How can i get a RGB values from a picture?
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caner kaya
el 10 de Oct. de 2017
Comentada: DGM
el 2 de Dic. de 2022
Hi,
My goal is to get the RGB values of the image taken with the webcam and I need the matlab code to accomplish this purpose. I am a new matlab user, please help me.
Best regards.
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Walter Roberson
el 10 de Oct. de 2017
See https://www.mathworks.com/help/supportpkg/usbwebcams/ug/acquire-images-from-webcams.html on how to work with webcams.
Once you have done the snapshot(), then just index into the resulting array to get the RGB values. For example,
img(183, 17, :)
would extract the R, G, and B components (in that order) of row 183 column 17 of the image.
13 comentarios
Image Analyst
el 27 de En. de 2021
Editada: Image Analyst
el 27 de En. de 2021
What do you want represented along each axis? LIke R along , G along Y and B along Z?
Like this:
rgbImage = double(imread('peppers.png'));
[r, g, b] = imsplit(rgbImage);
xyz = [r(:), g(:), b(:)];
ptCloud = pointCloud(xyz);
pcshow(ptCloud)
![](https://www.mathworks.com/matlabcentral/answers/uploaded_files/502038/image.png)
Looks pretty much like what you get from colorcloud():
![](https://www.mathworks.com/matlabcentral/answers/uploaded_files/502043/image.png)
Walter Roberson
el 28 de En. de 2021
Your color data can be either 2D or 3D
numFaces = 600;
[x,y,z] = sphere(numFaces);
xyz2d = [x(:), y(:), z(:)];
xyz3d = cat(3,x,y,z);
img = imresize(imread('flamingos.jpg'), [numFaces+1, numFaces+1]);
color_matrix_2d = reshape(img, [], 3);
color_matrix_3d = img;
pcshow(xyz2d, color_matrix_2d); title('data arranged as 2d')
pcshow(xyz3d, color_matrix_3d); title('data arranged as 3d')
Más respuestas (3)
Chad Greene
el 10 de Oct. de 2017
Hi Caner,
A = imread('myimage.jpg');
Then the red layer is the first slice of A, blue is the second slice, and green is the third:
R = A(:,:,1);
G = A(:,:,2);
B = A(:,:,3);
If you need the RGB values of a specific pixel, say, row 22, column 50, it would be:
[R(22,50) G(22,50) B(22,50)]
If you're not sure what the row and column numbers are of the pixel you want, display the image with the image function, then use ginput to click around and get the coordinates you want:
image(A)
[col,row] = ginput
3 comentarios
DGM
el 2 de Dic. de 2022
This does show the RGB values at a specific pixel.
% an image
A = imread('peppers.png');
% split the channels
R = A(:,:,1);
G = A(:,:,2);
B = A(:,:,3);
% address each channel to find the color at (22,50)
[R(22,50) G(22,50) B(22,50)]
% of course, this is the same as
permute(A(22,50,:),[1 3 2])
Image Analyst
el 11 de Oct. de 2017
To build on what the others said, you should look at impixelinfo() which is a function that puts a status bar on your figure that gives you the (x,y) location and RGB values as you mouse over the displayed image.
There is also a function called impixel() that gives you the RGB value but I never use it.
6 comentarios
Bryan Benedict Ordas
el 19 de Dic. de 2019
Hello Guys!
I am also in need of help on getting the RGB values in a multiple images. I was able to know also that you can pick a certain coordinates using your mouse to select the pixel you wanted to obtain the RGB Values. What if I wanted to use this function for multiple pictures? is there a way on looping this activity? (selecting pixels and getting the RGB Values of Multiple Pictures).
My purpose was to gather data of a certain object for neural networks.
Thanks!!!
2 comentarios
Bryan Benedict Ordas
el 19 de Dic. de 2019
I'm new on using Matlab so please be easy on me... hehe, thanks!
Image Analyst
el 19 de Dic. de 2019
See the FAQ for code samples on how to read in multiple images and get their RGB values.
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