How can i know my first image is master image and second image my current image how can i find the noise raito between this two images.

[Walter Roberson]

It is never possible to reliably tell whether a single image is noisy or is instead an exact reproduction of a complicated scene.

That picture appears to have a lot of speckle noise, but maybe the materials used had a lot of mica and glitter paint and it might be an excellent picture of what is really there.

[Walter Roberson]

Note that it would be easier for people to experiment if you were to post those as separate images instead of as one pair.

[Walter Roberson]

See immse

Answer 1

[Drishti]

Hi Shri.s,

To distinguish between the master image and the current image, you can perform statistical analysis, including histogram analysis.

Introducing noise to an image will typically result in a distinct change in the histogram, differentiating it from the original, noise-free version.

You can refer to the MATLAB Documentation of ‘imhist’ function for producing histogram of image data.

https://www.mathworks.com/help/releases/R2024a/images/ref/imhist.html

Furthermore, the noise ratio can be calculated by utilizing the difference of standard deviation between the images.

Refer to the implemented work around for better understanding:

% Calculate the difference image
difference_image = abs(double(master_image) - double(current_image1));
% Calculate noise level (standard deviation of the difference image)
noise_level = std(difference_image(:));
% Calculate signal level (mean of the master image)
signal_level = mean(double(master_image(:)));
% Calculate noise ratio
noise_ratio = noise_level / signal_level;

Refer to the MATLAB Documentation of ‘std’ function and ‘mean’ function:

• ‘std’: https://www.mathworks.com/help/releases/R2024a/matlab/ref/std.html
• ‘mean’: https://www.mathworks.com/help/releases/R2024a/matlab/ref/mean.html

I hope this provides a helpful starting point for developing a solution.