The union of 2 images

Let's say I have an image called A and another constant image of the same size how do I get the set union of those 2 images : the union should be of the same size as image A

Note: when I use union function it gives me an error (A and B must be vectors or 'rows' must be specified.)

Answer 1

[Matt J]

the union should be of the same size as image A

Then you have an unconventional definition of a "union". There's no reason they should be the same size. Possibly you want to do a pixel-wise or() operation?

Union = A|B

Otherwise please clarify.

[John Snow]

Union = A|B made the result (all white) instead of the union im looking for.

Here is an example :assuming images B and A are the same size I would like C to have the same size as well

[Matt J]

I can't tell from these images what the relationship between C, A and B is supposed to be. Maybe you mean C=A+B?

The intended operation looks like it's supposed to be independent for each pixel. Can you describe in words for a fixed pixel (i,j) how C(i,j) is generated from A(i,j) and B(i,j)?

[John Snow]

lets say B pixels have a constant value of 0.5 I want all pixels in A image whose pixels are less than 0.5 to become 0.5 for example if A is [ 0.3 0.2 0.6 0.8] C will be [ 0.5 0.5 .6 0.8]

[Matt J]

C=max(A,0.5);

[John Snow]

Thank you very much this works good

Answer 2

[Image Analyst]

Maybe you mean something like this:

% Find dark pixels.
binaryImage = skeletonImage < 50; % Or whatever intensity you want.
% Replace dark pixels with pixels from image B.
C_Image = skeletonImage; % Initialize
C_Image(binaryImage) = B_Image(binaryImage); % Replace.

[John Snow]

This works ok but i think the "C=max(A,0.5);" command is easier from the other anser is easier but thank you very much for your answer