How do i save a .tif stack of grayscale or RGB images into a 4d-array like in the "mri example" of MATLAB?

Hi, i want to save a stack of grayscale or RGB images, already converted to one .tif file, into a 4D-array, where the fourth value is the number of the slice, just like in the MATLAB example "mri", to do some analysis, e.g displaying 3-D Contour Slices.

I think in the example they used indexed images, so i already did this:

I = imread('D:\Images\Test\1.tif');

[D, map] = gray2ind(I,255);

imshow(D, map);

Can anybody please help? Thanks in advance.

Answer 1

[Image Analyst]

Use cat(4,)

rgb4D = cat(4, rgbImage1, rgbImage2);

[Mike Schneider]

Thank you very much Image Analyst! Have a nice weekend.

[Mike Schneider]

Hi again, i do have another question and hope that you can help.

How can i adjust the Z-Value in the "cat" function? Right now the images are stacked from 1 to 2 in steps of 1. But what if i want to stack them in steps of e.g. 3? I need this because of a later volume calculation of the patch which i try to create with isosurface. Thank you in advance!

PS: what i tried so far is this:

rgb4D = cat(4, rgbImage1, rgbImage2); rgb4D(:,:,2) = 3*rgb4D(:,:,2)

[Image Analyst]

You just have to keep track of your spatial calibration factors because you can't put data into anything other than a matrix in a plane. So if the spacing between x and y pixels is 1 and the spacing between z pixels is 3 then you just have to keep track of that and multiply the volume in voxels by the spatial calibration factor spacingX*spacingY*spacingZ.

[Mike Schneider]

Thank you very much!

[Anand P]

How did you view your resultant volulme? Were you able to view the volume using the same colors as that of the individual images ?

[Image Analyst]

I did not visualize it. If you wanted to, you could extract one RGB slice image.