How to Generate the Following Image Effect (Modulation)?
The image seems to be modulated, namely multiplied by Harmonic Signal along its columns.

This is the MATLAB Code:

mInputImage = im2double(imread('2vE0G.png'));
numRows = size(mInputImage, 1);
numCols = size(mInputImage, 2);

signalFreq = floor(numRows / 1.25);

vModulationSignal = 1 + (0.5 * cos(2 * pi * (signalFreq / numRows) * [0:(numRows - 1)].'));

mOutputImage = bsxfun(@times, mInputImage, vModulationSignal);

figure();
imshow(mOutputImage);


This is the result:



You can play with the parameters.

Enjoy...