matlab - image Normalization, image Range and image Scaling for different stack of images

I am so confused with image Normalization, and image Range, and image Scaling.
I am using an algorithm (I have upload the algorithm in my Previous Question), and after applying the algorithm I am using this formula from wikipedia to normalize the images:

using getrangefromclass(filtImag1{i}) from MATLAB, the range of matrices before applying the algorithm is [0 255] and after applying the algorithm the range is [0 1].

the problem is I need to find a reference to find out if the normalization formula is correct or not? also I have 5 stacks of images each containing 600 images. I have applied the algorithm for each stack, and because the result of algorithm is 10 images for each stack, I will end up with 50 images that I need to analysis and compare them together. I find the max and the min of the 50 images , and then pass each image into the formula to normalize the image.

although the range of the images is [0 1] but the max of the image is :
max = 3.6714e+004

why? shouldn't it be 1?

is this the right way of normalization?
how can I apply scaling ? do I need to do it?

here is the normalization code :

%%%%%%%%%%%%%%Find Min and Max between the results%%%%%%%%%%%%%%%%%%%%%%% 
pre_max = max(filtImag1{1}(:));
for i=1:10
   new_max = max(filtImag1{i}(:));
    if (pre_max
        pre_max=max(filtImag1{i}(:));
    end
end
new_max = pre_max;

pre_min = min(filtImag1{1}(:));
for i=1:10
   new_min = min(filtImag1{i}(:));
    if (pre_min>new_min)
        pre_min = min(filtImag1{i}(:));

    end
end
new_min = pre_min;

%%%%%%%%%%%%%%normalization %%%%%%%%%%%%%%%%%%%%%%%
 for i=1:10
 temp_imag = filtImag1{i}(:,:);
 x=isnan(temp_imag);
 temp_imag(x)=0;
 t_max = max(max(temp_imag));

 t_min = min(min(temp_imag));
 temp_imag = (double(temp_imag-t_min)).*((double(new_max)-double(new_min))/double(t_max-t_min))+(double(new_min));
 imag_test2{i}(:,:) = temp_imag;
 end

EDIT
I have change the code based on suggested answers but the result is black image

%find the max and min between them

pre_max = max(sTStack{1}(:));
for i=1:40
newMax = max(sTStack{i}(:));
if (pre_max

pre_min = min(sTStack{1}(:));
for i=1:40
newMin = min(sTStack{i}(:));
if (pre_min>newMin)
pre_min = min(sTStack{i}(:));

end
end
t_min = pre_min;

%%%%%%%%%%%%%%%%%%%%%%% Normalize the Image:%%%%%%%%%%%%%%%%%%%%%%%%%%%%

for i=1:40
NTstack{i} = (sTStack{i} - t_min)/(t_max-t_min);
end

for i=10:10:40
figure,imshow(NTstack{i});
colorbar
colormap jet
end