3-D image matrix made from 2-D MRI images

Hi, i´m using this code to make 3-D matrix of 2-D MRI images, but if I load more than 3 images that every image besides firts three and the last one is just black and all values of that matrices are zeros. The images are uint8 format. I tried to trasfer them to double but it didn´t work. Is there some solution or the image matrices can be only three for each other?

clc; clear all; close all;
[Name, Path] = uigetfile('*.*',  'All Files (*.*)','MultiSelect','on');
if ~iscell(Name)  
    Name = {Name};
end
%% matrix
for i = 1:1:length(Name)
    Nazev = Name(1,i);
    Nazev = char(Nazev);
    Img_info = [Path Nazev];
    Img = imread(Img_info);
    Img(:,:,i) = double(rgb2gray(Img));
end

[Ameer Hamza]

If possible, can you attach a few sample images? It will help in figuring out the error.

[Vojtech Raska]

No problem. There are few of them :)

Answer 1

[Ameer Hamza]

You are replacing the value of Img inside the for loop. The matrix is rewritten at the next iteration. Try this

clc; clear all; close all;
[Name, Path] = uigetfile('*.*',  'All Files (*.*)','MultiSelect','on');
if ~iscell(Name)  
    Name = {Name};
end
%% matrix
for i = 1:1:length(Name)
    Nazev = Name(1,i);
    Nazev = char(Nazev);
    Img_info = [Path Nazev];
    Img = imread(Img_info);
    Img_matrix(:,:,i) = rgb2gray(Img);
end

montage(Img_matrix)

[Vojtech Raska]

Stil, it doesn´t work. Images 4-6 are stil black

[Ameer Hamza]

Have you copied my code or tried to modify your own code? The montage command at the end gives following output on my system

which shows all the images are loaded.

[Vojtech Raska]

I used your code and it write me lots of errors. I use matlab version 2016b. Can it be because of that?

Error using images.internal.imageDisplayValidateParams>validateCData (line 115)
Multi-plane image inputs must be RGB images of size MxNx3.

Error in images.internal.imageDisplayValidateParams (line 27)
common_args.CData = validateCData(common_args.CData,image_type);

Error in images.internal.imageDisplayParseInputs (line 78)
common_args = images.internal.imageDisplayValidateParams(common_args);

Error in imshow (line 222)
      images.internal.imageDisplayParseInputs({'Parent','Border','Reduce'},preparsed_varargin{:});

Error in montage (line 152)
    hh = imshow(bigImage, displayRange,parentArgs{:});

[Ameer Hamza]

Which line of code is giving this error. All the functions used in my code are present in R2016b.

[Vojtech Raska]

probably montage. All lines refers to inner funcion of matlab. Without montage this code run normaly just don´t want to load any image after the first three.

[Ameer Hamza]

You can remove montage. What function are your using to check if images are loaded? are you using imshow()?

[Vojtech Raska]

yes just imshow() just to open only one Img.

But even when I open Img at worskpace and look to layers 4+. All valuest at these layers are zeros

[Ameer Hamza]

Can you post your script here, including the part which you are using to check the values.

[Vojtech Raska]

clc; clear all; close all;

[Name, Path] = uigetfile('*.*',  'All Files (*.*)','MultiSelect','on');
if ~iscell(Name)
    Name = {Name};
end

%% matice
for i = 1:1:length(Name)
    Nazev = Name(1,i);
    Nazev = char(Nazev);
    Img_info = [Path Nazev];
    Img = imread(Img_info);
    Img(:,:,i) = rgb2gray(Img);
end

imshow(Img(:,:,4))

And for the values at worspace: I just click on variable Img in workspace and simply scroll down to val(:,:,4) and check them.

[Ameer Hamza]

This is different from the code I posted. The last two lines of for loops are

Img = imread(Img_info);
Img_matrix(:,:,i) = rgb2gray(Img);

Save the images in Img_matrix variable

[Vojtech Raska]

Ok this works. Thank you very much. But stil its wierd that when I used your code with montage part. Than i still had some images in Image_matrix black.

But still thanks

[Ameer Hamza]

Glad to be of help.

[Image Analyst]

Can you please "Accept this answer" to give Ameer reputation points for helping you? Thanks in advance.