Description
1. Develop a strategy for storing an image given over a hexagonal tessellation into a 2D array
(I.e. by describing the position of each cell using indices i,j).Then show how to:
a. Compute Euclidian distances
b. Determine 6-adjacency
given only the indices (in the new data structure) of 2 arbitrary pixels. You may assume each
side length of a hexagonal cell is a units.
2. Consider the connected component (cc) labeling algorithm involving single pass of an operator propagating labels and keeping equivalences.
a b c
d p
where p is the pixel under consideration. Explain in the form of a table what happens in the algorithm for all possible states (There are 32 possible states for the 5 binary variables). Also
give an example on a simple image.
3. Determine the value of |P|²/A (perimeter squared, divided by area) for a regular polygon
having N sides and show that it is always greater than the value of |P|²/A that corresponds to a
circle.
4. Consider two points that are d units apart from each other. If we use a (circular) disk
shaped structuring element to make these points connected to each other, what is the minimum radius of the disk (in terms of d) which is used as a closing operator? Justify your answer as clearly as possible?
5. Find the parameters of a forward affine transformation that rotates the input image by 45
degrees clockwise around image center (NR/2,NC/2) and alters the aspect ratio of the rotated
image from 4:3 to 16:9 (width:height).
6. Write a computer program that reads a pgm format image file and applies gamma correction to the input image using a gamma value specified at the command line. You
can simply modify the file example1.c which is part of SGimproV1.2b.zip. Submit c code attached to the rest of your solutions.
Note: vcorrected=(
vuncorrected
vmax
)
γ
. v max and vmax is the maximum gray value in the image.
