RGB to gray pic

I want to convert a RGB picture to a gray one, does anybody know how to do that?

[Rik]

What do you mean with 'summation norm'?

[Rik]

You could also consider the rgb2gray function.

[Image Analyst]

Original question (for when it gets edited away):

I want to convert a RGB picture to a gray one, does anybody know how to do that?

Answer 1

[KALYAN ACHARJYA]

May be, is this to add all channels value to get the particular value

#See Whats going on, same code, just be one line see the Rik's Comments (Prefer & Recommended)

data=imread('1.jpeg');
[r,c,ch]=size(data);
for i=1:r
    for j=1:c
        data1(i,j)=sum(data(i,j,1:3));
    end 
end
imshow(data1,[]);

[Rik]

Or just:

data1=sum(data,3);

[KALYAN ACHARJYA]

yes, I feel so Thanks.