Downsample for 3 different scales

Hey, I want to downsample for 3 different scales as described below:

1/2 in the rows and 1/4 in the columns

1/4 in the rows and 1/2 in the columns

1/8 in rows and 1/8 in columns

How can I use the imresize function? For example:

downNearest=imresize(img, 1/2, 1/4, ....)

Answer 1

[Dave B]

To use imresize with uneven width and height specify the target number of rows and columns:

im=imread('peppers.png');
nr = height(im);
nc = width(im);

im_2_4=imresize(im,[nr/2 nc/4]);
im_4_2=imresize(im,[nr/4 nc/2]);
im_8_8=imresize(im,[nr/8 nc/8]);  % or imresize(im,1/8);

size(im)

ans = 1×3

384 512 3

size(im_2_4)

ans = 1×3

192 128 3

size(im_4_2)

ans = 1×3

96 256 3

size(im_8_8)

ans = 1×3

48 64 3

If you want to use nearest neighbor interpolation when resizing, simply append nearest to the command as follows:

imresize(im,[nr/2 nc/4],'nearest');