grouping the pixel pairs and vice versa

Hello everybody. I found the following codes for grouping the pixels and that works very nice. Can anybody help me to back to the original pixels format. That means i want the pixels values grouping and vice versa.

        %grouping the pixel pairs
        img=imread('C:\Users\Desktop\image\t1.png');
        [rows,cols]=size(img);
        [x,y]=ndgrid(1:rows,1:2:cols);
        ind=sub2ind(size(img),x,y);
        ind_shift=sub2ind(size(img),x,y+1);
        pixels1=img(ind);
        pixels2=img(ind_shift);
        pixels=[pixels1(:) pixels2(:)];
        [row1,cols1]=size(pixels);

[Walter Roberson]

Why are you not just using

pixels1 = img(:, 1:2:end);
pixels2 = img(:, 2:2:end);

?

[Mahmudul Hasan]

Thanks @Walter Roberson. But how do i resize the image or concatenate the image?

[Walter Roberson]

The results pixels1 and pixels2 are arrays that represent images. You can resize images in multiple ways including imresize() . You can concatenate arrays with cat() or horzcat() or vertcat() or []