more explanation

tha_colab.ipynb

@@ -5,12 +5,28 @@
    "id": "color-singer",
    "metadata": {},
    "source": [
+    "# Talking Head Anime from a Single Image (Manual Poser Tool)\n",
+    "\n",
     "**Instruction**\n",
     "\n",
     "1. From the main menu, click \"Runtime > Change runtime type.\" \n",
     "2. Change \"Hardware accelerator\" to \"GPU,\" and click \"Save.\"\n",
     "3. Run the four cells below, one by one, in order by clicking the \"Play\" button to the left of it. Wait for each cell to finish before going to the next one.\n",
-    "4. Scroll down to the end of the last cell, and play with the GUI."
+    "4. Scroll down to the end of the last cell, and play with the GUI.\n",
+    "\n",
+    "**Constraints on Images**\n",
+    "\n",
+    "1. Must be an image of a single humanoid anime character.\n",
+    "2. Must be of size 256x256.\n",
+    "3. The head must be roughly contained in the middle 128x128 middle box.\n",
+    "4. Must have PNG format.\n",
+    "5. Must have an alpha channel.\n",
+    "6. Background pixels must have RGBA=(0,0,0,0). See [this link](https://github.com/pkhungurn/talking-head-anime-demo/issues/1) if you do not get clean results.\n",
+    "\n",
+    "**Links**\n",
+    "\n",
+    "* Github repository: http://github.com/pkhungurn/talking-head-anime-demo\n",
+    "* Project writeup: http://pkhungurn.github.io/talking-head-anime"
    ]
   },
   {