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Correct choice is (d) Checkerboard EFFECT

Best explanation: At greater magnification NEAREST NEIGHBOR INTERPOLATION has the UNDESIRABLE feature that it produces a checkerboard effect.

Right option is (d) Pixel Replication

Best explanation: A special case of nearest neighbor interpolation is Pixel replication and is applicable when we want to increase the size of an IMAGE an integer number of TIMES.

For example, doubling the size of an image is achieved duplicating each column and hence image size gets DOUBLED in the horizontal DIRECTION. Then, we duplicate each row of the enlarged image to double the size in the vertical direction. Similarly, enlarging the image by any integer number of times (TRIPLE, quadruple, and so on) is possible.

Correct CHOICE is (c) Nearest neighbor Interpolation

Explanation: Because we look for the closest pixel in the original image and ASSIGN its GRAY level to the NEW pixel in the grid.

The correct option is (b) Zooming

The explanation is: Suppose that we have an IMAGE of size500*500pixels and we WANT to enlarge it 1.5 times to 750*750pixels.

Creation of new PIXELS: ONE of the easiest ways to visualize zooming is laying an imaginary 750*750 grid over the original image and so there would be less spacing by one pixel in the grid because we are fitting it over a smaller image.

Assignment of gray levels to new locations: In order to perform gray-level assignment for any point in the overlay, we assign its gray level to the new pixel in the grid its closest pixel in the original image.

When the above steps are done with all points in the overlay grid, we expand it to the original specified size to obtain the ZOOMED image.

Right choice is (a) By reducing the high-frequency COMPONENTS of IMAGE by blurring the image

The explanation is: Aliasing corrupts the sampled image by INTRODUCING additional frequency components to the sampled function. So, the principal approach for reducing the aliasing EFFECTS on an image is to REDUCE its high-frequency components by blurring the image prior to sampling.

Correct choice is (b) OVERSAMPLING and Undersampling respectively

The explanation is: Oversampling increases the number of SAMPLE in the image, i.e. like Zooming.

Undersampling decreases the number of SAMPLES in the image, i.e. like SHRINKING.

The CORRECT answer is (a) By INTRODUCING additional frequency components to the sampled function

For EXPLANATION: Aliasing corrupts the sampled image by introducing additional frequency components into the sampled function. These added components are CALLED aliased frequencies.

The correct choice is (c) SHANNON sampling theorem

The explanation: For a band-limited function, Shannon sampling theorem says that “if the function is sampled at a rate EQUAL to or greater than TWICE its HIGHEST frequency, the ORIGINAL function can be recovered from its samples”.

The CORRECT option is (c) Aliasing, if the band-limited functions are undersampled

To explain I would SAY: If the band-limited functions is undersampled, then a PHENOMENON called aliasing corrupts the sampled IMAGE.

The correct choice is (b) NEARLY independent of the number of gray levels used

To EXPLAIN: For IMAGE with high details of the image only a few gray levels MAY be needed.

The CORRECT answer is (a) A function of limited duration whose highest frequency is finite

The EXPLANATION is: Functions whose AREA under the curve is finite can be represented in TERMS of sines and cosines of various frequencies. The highest frequency is determined by the sine/cosine component is the highest “frequency content” of the function. If this highest frequency is finite and that the function is of unlimited duration, then, these functions are called band-limited functions.

Right option is (d) Curves tend to become more vertical as the detail in the IMAGE increases

To elaborate: The curves in isopreference curve tend to become more vertical as the detail in the image increases.

The right side graph SHOWS the same, curve for crowd is nearly vertical.

Correct answer is (c) Larger values for N and K, implies better picture quality

The explanation: POINTS lying on an isopreference curve CORRESPOND to images of equal subjective quality. It was found that the isopreference curves tended to shift right and UPWARD with the DETAILS of the image. So, a shift up and right in the curves simply means larger values for N and k, implying better picture quality.

Right choice is (b) 256*256pixels and 64 gray levels

To EXPLAIN: An image of 128*128pixels shows a pronounced checkerboard pattern, while for 256*256pixels image a minimum gray level of 64 is required to REMOVE false contouring.

Also the EFFECT is quite visible in images displayed using 16 or less uniformly SPACED gray levels.

The CORRECT OPTION is (b) Sampling

Easy explanation: The spatial resolution of an image principally DETERMINE by Sampling.

Correct answer is (d) FALSE contouring

The BEST I can explain: The EFFECT, caused due to insufficient number of gray LEVELS in smooth areas of a digital image, is called false contouring, so called because the ridges resemble topographic CONTOURS in a map.