ReaderChain and image reader

3 files changed, 134 insertions, 0 deletions

diff --git a/bsie/reader/image/__init__.py b/bsie/reader/image/__init__.py
new file mode 100644
index 0000000..85dad85
--- /dev/null
+++ b/bsie/reader/image/__init__.py
@@ -0,0 +1,36 @@
+"""
+
+Part of the bsie module.
+A copy of the license is provided with the project.
+Author: Matthias Baumgartner, 2022
+"""
+# standard imports
+import typing
+
+# external imports
+import PIL.Image
+
+# inner-module imports
+from .. import chain
+
+# constants
+_FILE_FORMAT_READERS: typing.Sequence[str] = (
+    __package__ + '._raw.RawImage',
+    __package__ + '._pillow.PillowImage',
+    )
+
+# exports
+__all__: typing.Sequence[str] = (
+    'Image',
+    )
+
+
+## code ##
+
+class Image(chain.ReaderChain[PIL.Image]): # pylint: disable=too-few-public-methods
+    """Read an image file."""
+
+    def __init__(self, cfg):
+        super().__init__(_FILE_FORMAT_READERS, cfg)
+
+## EOF ##
diff --git a/bsie/reader/image/_pillow.py b/bsie/reader/image/_pillow.py
new file mode 100644
index 0000000..ee0662d
--- /dev/null
+++ b/bsie/reader/image/_pillow.py
@@ -0,0 +1,37 @@
+"""
+
+Part of the bsie module.
+A copy of the license is provided with the project.
+Author: Matthias Baumgartner, 2022
+"""
+# standard imports
+import typing
+
+# external imports
+import PIL.Image
+
+# bsie imports
+from bsie.utils import errors
+
+# inner-module imports
+from .. import base
+
+# exports
+__all__: typing.Sequence[str] = (
+    'PillowImage',
+    )
+
+
+## code ##
+
+class PillowImage(base.Reader):
+    """Use PIL to read content of a variety of image file types."""
+
+    def __call__(self, path: str) -> PIL.Image:
+        try:
+            # open file with PIL
+            return PIL.Image.open(path)
+        except IOError as err:
+            raise errors.ReaderError(path) from err
+
+# EOF ##
diff --git a/bsie/reader/image/_raw.py b/bsie/reader/image/_raw.py
new file mode 100644
index 0000000..77be357
--- /dev/null
+++ b/bsie/reader/image/_raw.py
@@ -0,0 +1,61 @@
+"""
+
+Part of the bsie module.
+A copy of the license is provided with the project.
+Author: Matthias Baumgartner, 2022
+"""
+# standard imports
+import typing
+
+# external imports
+import PIL.Image
+import rawpy
+
+# bsie imports
+from bsie.utils import errors, filematcher
+
+# inner-module imports
+from .. import base
+
+# constants
+MATCH_RULE = 'mime={image/x-nikon-nef} | extension={nef}'
+
+# exports
+__all__: typing.Sequence[str] = (
+    'RawImage',
+    )
+
+
+## code ##
+
+class RawImage(base.Reader):
+    """Use rawpy to read content of raw image file types."""
+
+    # file matcher
+    match: filematcher.Matcher
+
+    # additional kwargs to rawpy's postprocess
+    rawpy_kwargs: typing.Dict[str, typing.Any]
+
+    def __init__(self, **rawpy_kwargs):
+        match_rule = rawpy_kwargs.pop('file_match_rule', MATCH_RULE)
+        self._match = filematcher.parse(match_rule)
+        self._rawpy_kwargs = rawpy_kwargs
+
+    def __call__(self, path: str) -> PIL.Image:
+        # perform quick checks first
+        if not self._match(path):
+            raise errors.ReaderError(path)
+
+        try:
+            # open file with rawpy
+            ary = rawpy.imread(path).postprocess(**self._rawpy_kwargs)
+            # convert to PIL.Image
+            return PIL.Image.fromarray(ary)
+        except (rawpy.LibRawFatalError, # pylint: disable=no-member # pylint doesn't find the errors
+                rawpy.NotSupportedError, # pylint: disable=no-member
+                rawpy.LibRawNonFatalError, # pylint: disable=no-member
+               ) as err:
+            raise errors.ReaderError(path) from err
+
+## EOF ##