Description
The purpose of this homework is to experiment with histogram modification and color processing
Your program should be able to do the following:
1. Histogram modification [4 points]
Add histogram stretching for grey level images to your choice of options
Stretching is defined by user provided intensity range parameters (a, b): stretch the intensities in the range between
a and b on the input image to the range of 0 to 255 as output. [0,a] -> 0, [a,b] -> [0,255], [b,255] -> 255
o Your program should apply the procedure within ROI (up to three ROI as Hw1)
o Generate image of the histograms for the ROI before and after the procedure, this is good for debugging
and illustrations
Test your program on some grey level images
[extra credit – 1 points] Implement general bilinear histogram stretching (parameters of input [a,b], and of output
[c,d]) and discuss performance. [0,a]->[0,c], [a,b]->[c,d] and [b,255]->[d,255]
2. Implement Optimal thresholding algorithm (as discussed in class) [3 points]
Implementation should be within ROIs
Initialize threshold using median (in ROI) value
Test on several grey scale images and ROIs
3. Combining image analysis operations [3 points]
Combine histogram stretching with optimal thresholding by
Performing optimal thresholding within ROI. That will segment ROI into two subregions: Background and
Foreground
Apply histogram stretching to Background and Foreground separately and combine in one image
For histogram stretching use a=min_intensity in the subregion and b=max_intensity in the subregion
Test on several grey scale images and ROIs
[extra credit – 1 point] Perform histogram stretching on both I and S components. How about including all three
I, S and H components? Experiment.
Make sure that you have complete report for this assignment (not just few comments).
Include input and output images (use several gray level images).
Discuss performance of histogram processing on grey level images.
Discuss performance of the thresholding algorithm.
Discuss performance of combined algorithm.
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How to submit
• Submit paper report in class on the due date
• See TA help desk for instruction on program submission and testing.
