First of all, it's probably not a good idea to call your variable Image since image() is a built-in function. I know one is capital and one is not, but still, I would not recommend it.
What is delta1 and delta2? Take the semicolon off and see what the value is. Might scale be an array?
Does the code below work for you?
grayImage = imread('moon.tif');
smallImage = imresize(grayImage, scale, 'bilinear');