Hello,
i copy code for RGB image from jpg
i dont not understand this in bold what is the use of this?

a=imread('C:\Users\user\Pictures\rg.jpg');

subplot('2,2,1');
imshow(a);
R=a;
G=a;
B=a;
R( : ,:,2:3)=0;

 

Hello,

Have a look at this:
https://www.tutorialspoint.com/matlab/matlab_colon_notation.htm
More about Matlab can be found here:
https://www.tutorialspoint.com/matlab/index.htm

Bertus

 

R, G, and B are simply three matricies that are created and assigned the same values as the matrix a.

Usually, in the context of colour graphics application, the letters R, G, and B would be used to represent the three colours red, green, and blue.

Assuming that each of the variables are 3-dimensional matricies containing the same image using jpg format, the last statement is setting all pixels in the green and blue layers to 0. Hence the R matrix will display the image in red colour only.

 

Hello,

Also the following PDF might be of interest:
https://archive.org/download/PRACTI...IDEO_PROCESSING_USING_MATLAB_978111093467.pdf

Bertus

 

here is total code...

a=imread('C:\Users\user\Pictures\rg.jpg');

subplot('2,2,1');
imshow(a);
R=a;
G=a;
B=a;
R(:,:,2:3)=0;
subplot('2,2,2');
imshow(R);
G(:,:,1)=0;
G(:,:,3)=0;
subplot('2,2,3');
imshow(G);
B(:,:,2)=0;
subplot(2,2,4);
imshow(B);

the last statement is setting all pixels in the green and blue layers to 0. Hence the R matrix will display the image in red colour only.

ok, in rgb the 3 matrix are in which sequence first secound third..?

 

Hello,

I do not know matlab, but as I see the code it looks like that it shows 4 images.
1) the complete image
2) the red extracted image
3) the green extracted image
4) the blue extracted image.

Bertus

PS others, please correct me if I am wrong.

 

yes, sir i have run in Matlab interesting software....

 

here is total code...

a=imread('C:\Users\user\Pictures\rg.jpg');

subplot('2,2,1');
imshow(a);
R=a;
G=a;
B=a;
R(:,:,2:3)=0;
subplot('2,2,2');
imshow(R);
G(:,:,1)=0;
G(:,:,3)=0;
subplot('2,2,3');
imshow(G);
B(:,:,2)=0;
subplot(2,2,4);
imshow(B);

ok, in rgb the 3 matrix are in which sequence first secound third..?

The original file is an image in jpg format. This is three layers of x,y pixels.
The first layer is red. The second layer is green. The third layer is blue.
The R, G, and B matrices have specific layers reset to zero so that the R matrix is red, G matrix is green, and B matrix is blue.

 

hello,
this code make matrix color how to get black and white color display in first matrix?

 

For gray scale, set the R,G,B layers to the same values.
btw, there is an error in line 15, shown corrected in the code below:

a=imread('C:\Users\user\Pictures\rg.jpg');

subplot('2,2,1');
imshow(a);
R=a;
G=a;
B=a;
R(:,:,2:3)=0;
subplot('2,2,2');
imshow(R);
G(:,:,1)=0;
G(:,:,3)=0;
subplot('2,2,3');
imshow(G);
B(:,:,1:2)=0;
subplot(2,2,4);
imshow(B);
R(:,:,2)= R(:,:,1);
R(:,:,3)= R(:,:,1);
subplot(2,2,2);
imshow(R);

 

what is wrong in this code?
cant display canny edge detection

a=imread('C:\Users\user\Pictures\gray.png');
subplot(2,2,1);
imshow(a);
bb=edge(a, 'canny');   % here showing error 
subplot(2,2,2);
imshow(bb);

 

What is the error?
Did you read the requirements of the edge( ) function?
Convert the a matrix to a 2-dimensional matrix.

 

ok