Merge pull request #21 from photoshell/support_thumbnails

Support thumbnails and update API

README.md

@@ -8,6 +8,5 @@
 from rawkit.raw import Raw
 
 with Raw(filename='some/raw/image.CR2') as raw:
-	raw.process()
 	raw.save(filename='some/destination/image.ppm')
 ```

rawkit/raw.py

@@ -18,7 +18,6 @@ class Raw(object):
         from rawkit.raw import Raw
 
         with Raw(filename='some/raw/image.CR2') as raw:
-            raw.process()
             raw.save(filename='some/destination/image.ppm')
 
     :param filename: the name of a raw file to load
@@ -32,6 +31,11 @@ def __init__(self, filename=None):
         self.data = libraw.libraw_init(0)
         libraw.libraw_open_file(self.data, filename.encode('ascii'))
 
+        self.options = {}
+
+        self.image_unpacked = False
+        self.thumb_unpacked = False
+
     def __enter__(self):
         """Return a Raw object for use in context managers."""
         return self
@@ -44,20 +48,25 @@ def close(self):
         """Free the underlying raw representation."""
         libraw.libraw_close(self.data)
 
-    def process(self, options=None):
-        """
-        Unpack and process the raw data into something more usable.
+    def unpack(self):
+        """Unpack and the raw data."""
+        if not self.image_unpacked:
+            libraw.libraw_unpack(self.data)
+            self.image_unpacked = True
 
-        """
+    def unpack_thumb(self):
+        """Unpack the thumbnail data."""
+        if not self.thumb_unpacked:
+            libraw.libraw_unpack_thumb(self.data)
+            self.thumb_unpacked = True
 
-        libraw.libraw_unpack(self.data)
+    def process(self):
+        """Process the raw data based on self.options"""
         libraw.libraw_dcraw_process(self.data)
 
     def save(self, filename=None, filetype='ppm'):
         """
-        Save the image data as a new PPM or TIFF image. This method is provided
-        for convenience, but in general export should actually be handled by
-        another library (such as Wand).
+        Save the image data as a new PPM or TIFF image.
 
         Keyword arguments:
         filename -- A filename to save.
@@ -66,11 +75,29 @@ def save(self, filename=None, filetype='ppm'):
         assert filetype in ('ppm', 'tiff')
         self.data.contents.params.output_tiff = 0 if filetype is 'ppm' else 1
 
+        self.unpack()
+        self.process()
+
         libraw.libraw_dcraw_ppm_tiff_writer(
             self.data, filename.encode('ascii'))
 
+    def save_thumb(self, filename=None):
+        """
+        Save the thumbnail data.
+
+        Keyword arguments:
+        filename -- A filename to save.
+        """
+        self.unpack_thumb()
+
+        libraw.libraw_dcraw_thumb_writer(
+            self.data, filename.encode('ascii'))
+
     def to_buffer(self):
         """Return the image data as an RGB buffer."""
+        self.unpack()
+        self.process()
+
         processed_image = libraw.libraw_dcraw_make_mem_image(self.data)
         data_pointer = ctypes.cast(
             processed_image.contents.data,
@@ -80,3 +107,17 @@ def to_buffer(self):
         libraw.libraw_dcraw_clear_mem(processed_image)
 
         return data
+
+    def thumbnail_to_buffer(self):
+        """Return the thumbnail data as an RGB buffer."""
+        self.unpack_thumb()
+
+        processed_image = libraw.libraw_dcraw_make_mem_thumb(self.data)
+        data_pointer = ctypes.cast(
+            processed_image.contents.data,
+            ctypes.POINTER(ctypes.c_byte * processed_image.contents.data_size)
+        )
+        data = bytearray(data_pointer.contents)
+        libraw.libraw_dcraw_clear_mem(processed_image)
+
+        return data

tests/unit/raw_test.py

@@ -19,55 +19,78 @@ def output_file():
     return 'potato_salad.out'
 
 
-def test_create(mock_libraw, input_file):
-    with Raw(filename=input_file) as raw:
-        mock_libraw.libraw_init.assert_called_once()
-        mock_libraw.libraw_open_file.assert_called_once_with(
-            raw.data,
-            input_file.encode('ascii'),
-        )
+@pytest.yield_fixture
+def raw(mock_libraw, input_file):
+    with Raw(filename=input_file) as raw_obj:
+        yield raw_obj
+    mock_libraw.libraw_close.assert_called_once_with(raw_obj.data)
+
+
+def test_create(mock_libraw, raw, input_file):
+    mock_libraw.libraw_init.assert_called_once()
+    mock_libraw.libraw_open_file.assert_called_once_with(
+        raw.data,
+        input_file.encode('ascii'),
+    )
 
-    mock_libraw.libraw_close.assert_called_once_with(raw.data)
 
+def test_unpack(mock_libraw, raw):
+    raw.unpack()
+    mock_libraw.libraw_unpack.assert_called_once_with(raw.data)
 
-def test_process(mock_libraw, input_file):
-    with Raw(filename=input_file) as raw:
-        raw.process()
 
+def test_unpack_twice(mock_libraw, raw):
+    raw.unpack()
+    raw.unpack()
     mock_libraw.libraw_unpack.assert_called_once_with(raw.data)
-    mock_libraw.libraw_dcraw_process.assert_called_once_with(raw.data)
 
 
-def _test_save(mock_libraw, input_file, output_file, filetype):
-    with Raw(filename=input_file) as raw:
-        raw.process()
-        raw.save(filename=output_file, filetype=filetype)
+def test_unpack_thumb(mock_libraw, raw):
+    raw.unpack_thumb()
+    mock_libraw.libraw_unpack_thumb.assert_called_once_with(raw.data)
+
+
+def test_unpack_thumb_twice(mock_libraw, raw):
+    raw.unpack_thumb()
+    raw.unpack_thumb()
+    mock_libraw.libraw_unpack_thumb.assert_called_once_with(raw.data)
+
+
+def _test_save(mock_libraw, raw, output_file, filetype):
+    raw.save(filename=output_file, filetype=filetype)
 
     mock_libraw.libraw_dcraw_ppm_tiff_writer.assert_called_once_with(
         raw.data,
         output_file.encode('ascii'),
     )
 
 
-def test_save_ppm(mock_libraw, input_file, output_file):
-    _test_save(mock_libraw, input_file, output_file, 'ppm')
+def test_save_ppm(mock_libraw, raw, output_file):
+    _test_save(mock_libraw, raw, output_file, 'ppm')
 
 
-def test_save_tiff(mock_libraw, input_file, output_file):
-    _test_save(mock_libraw, input_file, output_file, 'tiff')
+def test_save_tiff(mock_libraw, raw, output_file):
+    _test_save(mock_libraw, raw, output_file, 'tiff')
 
 
-def test_save_invalid(mock_libraw, input_file, output_file):
+def test_save_invalid(mock_libraw, raw, output_file):
     with pytest.raises(AssertionError):
-        _test_save(mock_libraw, input_file, output_file, 'jpg')
+        _test_save(mock_libraw, raw, output_file, 'jpg')
+
+
+def test_save_thumb(mock_libraw, raw, output_file):
+    raw.save_thumb(filename=output_file)
 
+    mock_libraw.libraw_dcraw_thumb_writer.assert_called_once_with(
+        raw.data,
+        output_file.encode('ascii'),
+    )
 
-def test_to_buffer(mock_libraw, input_file):
-    with Raw(filename=input_file) as raw:
-        raw.process()
-        # Quick hack because to_buffer does some ctypes acrobatics
-        with mock.patch('rawkit.raw.ctypes'):
-            raw.to_buffer()
+
+def test_to_buffer(mock_libraw, raw):
+    # Quick hack because to_buffer does some ctypes acrobatics
+    with mock.patch('rawkit.raw.ctypes'):
+        raw.to_buffer()
 
     mock_libraw.libraw_dcraw_make_mem_image.assert_called_once_with(
         raw.data,
@@ -76,3 +99,17 @@ def test_to_buffer(mock_libraw, input_file):
     mock_libraw.libraw_dcraw_clear_mem.assert_called_once_with(
         mock_libraw.libraw_dcraw_make_mem_image(raw.data),
     )
+
+
+def test_thumbnail_to_buffer(mock_libraw, raw):
+    # Quick hack because thumbnail_to_buffer does some ctypes acrobatics
+    with mock.patch('rawkit.raw.ctypes'):
+        raw.thumbnail_to_buffer()
+
+    mock_libraw.libraw_dcraw_make_mem_thumb.assert_called_once_with(
+        raw.data,
+    )
+
+    mock_libraw.libraw_dcraw_clear_mem.assert_called_once_with(
+        mock_libraw.libraw_dcraw_make_mem_thumb(raw.data),
+    )