Question

I am trying to do edge detection using matlab. I have posted code here. It does not give any error but it's not running it at all. So please help me to fix it and also exaplin each line of this code pls. Thanks!

i = imread('C:\Users\Amanda\Desktop");
I = rgb2gray(1i);
BW1 = edge(I,'prewitt');
BW2= edge(I,'sobel');
BW3= edge(I,'roberts');
subplot (2,2,1);
imshow(I);
title('original');
subplot(2,2,2);
imshow(BW1);
title('Prewitt');
subplot(2,2,3);
imshow(BW2);
title('Sobel');
subplot(2,2,4);
imshow(BW3);
title('Roberts');

Answer 1

I have fixed the code which you posted, there are basically two errors.

1. The name of the initial image file.
2. Use of that 'i' in the second line.

Resolution

1. There are two solutions for the first error.
   1. just paste the image in the same folder as that of the script and directly use the name of image as I have done below.
   2. Otherwise, add the name of the file after the location of the folder it is present in. LIKE: "C://Users//Amanda//Desktop//RGB.png" if the name of the file is RGB.png
2. The second error solution is to simply make the "1i" to "i" (Without quotes)

Following is the updated code

i = imread('RGB.png'); % This is reading the image from the file location specifies

I = rgb2gray(i); % Converting the image from RGB to Gray image

BW1 = edge(I,'prewitt'); % This is finding the edge in the image with prewitt as the method

BW2= edge(I,'sobel'); % This is finding the edge in the image with Sobel as the method

BW3= edge(I,'roberts'); % This is finding the edge in the image with roberts as the method

subplot (2,2,1); % This is making the plot in the area of 2*2 i.e 4 plots and this is the first(1) plot

imshow(I); % This will show the plot, whose space is aquired above, in the above line

title('original'); % Title for the above plot

subplot(2,2,2); % Acquiring space for the second plot

imshow(BW1); % Printing the second one in the space

title('Prewitt'); % Title for the above plot

subplot(2,2,3); % Making the space for the third plot

imshow(BW2); % Printing the third plot, whose space is allocated above.

title('Sobel'); % Title for the above plot

subplot(2,2,4); % Fourth plot Space

imshow(BW3); % Printing the plot

title('Roberts'); % Title for the same.

Following is the snippet of the output.

That was a nice question to answer
Friend, If you have any doubts in understanding do let me know in the comment section. I will be happy to help you further.
Please like if you think effort deserves like.
Thanks

Figure 1 x + original Pre witt Sobel Roberts