t(I,y+floor(dy),x+floor(dx)) + (dx-floor(dx))*(imageAt(I,y+floor(dy),x+ceil(dx))-imageAt(I,y+floor(dy),x+floor(dx)));
        i2 = imageAt(I,y+ceil(dy),x+floor(dx)) + (dx-floor(dx))*(imageAt(I,y+ceil(dy),x+ceil(dx))-imageAt(I,y+ceil(dy),x+floor(dx)));
        I2(y,x) = i1 + (dy-floor(dy))*(i2-i1);
    <span class="keyword">end</span>
<span class="keyword">end</span>
<span class="keyword">end</span>

<span class="keyword">function</span> i = imageAt(I,y,x)
[w,h] = size(I);
<span class="keyword">if</span> (x 