MATLAB: Getting pixel values from an image

pixel values

Hello, I am new to Matlab and I have a question concerning getting pixel values of an image. I have a 994×994 image and want to get every pixel value in the row 497. Could you please advise what command(s) I should use? Thank you very much.

I have loaded the image in Matlab with Imtool command and there is a pixel region window in which it shows all the pixel values I need. I am wondering if I could export them in an excel file? Thanks again.

Regards

Best Answer

If your image is stored in I, like from the command

 I = imread('peppers.png');

the Matlab syntax to select the element in row 497, column 1 would be

 x = I(497,1);

and the syntax to select all elements uses the column operator : as a shorthand for 1:end

 x = I(497, :);

Related Solutions

MATLAB: How to get the pixel value and the location in an image

See ginput(). For example, run this

img = imread('pears.png');
imshow(img)
[x, y] = ginput(1);
pixel_values = img(floor(x), floor(y), :);
disp(pixel_values)

MATLAB: Counting Total Number of Pixels by Color in a Segmented Image

Code is in the FAQ: https://matlab.fandom.com/wiki/FAQ#How_can_I_process_a_sequence_of_files.3F

In the for loop over all image files, just index the variables:

numBluePixels(k) = sum(BluePixels(:));

etc.

To check that the sum of blue, red, white, and black pixels is to within some tolerance of the total number of pixels, just sum them up at the bottom of the loop

tolerance = 0.05 * numel(BluePixels); % 5% of the total number of pixels.
if numBluePixels(k) + numWhitePixels(k) + numRedPixels(k) + numBlackPixels(k) > numel(BluePixels) - tolerance
    % The sum is close enough to 90,000
else
    % The sum is not close enough to 90,000 because some pixels were not classified as one of those colors.
end

Best Answer

Related Solutions

MATLAB: How to get the pixel value and the location in an image

MATLAB: Counting Total Number of Pixels by Color in a Segmented Image

Related Question