auto downsample large image

jia-kai · jia-kai · commit 98dd82c579e6 · 2013-05-16T15:00:20.000+08:00
diff --git a/facepp.py b/facepp.py
@@ -1,6 +1,6 @@
 # -*- coding: utf-8 -*-
 # $File: facepp.py
-# $Date: Fri Apr 05 17:29:44 2013 +0800
+# $Date: Thu May 16 14:59:36 2013 +0800
 # $Author: jiakai@megvii.com
 #
 # This program is free software. It comes without any warranty, to
@@ -39,25 +39,71 @@
 import urllib2
 import json
 import os
+import os.path
 import itertools
 import mimetools
 import mimetypes
 import time
+import tempfile
 from collections import Iterable
 from cStringIO import StringIO
 
 class File(object):
     """an object representing a local file"""
     path = None
+    content = None
     def __init__(self, path):
         self.path = path
-
-    def get_content(self):
-        with open(self.path, 'rb') as f:
-            return f.read()
+        self._get_content()
+
+    def _resize_cv2(self, ftmp):
+        try:
+            import cv2
+        except ImportError:
+            return False
+        img = cv2.imread(self.path)
+        assert img is not None and img.size != 0, 'Invalid image'
+        bigdim = max(img.shape[0], img.shape[1])
+        downscale = max(1., bigdim / 600.)
+        img = cv2.resize(img,
+                (int(img.shape[1] / downscale),
+                    int(img.shape[0] / downscale)))
+        cv2.imwrite(ftmp, img)
+        return True
+
+    def _resize_PIL(self, ftmp):
+        try:
+            import PIL.Image
+        except ImportError:
+            return False
+
+        img = PIL.Image.open(self.path)
+        bigdim = max(img.size[0], img.size[1])
+        downscale = max(1., bigdim / 600.)
+        img = img.resize(
+                (int(img.size[0] / downscale), int(img.size[1] / downscale)))
+        img.save(ftmp)
+        return True
+
+    def _get_content(self):
+        """read image content; resize the image if necessary"""
+
+        if os.path.getsize(self.path) > 2 * 1024 * 1024:
+            ftmp = tempfile.NamedTemporaryFile(
+                    suffix = '.jpg', delete = False).name
+            try:
+                if not (self._resize_cv2(ftmp) or self._resize_PIL(ftmp)):
+                    raise APIError(-1, None, 'image file size too large')
+                with open(ftmp, 'rb') as f:
+                    self.content = f.read()
+            finally:
+                os.unlink(ftmp)
+        else:
+            with open(self.path, 'rb') as f:
+                self.content = f.read()
 
     def get_filename(self):
-        return self.path
+        return os.path.basename(self.path)
 
 
 class APIError(Exception):
@@ -162,7 +208,7 @@ def __call__(self, post = False, *args, **kargs):
         for (k, v) in kargs.iteritems():
             if isinstance(v, File):
                 add_form = True
-                form.add_file(k, v.get_filename(), v.get_content())
+                form.add_file(k, v.get_filename(), v.content)
 
         if post:
             url = self._urlbase
