function [imout] = preNetNorm(imin)
imin = im2double(imin);
u = [0.485, 0.456, 0.406];
st =[0.229, 0.224, 0.225];
for i = 1:3
U(:,:,i) = ones(size(imin,1),size(imin,2)).*u(i);
ST(:,:,i) = ones(size(imin,1),size(imin,2)).*st(i);
end
imnorm = (imin - U) ./ ST;
imsize = imresize(imnorm,[250,250]);
targetSize = [224 224];
win1 = centerCropWindow2d(size(imsize),targetSize);
imout = imcrop(imsize,win1);