imshow produces error when used in subplot

Hello,

I had a working code using:

figure, imshow(I);

Then I wanted to put all the displayed images into one figure using subplot in this way:

figure;

h = [];

h(1) = subplot(2,4,1); etc.

and calling the image via:

imshow(I,'Parent', h(2))

The problem is that this now produces the error:

"Unable to perform assignment because dot indexing is not supported for variables of this type.

Error in images.internal.basicImageDisplay (line 78)

ax_handle.Colormap = map;

Error in imshow (line 330)

hh = images.internal.basicImageDisplay(fig_handle,ax_handle,..."

Also the image now appears blue and yellow instead of black and white.

Being new to MatLab I can only assume something went wrong with the colormap interfering with multiple images in one figure.

Any help would be appreciated a lot :)

Answer 1

[Ameer Hamza]

From your code, it is not clear how did you assign the 2nd element of vector h. However, I recommend initializing 'h' with 'gobjects'.

Replace

h    = [];

with

h    = gobjects;

[F Sp]

That worked! Thank you a lot! I found the h=[] on this page, that's why I used it

[Image Analyst]

What page gave that incorrect information? Not this one.

[F Sp]

somewhere on MatLab Answers, of course not in this particular question. Thank you guys

Answer 2

[Image Analyst]

You do not need to initialize h to anything, not [] nor gobjects. This works perfectly fine:

figure;
h    = []; % Unnecessary.
h(1) = subplot(2,4,1);
% and calling the image via:
I = imread('peppers.png');
imshow(I,'Parent', h(1))

Just make sure you haven't assigned h to anything in advance, like h is not already a cell array or structure or some other complicated non-numerical variable. If h does already exist when you get to h=[], then it might be a mistake to use the same variable h because setting it to null would blow it away and if you ever needed that original h again you would not have it anymore.

Just make sure whatever index you're using in h exists, like you can't use h(2) if you haven't called h(2) = subplot yet.

[F Sp]

Thank you too! :)