Problem 1: WARM-UP

• The goal of this problem is to get familiar with converting a color image to a grayscale one. Please convert the given color image, jpg, to a grayscale image named 1_result.jpg.

• Please also perform horizontal flipping on jpg and output the result as 2_result.jpg.

sample1.jpg

Problem 2: IMAGE ENHANCEMENT

Given gray-level images sample2.jpg, sample3.jpg and sample4.jpg, please follow the instructions below to create several new images.

• Decrease the brightness of jpg by dividing the intensity values by 5 and output the image as 3_result.jpg.
• Increase the brightness of jpg by multiplying the intensity values by 5 and output the image as 4_result.jpg.
• Plot the histograms of jpg, 3_result.jpg and 4_result.jpg. What can you observe from these three histograms?
• Perform global histogram equalization on jpg and output the results as 5_result.jpg.
• Perform local histogram equalization on jpg and output the results as 6_result.jpg.
• Plot the histograms of 5_result.jpg and 6_result.jpg. What is the main difference between local and global histogram equalization?
• Please design a transfer function to enhance jpg as best as you can. Output the result as 7_result.jpg and specify all the parameters.

Show the resultant image(s) and the corresponding histogram(s). Please provide some discussions on the results as well.

Problem 3: NOISE REMOVAL

Given an original image named sample5.jpg and two images corrupted by noise as shown in sample6.jpg and sample7.jpg, please follow the instructions below to create some new images.

• Design proper filters to remove noise from jpg and sample7.jpg, and output the resultant images as 8_result.jpg and 9_result.jpg, respectively.

Please detail the steps of the denoising process and specify all the corresponding parameters. Provide some discussions about the reason why those filters and parameters are chosen.

• Compute the PSNR values of jpg and 9_result.jpg and provide some discussions.

Appendix

Problem 1: WARM-UP sample1.jpg 400560 color

Problem 2: IMAGE ENHANCEMENT sample2.jpg 400560 gray-scale sample3.jpg 400560 gray-scale sample4.jpg 400560 gray-scale

Problem 3: NOISE REMOVAL sample5.jpg 400560 gray-scale sample6.jpg 400560 gray-scale sample7.jpg 400560 gray-scale