double matrix to image conversion

i have a double matrix i have to convert it to an image

Answer 1

[Cris LaPierre]

How are you trying to view the image?

I suspect you need to use uint8 to first convert your doubles to a value between 0 and 255. See here.

[BHANU SRINIVASA]

i have converted the matrix to uint8 also the image is getting displayed in b/w

Answer 2

[Subhadeep Koley]

Hi, try the code below

% Rescale your matrix in 0-255 range
rescaledMatrix = rescale(yourDoubleMatrix, 0, 255);
% Typecasted to uint8 
rescaledMatrix = uint8(rescaledMatrix); 
% Display your image
figure; imshow(rescaledMatrix, []);

This might help!

[BHANU SRINIVASA]

im getting this kind of image

[Subhadeep Koley]

Can you provide your double matrix as a MAT file? So that I can check the same.

You can generate the MAT file with the following command.

save('yourDoubleMatrix.mat','yourDoubleMatrix');

[BHANU SRINIVASA]

these are the 2 outputs

c1 is the matrix after the encryption

and q is the matrix after decryption

i'm able to display the images in b/w but not in the colored form

[Subhadeep Koley]

Yes, it is expected that you will get an image which looks like grayscale because, when I plot a 3D scatter plot on the R, G, and B channel of your matrix "q", it produce a linear trend of the Red-Green-Blue channel, indicating a high correlation among them.

This means pixel values in the R, G, and B channels are almost the same.

This is the reason why your image appears grayscale, even if it is a matrix of dimension 187x269x3.

[BHANU SRINIVASA]

how can i solve this

[BHANU SRINIVASA]

also how to do this scatter plot

[Subhadeep Koley]

The "q" is generated from "c1" by your algorithm only. Therefore it is not possible for me to comment on how this can be solved.

The code for the 3D scatter plot is below.

close all; clear all;
load q.mat;
r = q(:,:,1);
g = q(:,:,2);
b = q(:,:,3);
plot3(r(:),g(:),b(:),'.');
grid on; box on;
xlabel('Red Channel');
ylabel('Green Channel');
zlabel('Blue Channel');
title('Scatterplot of the Visible Bands');

[BHANU SRINIVASA]

thank u very much i found the defect and got the answer

there was a mistake in the loop