The image object won't do that. It does linear interpolation between the coordinates of its corners. You need to use a graphics object that has coordinates for each pixel.
The one issue with pcolor is that it only supports colormapped images. If you've got a true color image, it won't work. But you can do the same thing that pcolor does. What it's doing is creating a surface with the ZData set to 0's. So you can replicate that with a truecolor image like so:
img = imread('street1.jpg');
w = size(img,2);
h = size(img,1);
x = sin(linspace(-pi/2,pi/2,w)).^3;
y = (w/h)*sin(linspace(-pi/2,pi/2,h)).^3;
h = surf(x,y,zeros(h,w),img,'EdgeColor','none');
view(2)
axis ij
Just replace the X & Y with your grid.
