Open .mat file containing images

Hi, I am trying to open a .mat folder that contains 2 objects: IMG1N and IMG2. Object IMG1N has 12 images that I need to perform contrast-noise-ratio analysis on. However, I haven't been able to extract and use the 12 images. I have been searching the internet but I dont understand how. This is one of the codes I tried.

allimages = load('A1images.mat')

whos
image(allimages.IMG1N)
colormap(allimages.map)

And this is the result I have been getting

allimages = 

  struct with fields:

    IMG1N: [256×256×12 double]
     IMG2: [300×400 double]

  Name           Size              Bytes  Class     Attributes

  allimages      1x1             7251808  struct              

Error using image
Color data must be an m-by-n-by-3 or m-by-n matrix.

Error in untitled (line 8)
image(allimages.IMG1N)
 

Please help , I do think it's probably a very simple solution but I just can't figure how.

Answer 1

[ILoveMATLAB]

Image() fucntion requires either an m-by-n-by-3 or m-by-n. When you write

image(allimages.IMG1N)

you are giving the image function an m by n by 12 array

If you want to view one of the images, you must call image like this

image(allimages.IMG1N(:,:,1));

If you have the image processing tool box, you should use imshow.

imshow(allimages.IMG1N(:,:,1));

If you want to view the other images, just change the number 1 to the image you want to view.

[Walter Roberson]

I disagree about the use of the word "should" about imshow(). My recommendation is to use imshow() only for interactive exploration or very basic tools, and to get rid of it as soon as your GUI has any meaningful complexity. imshow() does a lot behind your back that can badly interfere with GUI development.

[Walter Roberson]

If the images are intended to be a sequence rather than a volume, then you could consider using implay() to animate them.