diff --git a/assignments/04_assignment.ipynb b/assignments/04_assignment.ipynb
index 28c4017..7a86cb7 100644
--- a/assignments/04_assignment.ipynb
+++ b/assignments/04_assignment.ipynb
@@ -17,7 +17,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 1,
+   "execution_count": null,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -27,7 +27,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 2,
+   "execution_count": null,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -58,17 +58,26 @@
     "\n",
     "Qualify the noise and sharpness in the images. Make a plot images, noise\n",
     "\n",
-    "Please download sample picture from [here](http://www.imageprocessingplace.com/downloads_V3/root_downloads/image_databases/standard_test_images.zip)"
+    "Please download sample picture from [here](http://sipi.usc.edu/database/misc.zip)"
    ]
   },
   {
    "cell_type": "code",
-   "execution_count": 8,
+   "execution_count": null,
    "metadata": {},
    "outputs": [],
    "source": [
     "# Load the pictures here\n",
-    "sample_images = None"
+    "sample_images = []\n",
+    "direc = 'misc/' # directory of the sample pictures realtivly to your notebook\n",
+    "for number in [1,3,5,6]:\n",
+    "    sample_images.append(\n",
+    "        np.array(Image.open(direc+'4.2.0'+str(number)+'.tiff'))\n",
+    "    )\n",
+    "for name in ['house', 'ruler.512']:\n",
+    "    sample_images.append(\n",
+    "        np.array(Image.open(direc+name+'.tiff'))\n",
+    "    )"
    ]
   },
   {
@@ -117,15 +126,13 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "metadata": {
-    "collapsed": true
-   },
+   "metadata": {},
    "outputs": [],
    "source": [
     "def jpeg_enocde(img, quality):\n",
     "    pil_img = Image.fromarray(img)\n",
     "    buffer = BytesIO()\n",
-    "    im1.save(buffer, \"JPEG\", quality=quality)\n",
+    "    pil_img.save(buffer, \"JPEG\", quality=quality)\n",
     "    return buffer\n",
     "\n",
     "def jpeg_decode(buffer):\n",
@@ -137,15 +144,6 @@
     "    return jpeg_decode(as_jpeg)"
    ]
   },
-  {
-   "cell_type": "code",
-   "execution_count": null,
-   "metadata": {},
-   "outputs": [],
-   "source": [
-    "len(images_for_jpeg)"
-   ]
-  },
   {
    "cell_type": "code",
    "execution_count": null,
@@ -169,7 +167,7 @@
     "    # your code\n",
     "    return random.randint(0, 10)\n",
     "\n",
-    "for i, img in enumerate(images_for_jpeg):\n",
+    "for i, img in enumerate(sample_images):\n",
     "    print(i)\n",
     "    compressed_images = [images10[i], images50[i], images80[i]]\n",
     "    plt.bar(range(len(compressed_images)),\n",
@@ -180,9 +178,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "metadata": {
-    "collapsed": true
-   },
+   "metadata": {},
    "outputs": [],
    "source": []
   }