Object with pre-creation of the needed structures and memory allocation.

svartalf · svartalf · commit 263854e6e946 · 2012-05-24T17:25:55.000+09:00
Useful for streaming recognition, but still in development
diff --git a/quirc/__init__.py b/quirc/__init__.py
@@ -6,4 +6,4 @@
 __version__ = '0.6.2'
 
 import api
-from base import decode
+from base import decode, Decoder
diff --git a/quirc/base.py b/quirc/base.py
@@ -2,16 +2,15 @@
 
 import ctypes
 
-from quirc import api
+import api
+import compat
+import converters
 
-USING_PIL = True
-try:
-    from PIL import Image
-except ImportError:
+if compat.have_pil:
     try:
         import Image
     except ImportError:
-        USING_PIL = False
+        from PIL import Image
 
 
 def decode(image):
@@ -34,24 +33,16 @@ def decode(image):
     buffer = api.begin(obj, width, height)
 
     # Fill buffer with a image pixels. One cell, one pixel.
-    # TODO: looks like a very slow operation
-    idx = 0
-    for i in range(width):
-        for j in range(height):
-            buffer[idx] = ctypes.c_uint8(pixels[j, i])
-            idx += 1
-
-    del idx
+    for idx, pixel in enumerate(converters.pil(image)):
+        buffer[idx] = pixel
 
     # Finish codes identification
     api.end(obj)
 
-    num_codes = api.count(obj)
-
     code = api.structures.Code()
     data = api.structures.Data()
 
-    for i in range(num_codes):
+    for i in range(api.count(obj)):
 
         # Extract first code
         api.extract(obj, i, code)
@@ -67,3 +58,37 @@ def decode(image):
         }
 
     api.destroy(obj)
+
+
+class Decoder(object):
+
+    def __init__(self, width, height):
+        self._width = width
+        self._height = height
+
+        self._obj = api.new()
+        api.resize(self._obj, self._width, self._height)
+
+        self._code = api.structures.Code()
+        self._data = api.structures.Data()
+
+    def decode(self, image):
+        buffer = api.begin(self._obj, self._width, self._height)
+
+        if image.mode not in ('1', 'L'):
+            image = image.convert('L')
+        pixels = image.load()
+
+        idx = 0
+        for i in range(self._width):
+            for j in range(self._height):
+                buffer[idx] = ctypes.c_uint8(pixels[j, i])
+                idx += 1
+
+        del idx
+
+        # Finish codes identification
+        api.end(self._obj)
+
+    def __del__(self):
+        api.destroy(self._obj)
diff --git a/quirc/compat.py b/quirc/compat.py
@@ -0,0 +1,13 @@
+# -*- coding: utf-8 -*-
+
+"""Miscellaneous compatibility checks"""
+
+# Image libraries
+have_pil = True
+try:
+    from PIL import Image
+except ImportError:
+    try:
+        import Image
+    except ImportError:
+        have_pil = False
diff --git a/quirc/converters.py b/quirc/converters.py
@@ -0,0 +1,25 @@
+# -*- coding: utf-8 -*-
+
+"""Converters from the external libraries image objects to the internal format
+
+Handles convertion into a grayscale mode internally.
+"""
+
+import ctypes
+
+def pil(image):
+    """Convert the PIL.Image object to the pixels buffer
+
+    Parameters::
+        image : PIL.Image object
+    """
+
+    if image.mode not in ('1', 'L'):
+        image = image.convert('L')
+    width, height = image.size
+
+    pixels = image.load()
+
+    for i in range(width):
+        for j in range(height):
+            yield ctypes.c_uint8(pixels[j, i])
diff --git a/tests/test_quirc.py b/tests/test_quirc.py
@@ -7,24 +7,31 @@
     import unittest
 
 import quirc
+from quirc import compat
 
-USING_PIL = True
-try:
-    import Image
-except ImportError:
+if compat.have_pil:
     try:
-        from PIL import Image
+        import Image
     except ImportError:
-        USING_PIL = False
+        from PIL import Image
 
 
 class TestQuircCase(unittest.TestCase):
 
     def setUp(self):
         self._folder = os.path.abspath(os.path.dirname(__file__))
 
-    @unittest.skipIf(not USING_PIL, 'PIL is unaccessible')
+    def test_decoder(self):
+        decoder = quirc.Decoder(148, 148)
+        decoder.decode(Image.open(os.path.join(self._folder, 'images', 'link.gif')))
+
+    @unittest.skipIf(not compat.have_pil, 'PIL is unaccessible')
     def test_pil(self):
+        try:
+            import Image
+        except ImportError:
+            from PIL import Image
+
         image = Image.open(os.path.join(self._folder, 'images', 'link.gif'))
 
         result = list(quirc.decode(image))
