Description
PART A
Develop a computer program that reads RGB images from “PPM” format image files and blurs one or
more of the R,G,B components using a Gaussian filter. Gaussian filter masks with different support
sizes should be generated from sequential application of the weighted averaging filter that
approximates Gaussian filter: [1 2 1]. This filter should be applied to rows and columns (recall
separability property of Gaussian filter) to create the same effect as the filter:
1 2 1
2 4 2
1 2 1
The procedure described above should be repeated as many times as it is necessary to create the
desired filter support.
The name of the executable program should be “rgbgauss.exe”. It should take five arguments:
rgbgauss [Rflag] [Gflag] [Bflag] [num. of iter.] [ppm file]
Three flag variables take values 0 and 1. For instance, if Rflag takes the value “0” the R component of
the image is not filtered. If it takes the value “1” the R component is filtered as described above. G and
B components are also filtered similarly. If all flag values are 1’s, the output should be a blurred color
image. If only one or two of the flags are 1, you should observe an interesting glowing artifact.
Number of iterations entered in the command line may actually be considered as the radius of the
effective Gaussian filter mask.
PART B
Implement a modified vector approach to color edge detection (similar to the method discussed at the
end of the “color” lecture.) This program should calculate the edge magnitudes as described in class
and display them in a color scale which is determined by the values entered in the command line. The
colors displayed should be controlled in HSI space. The highest gradient magnitude in the image
should be displayed by red hue, the lowest (above threshold) should be displayed by blue and the
values in between should be represented by the colors between blue and red (hint: consider the circular
arcs in the color gamut for fixed saturation and intensity values).
The name of the executable program should be “color_edge.exe”. It should take three arguments:
color_edge [variable 1] [variable 2] [variable 3]
[variable 1] is a threshold value. Edge magnitude values under the threshold value should be
displayed as black (or white if you wish) pixels. [variable 2] and [variable 3] are the
desired saturation and intensity values.
Please submit 2 c files (GroupNo)hw3parta.c (GroupNo)hw3partb.c packed in (GroupNo)hw3.zip
