diff --git a/03_spectral_images/01_discrete_fourier_transform.ipynb b/03_spectral_images/01_discrete_fourier_transform.ipynb
index bb2f4eaa33c4ccd7343103f3cb566d1eff3ef5dd..cc3b080f4874e98068843dc4beffa92ccd105fb7 100644
--- a/03_spectral_images/01_discrete_fourier_transform.ipynb
+++ b/03_spectral_images/01_discrete_fourier_transform.ipynb
@@ -15,7 +15,6 @@
    "source": [
     "### Teil 1\n",
     "Visualisieren Sie die Fouriertransformierteder Bilder square.png, rectangle.png und circle.png.\n",
-    "\n",
     "Orientieren Sie sich hierbei am [OpenCV Tutorial zur Diskreten Fourier Transformation](https://docs.opencv.org/4.5.0/d8/d01/tutorial_discrete_fourier_transform.html)."
    ]
   },
@@ -46,9 +45,10 @@
     "%matplotlib inline\n",
     "from matplotlib import pyplot as plt\n",
     "\n",
-    "def fourier(img):\n",
+    "def fourier_transform(img):\n",
     "    \n",
-    "    # TODO: implementieren Sie die Fourier Transformation wie im Tutorial\n",
+    "    # TODO: Implementieren Sie die Fourier-Transformation wie im OpenCV Tutorial geben Sie das ergebnis mittels \n",
+    "    # des returns zurück\n",
     "    \n",
     "    return img\n",
     "\n",
@@ -60,15 +60,15 @@
     "fig, axs = plt.subplots(2, 3, figsize = (14, 10))\n",
     "_ = axs[0, 0].imshow(img_square, cmap = 'gray')\n",
     "_ = axs[0, 0].set_title('Square')\n",
-    "_ = axs[1, 0].imshow(fourier(img_square), cmap = 'gray')\n",
+    "_ = axs[1, 0].imshow(fourier_transform(img_square), cmap = 'gray')\n",
     "_ = axs[1, 0].set_title('Square Fourier')\n",
     "_ = axs[0, 1].imshow(img_rectangle, cmap = 'gray')\n",
     "_ = axs[0, 1].set_title('Rectangle')\n",
-    "_ = axs[1, 1].imshow(fourier(img_rectangle), cmap = 'gray')\n",
+    "_ = axs[1, 1].imshow(fourier_transform(img_rectangle), cmap = 'gray')\n",
     "_ = axs[1, 1].set_title('Rectangle Fourier')\n",
     "_ = axs[0, 2].imshow(img_circle, cmap = 'gray')\n",
     "_ = axs[0, 2].set_title('Circle')\n",
-    "_ = axs[1, 2].imshow(fourier(img_circle), cmap = 'gray')\n",
+    "_ = axs[1, 2].imshow(fourier_transform(img_circle), cmap = 'gray')\n",
     "_ = axs[1, 2].set_title('Circle Fourier')"
    ]
   },
@@ -100,9 +100,10 @@
     }
    ],
    "source": [
-    "def high_pass(img, size):    \n",
-    "    \n",
-    "    # TODO: implementieren Sie den Hochpassfilter mit size um die Frequenzen zu filtern\n",
+    "def high_pass(img, frequency):\n",
+    "\n",
+    "    # TODO: Implementieren Sie die Anwendung des Hochpassfilters und geben Sie das Ergebnis mittels\n",
+    "    # des returns zurück. Dabei sollen alle Frequenzen kleiner als frequency gefiltert werden\n",
     "\n",
     "    return img\n",
     "\n",
@@ -112,11 +113,11 @@
     "fig, axs = plt.subplots(2, 2, figsize = (16, 10))\n",
     "_ = axs[0, 0].imshow(img_fh, cmap = 'gray')\n",
     "_ = axs[0, 0].set_title('FH')\n",
-    "_ = axs[1, 0].imshow(high_pass(img_fh, 50), cmap = 'gray')\n",
+    "_ = axs[1, 0].imshow(high_pass(img_fh, -25000), cmap = 'gray')\n",
     "_ = axs[1, 0].set_title('FH High Pass')\n",
     "_ = axs[0, 1].imshow(img_jahrmarkt, cmap = 'gray')\n",
     "_ = axs[0, 1].set_title('Jahrmarkt')\n",
-    "_ = axs[1, 1].imshow(high_pass(img_jahrmarkt, 30), cmap = 'gray')\n",
+    "_ = axs[1, 1].imshow(high_pass(img_jahrmarkt, -40000), cmap = 'gray')\n",
     "_ = axs[1, 1].set_title('Jahrmarkt High Pass')"
    ]
   },
@@ -148,20 +149,21 @@
     }
    ],
    "source": [
-    "def low_pass(img, size):\n",
+    "def low_pass(img, frequency):\n",
     "    \n",
-    "    # TODO: implementieren Sie den Tiefpassfilter mit size um die Frequenzen zu filtern\n",
+    "    # TODO: Implementieren Sie die Anwendung des Tiefpassfilters und geben Sie das Ergebnis mittels\n",
+    "    # des returns zurück. Dabei sollen alle Frequenzen größer als frequency gefiltert werden\n",
     "\n",
     "    return img\n",
     "\n",
     "fig, axs = plt.subplots(2, 2, figsize = (16, 10))\n",
     "_ = axs[0, 0].imshow(img_fh, cmap = 'gray')\n",
     "_ = axs[0, 0].set_title('FH')\n",
-    "_ = axs[1, 0].imshow(low_pass(img_fh, 40), cmap = 'gray')\n",
+    "_ = axs[1, 0].imshow(low_pass(img_fh, 400000), cmap = 'gray')\n",
     "_ = axs[1, 0].set_title('FH Low Pass')\n",
     "_ = axs[0, 1].imshow(img_jahrmarkt, cmap = 'gray')\n",
     "_ = axs[0, 1].set_title('Jahrmarkt')\n",
-    "_ = axs[1, 1].imshow(low_pass(img_jahrmarkt, 10), cmap = 'gray')\n",
+    "_ = axs[1, 1].imshow(low_pass(img_jahrmarkt, 5000000), cmap = 'gray')\n",
     "_ = axs[1, 1].set_title('Jahrmarkt Low Pass')"
    ]
   },
@@ -171,7 +173,7 @@
    "source": [
     "### Hinweise:\n",
     "\n",
-    "* Für die inverse Fourier-Transformation nutzen Sie die OpenCV Funktion [dft](https://docs.opencv.org/3.4/d2/de8/group__core__array.html#gadd6cf9baf2b8b704a11b5f04aaf4f39d)"
+    "* Für die inverse Fourier-Transformation nutzen Sie die OpenCV Funktion [dft](https://docs.opencv.org/3.4/d2/de8/group__core__array.html#gadd6cf9baf2b8b704a11b5f04aaf4f39d) oder [idft](https://docs.opencv.org/3.4/d2/de8/group__core__array.html#gaa708aa2d2e57a508f968eb0f69aa5ff1)"
    ]
   },
   {