Scripted pretrained model download (#24)

* Script to download models

* Model download bash script, usage explained

USAGE.md

@@ -39,9 +39,14 @@ These models are extracted from Torch7 models and currently used in the project.
 
 **Original Torch7 models**
 
+Manually download the model files.
 - Download pretrained networks via the following [link](https://drive.google.com/open?id=1ENgQm9TgabE1R99zhNf5q6meBvX6WFuq).
 - Unzip and store the model files under `models`.
 
+Automatically downloads pretrained networks and unzips them.
+- Requires requests (`pip install requests`)
+- `bash download_models.sh`
+
 `converter.py` shows how to convert Torch7 models to PyTorch models.
 
 ### Example 1: Transfer the style of a style photo to a content photo.

download_models.py

@@ -0,0 +1,35 @@
+# Download code taken from Code taken from https://stackoverflow.com/questions/25010369/wget-curl-large-file-from-google-drive/39225039#39225039
+import requests
+
+def download_file_from_google_drive(id, destination):
+    URL = "https://docs.google.com/uc?export=download"
+
+    session = requests.Session()
+
+    response = session.get(URL, params = { 'id' : id }, stream = True)
+    token = get_confirm_token(response)
+
+    if token:
+        params = { 'id' : id, 'confirm' : token }
+        response = session.get(URL, params = params, stream = True)
+
+    save_response_content(response, destination)    
+
+def get_confirm_token(response):
+    for key, value in response.cookies.items():
+        if key.startswith('download_warning'):
+            return value
+
+    return None
+
+def save_response_content(response, destination):
+    CHUNK_SIZE = 32768
+
+    with open(destination, "wb") as f:
+        for chunk in response.iter_content(CHUNK_SIZE):
+            if chunk: # filter out keep-alive new chunks
+                f.write(chunk)
+
+file_id = '1ENgQm9TgabE1R99zhNf5q6meBvX6WFuq'
+destination = './models.zip'
+download_file_from_google_drive(file_id, destination)

download_models.sh

@@ -0,0 +1,3 @@
+#!/bin/bash
+python download_models.py
+unzip models.zip