MatLab Code to convert half RGB image into gray scale

This Is My Converted Picture...

And Following is the MatLab code ...

imgRGB=imread('mirwise.jpg');

imgGray=rgb2gray(imgRGB);

[r,c,~]=size(imgRGB);

c=round(c/2);

imgSplit=imgRGB;

for i=1:3

imgSplit([1:r],[1:c],i)=imgGray([1:r],[1:c]);

end

imshow(imgSplit)

And Here is my Original RGB Image...