Question

1. For this problem, you will use any image . Pick two specific colors of the image in the image.

(a) Load the image, convert to HSV, and display the hue component as a grayscale image. Use this

image to identify the hue of each of the colors you chose and record in your homework.

(b) For each color, use the color hue to perform image segmentation to isolate the specific color in the

chalk. The pixels that are not found to be of this color should be set to a neutral gray color RGB =

[0.5,0.5,0.5].

(c) Include the result for each color. Describe each result in 2-3 sentences. If portions of the image are

included that are not pieces of chalk, explain why they were included.

Answer 1

close all,
clear all,
clc,

ProjectPath = pwd;
ROW = 128; COL=128;

ImagePath = strcat(ProjectPath,'\Leena.jpg');
Orig = imread(ImagePath);
HSVimg = rgb2hsv(Orig);
subplot(1,3,1); imshow(Orig); title('Original Image');
subplot(1,3,2); imshow(HSVimg); title('HSV Image');
[row col] = size(Orig);
Row = uint16(rand*row);
Col = uint16(rand*col);

Phsv_1 = impixel(HSVimg,Col,Row);
Prgb_1 = impixel(Orig,Col,Row);

disp(['Color-1, Pixel (',num2str(Row),' , ',num2str(Col),') RGB Value = ',num2str(Prgb_1)]);
disp(['Color-1, Pixel (',num2str(Row),' , ',num2str(Col),') HSV Comp. = ',num2str(Phsv_1)]);

Row = uint16(rand*row);
Col = uint16(rand*col);

Phsv_2 = impixel(HSVimg,Col,Row);
Prgb_2 = impixel(Orig,Col,Row);

disp(['Color-2, Pixel (',num2str(Row),' , ',num2str(Col),') RGB Value = ',num2str(Prgb_2)]);
disp(['Color-2, Pixel (',num2str(Row),' , ',num2str(Col),') HSV Comp. = ',num2str(Phsv_2)]);
[row col] = size(HSVimg);

for r=1:row
for c=1:col
P = impixel(HSVimg,c,r);
if(P(1)~=Phsv_1(1) && P(1)~=Phsv_2(1) && P(2)~=Phsv_1(2) && P(2)~=Phsv_2(2) && P(3)~=Phsv_1(3) && P(3)~=Phsv_2(3)),
HSVimg(r,c,1)=0.5;
HSVimg(r,c,2)=0.5;
HSVimg(r,c,3)=0.5;
end
end
end
subplot(1,3,3); imshow(HSVimg); title('HSV Image');