each of which has a particular location or value. These elements are referred to as pixels or image elements or picture elements or pixls elements.
31⟩ Dynamic range of imaging system is a ratio where the upper limit is determined by a) Saturation b) Noise c) Brightness d) Contrast
a) Saturation
Saturation is taken as the Numerator.
32⟩ What is Image Transform?
An image can be expanded in terms of a discrete set of basis arrays called basis images. These basis images can be generated by unitary matrices. Alternatively, a given NxN image can be viewed as an N^2×1 vectors. An image transform provides a set of coordinates or basis vectors for vector space.
33⟩ What is the tool used in tasks such as zooming, shrinking, rotating, etc.? a) Sampling b) Interpolation c) Filters d) None of the Mentioned
b) Interpolation
Interpolation is the basic tool used for zooming, shrinking, rotating, etc.
34⟩ What is simultaneous contrast?
The region reserved brightness not depend on its intensity but also on its background. All centre square have same intensity. However they appear to the eye to become darker as the background becomes lighter.
35⟩ What is weber ratio?
The ratio of increment of illumination to background of illumination is called as weber ratio.(ie) ?i/i
If the ratio (?i/i) is small, then small percentage of change in intensity is needed (ie) good brightness adaptation.
If the ratio (?i/i) is large , then large percentage of change in intensity is needed (ie) poor brightness adaptation.
36⟩ Find the number of bits required to store a 256 X 256 image with 32 gray levels?
32 gray levels = 25
= 5 bits
256 * 256 * 5 = 327680 bits.
37⟩ Explain what are the differences between the books Digital Image Processing and Digital Image Processing?
Difference between the books is that Digital Image Processing (DIP) deals primarily with the theoretical foundation of digital image processing, while Digital Image Processing Using MATLAB (DIPUM) is a book whose main focus is the use of MATLAB for image processing. The DIPUM book covers essentially the same topics as DIP, but the theoretical treatment is not as detailed. Some instructors prefer to fill in the theoretical details in class in favor of having available a book with a strong emphasis on implementation.
38⟩ What do you meant by Gray level?
Gray level refers to a scalar measure of intensity that ranges from black to grays and finally to white.
39⟩ How to increase the quality of an image?
Image enhancement process is purely dependent on the application where we need to use the enhanced image and the type of degradation in the image. Few solutions from my basic knowledge
1. If image contain so much noises, apply filtering operations such as mean/median etc.
2. If the image is looking too dark or or too bright apply histogram equilization process to improve the contrast.
3. If the image is blurred apply sharpening operations in the image.
40⟩ What is meant by path?
Path from pixel p with co-ordinates (x, y) to pixel q with co-ordinates (s,t) is a
sequence of distinct pixels with co-ordinates.
35. Give the formula for calculating D4 and D8 distance.
D4 distance ( city block distance) is defined by
D4(p, q) = |x-s| + |y-t|
D8 distance(chess board distance) is defined by
D8(p, q) = max(|x-s|, |y-t|).
