How to change the size of a image, which is saved as a .mat file?

load e15802s13_P50176.7.h5.mat;

I have this image. I want to change the size/dimension of the image from this mat file. How can I do that?

[yanqi liu]

yes，sir，may be upload your mat file to analysis

[Gulfam Saju]

This is the file

[Walter Roberson]

That file contains a single variable that is 20 x 640 x 20 x 640 . How would you like to resize it or change its dimension?

[Gulfam Saju]

I want the dimension to be 256*256*8

[Walter Roberson]

Your input has:

• input dimension #1 has size 20
• input dimension #2 has size 640
• input dimension #3 has size 20
• input dimension #4 has size 640

You want 256 x 256 x 8 output.

Which of the input dimensions should correspond to your output dimension #1, size 256?

Which of the input dimensions should correspond to your output dimension #2, size 256?

Which of the input dimensions should correspond to your output dimension #3, size 8?

What should happen to the 4th input dimension? For example are you wanting to take mean() over a dimension? max() over a dimension ("Maximum Projection" is a real thing and sometimes very useful) ?

Answer 1

[DGM]

Since a .mat file can contain any number of things, I'm going to have to assume that:

• you know what's in the file and how to open it
• the content is something which can be handled with existing image processing tools
• you know how you want to save the file and how to save it

... in which case the answer is incredibly generic:

Open the file, resize the image(s) with imresize(), and then save the result in whatever way you intend.

[Walter Roberson]

If the .mat file contains a figure that has an image displayed inside it, then you can use imhandles() https://www.mathworks.com/help/images/ref/imhandles.html on the figure to get the handles of the image() objects. Then you can access the CData property to get the data.

(You might also need to cmap = colormap(ancestor(ImageHandle, 'axes')) in order to get the color map. And in some cases you might need to caxis(ancestor(ImageHandle, 'axes')) in order fetch the color mapping properties.)