- What is the result of size(im) ?
- When you say you want to "add these values to the image" do you mean you want to concatenate them (as mentioned in your title) and if so, where should that vector be inserted?
concatenating arrays and matrix
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Hi all I trying to get a simple syntax to add this constant to image values
im=imread(im)
im=rgb2gray(im)
so now that im is now the gray scale image
i am try to add these values to the image
C1=[10,20,50,100]
Can profesional provide an example of how this is done in the simplest form using a for loop?
thank you in advance!!!
7 Comments
Adam Danz
on 16 Aug 2019
Edited: Adam Danz
on 16 Aug 2019
If your array is 5 x 5 you cannot concatenate a vector with only 4 elements!
Concatenation involves joining two arrays. Here are two examples.
% Horizontal concatenation
A = [1 2 3;
4 5 6];
B = [11 12 13;
14 15 16];
C = [A,B]
C =
1 2 3 11 12 13
4 5 6 14 15 16
% Vertical concatenation
C = [A; B]
C =
1 2 3
4 5 6
11 12 13
14 15 16
Notice that the size of A and B are equal in the dimensions being concatenated. Here's an example that would FAIL.
X = [1 2 3];
Y = [1 2 3 4];
Z = [X,Y]; % This works
Z2 = [X; Y]; % This doesn't work!
To learn more:
Accepted Answer
Walter Roberson
on 16 Aug 2019
Borrow my code from your previous question https://www.mathworks.com/matlabcentral/answers/475006-threshold-multiple-values-at-the-same-time which had
nd = ndims(YourImageArray);
Thresholded_arrays = bsxfun(@le, YourImageArray, reshape([50, 100, 150, 200], [ones(1,nd), 4]) );
Instead of @le you would use @plus
nd = ndims(YourImageArray);
Incremented_arrays = bsxfun(@plus, YourImageArray, reshape(uint8([50, 100, 150, 200]), [ones(1,nd), 4]) );
5 Comments
Walter Roberson
on 17 Aug 2019
C1 = [10,20,50,100];
numC1 = length(C1);
imrgb = imread(FILENAME);
imgray = rgb2gray(imrgb);
[r, c] = size(imgray);
output = zeros(r, c, numC1, class(imgray)); %probably it will be uint8
for C1idx = 1 : numC1
this_C1 = C1(C1idx);
output(:,:,C1idx) = imgray + this_C1;
end
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