Image segmentation

Region based segmentation is to partition an image in to regions based on

• similarities and discontinuities

• neither similarities nor discontinuities

• Similarities

• discontinuities

Edge based segmentation is to partition an image in to regions based on

• similarities and discontinuities

• neither similarities nor discontinuities

• Similarities

• discontinuities

Let R represent the entire spatial region occupied by an image, Segment R into n sub regions R1 ,R2 ,....Rn , such that,

Identify the correct statements from below

1)Ri ∩ Rj  = ϕ ,for all i and j, i ≠ j

2)Q(Ri ) = True ,for i = 1,2,...n

3) Q(Ri U Rj) = True, for any adjacent regions Ri and Rj

• only 1 is correct

• only 1 & 3 are correct

• only 2 & 3 are correct

• only 1 & 2 are correct

Let R represent the entire spatial region occupied by an image, Segment R into n sub regions R1 ,R2 ,....Rn , such that,

Identify the false statement

• Ri ∩ Rj  = ϕ ,for all i and j, i ≠ j

• Q(Ri ) = False ,

  for i = 1,2,...n

• Q(Ri U Rj) = False, for any adjacent regions Ri and Rj

• All of the above are false

First order derivatives generally produce ______ in an image.

• thin edges

• thicker edges

• Double edge

• Option 1 & 3 are correct

Second order derivatives generally produce ______ in an image.

• thin edges

• thicker edges

• Double edge

• Option 1 & 3 are correct

A ______ involves a transition between two intensity levels occurring ideally over the distance of one pixel.

• line

• roof edge

• ramp edge

• step edge

The tool of choice for finding edge strength and direction at location (x,y) of image ‘f’, is the gradient of ‘f’ and defined as vector is___

• Averaging Filter

• The Laplacian operator

• The Gradient operator

• Median Filter

The image Gradient vector points in the direction of the _____ rate of change of ‘f’ at location (x,y)

• Smallest

• greatest

• zero

• equal

______ the histogram of an image can be used for segmenting image into sub regions.

• Thresholding

• Streching

• Enhancing

• Filtering