removed files from the old exercise

Assignment4_211/assignment4.4.m

@@ -1,33 +0,0 @@
-clear; close all; clc;
-
-N = 128;
-n = 0:N-1;
-w1 = 2*pi*0.1;
-w2 = 2*pi*0.15;
-x = cos(w1*n) + cos(w2*n);
-
-% a)
-
-X = fft(x);
-magX = abs(X);
-
-figure;
-stem(n, magX, 'filled');
-xlabel('n');
-ylabel('|X[n]|');
-title('Magnitude Spectrum of x[n]');
-grid on;
-
-% b)
-
-y = hamming(N)' .* x;
-
-Y = fft(y);
-magY = abs(Y);
-
-figure;
-stem(n, magY, 'filled');
-xlabel('n');
-ylabel('|Y[n]|');
-title('Magnitude Spectrum of y[n]');
-grid on;

Assignment4_211/assignment4_1.m

@@ -1,33 +0,0 @@
-clc;
-clear;
-close all;
-
-%% Parameters
-f1 = 2000;
-f2 = 4000;
-f3 = 6000;
-
-f3_rec = -3000
-
-%% Time vectors
-t=0:1e-6:1e-3;
-
-%% Signals
-x = 1+0.5*cos(2*pi*f1*t)+2*sin(2*pi*f2*t)+sin(2*pi*f3*t);
-x1 = 1+0.5*cos(2*pi*f1*t)+2*sin(2*pi*f2*t)+sin(2*pi*f3_rec*t);
-x2 = 1+0.5*cos(2*pi*f1*t)+2*sin(2*pi*f2*t)+sin(2*pi*f3*t);
-
-%% Plot
-figure
-hold on
-
-plot(t, x, 'b', 'LineWidth', 1.5)
-plot(t, x1, 'r', 'LineWidth', 1.5)
-plot(t, x2, '--g', 'LineWidth', 1.5)
-
-grid on
-
-xlabel('Time (ms)')
-ylabel('x(t)')
-
-legend('x(t)', 'x1(t)', 'x2(t)');

Assignment4_211/assignment4_3.m

@@ -1,51 +0,0 @@
-clear; close all; clc;
-
-img = imread('pavian.png'); % Choose any picture you like here
-img = rgb2gray(img);
-
-%% Display image
-figure; subplot(131);
-imshow(img);
-title('Ausgangsbild');
-
-%% FFT
-fft2d = fft2(img);
-
-% Display the FFT image.
-subplot(132);
-imshow(log(fftshift(abs(fft2d))), []);
-title('2D-FFT');
-
-%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
-%%
-
-% Approach: We want to remove the low frequencies (high pass filter) to
-% keep the areas of the image where the lightness changes relative to
-% nearby pixels
-
-% Shift FFT so low frequencies are in the center
-F = fftshift(fft2d);
-
-% Get image size
-[M, N] = size(F);
-
-% Radius of how much to remove
-r = 25;
-
-% We cut out the center of the fft low frequencies
-H = ones(M, N);
-H(M/2-r:M/2+r, N/2-r:N/2+r) = 0;
-
-% Apply filter
-F_filtered = F .* H;
-
-% Shift back
-fft2d = ifftshift(F_filtered);
-
-%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
-
-%% IFFT to obtain filtered image
-img_filtered = ifft2(fft2d);
-subplot(133);
-imshow(real(img_filtered), []);
-title('Gefiltertes Ausgangssignal');