From b6f2125e71ff6ba288c8d887cb6b1a1c9b7ec846 Mon Sep 17 00:00:00 2001 From: Juan Nunez-Iglesias Date: Tue, 31 Mar 2015 00:24:23 +1100 Subject: [PATCH] Allow keyword arguments to imsave for PIL plugin Certain formats allow additional arguments, such as `compress=` for TIFF or `quality=` for JPEG. Without this patch, the plugin simply does not allow these arguments to be passed. --- skimage/io/_plugins/pil_plugin.py | 12 +++++++--- skimage/io/tests/test_pil.py | 37 ++++++++++++++++++++++++------- 2 files changed, 38 insertions(+), 11 deletions(-) diff --git a/skimage/io/_plugins/pil_plugin.py b/skimage/io/_plugins/pil_plugin.py index ae74ff7b..2e45cfd7 100644 --- a/skimage/io/_plugins/pil_plugin.py +++ b/skimage/io/_plugins/pil_plugin.py @@ -196,7 +196,7 @@ def ndarray_to_pil(arr, format_str=None): return im -def imsave(fname, arr, format_str=None): +def imsave(fname, arr, format_str=None, **kwargs): """Save an image to disk. Parameters @@ -210,6 +210,12 @@ def imsave(fname, arr, format_str=None): format_str: str Format to save as, this is defaulted to PNG if using a file-like object; this will be derived from the extension if fname is a string + kwargs: dict + Keyword arguments to the Pillow save function (or tifffile save + function, for Tiff files). These are format dependent. For example, + Pillow's JPEG save function supports an integer ``quality`` argument + with values in [1, 95], while TIFFFile supports a ``compress`` + integer argument with values in [0, 9]. Notes ----- @@ -251,7 +257,7 @@ def imsave(fname, arr, format_str=None): use_tif = True if use_tif: - tif_imsave(fname, arr) + tif_imsave(fname, arr, **kwargs) return if arr.ndim not in (2, 3): @@ -262,4 +268,4 @@ def imsave(fname, arr, format_str=None): raise ValueError("Invalid number of channels in image array.") img = ndarray_to_pil(arr, format_str=format_str) - img.save(fname, format=format_str) + img.save(fname, format=format_str, **kwargs) diff --git a/skimage/io/tests/test_pil.py b/skimage/io/tests/test_pil.py index e8909503..fcff1907 100644 --- a/skimage/io/tests/test_pil.py +++ b/skimage/io/tests/test_pil.py @@ -97,6 +97,17 @@ def test_imread_truncated_jpg(): os.path.join(data_dir, 'truncated.jpg')) +def test_jpg_quality_arg(): + chessboard = np.load(os.path.join(data_dir, 'chessboard_GRAY_U8.npy')) + with NamedTemporaryFile(suffix='.jpg') as jpg: + fname = jpg.name + imsave(fname, chessboard, quality=95) + im = imread(fname) + sim = ssim(chessboard, im, + dynamic_range=chessboard.max() - chessboard.min()) + assert sim > 0.99 + + def test_imread_uint16_big_endian(): expected = np.load(os.path.join(data_dir, 'chessboard_GRAY_U8.npy')) img = imread(os.path.join(data_dir, 'chessboard_GRAY_U16B.tif')) @@ -214,11 +225,19 @@ def test_cmyk(): class TestSaveTIF: - def roundtrip(self, dtype, x): + def roundtrip(self, dtype, x, compress): f = NamedTemporaryFile(suffix='.tif') fname = f.name f.close() - imsave(fname, x) + if dtype == np.bool: + expected = ['low contrast'] + else: + expected = [] + with expected_warnings(expected): + if compress > 0: + imsave(fname, x, compress=compress) + else: + imsave(fname, x) y = imread(fname) assert_array_equal(x, y) @@ -226,13 +245,15 @@ class TestSaveTIF: for shape in [(10, 10), (10, 10, 3), (10, 10, 4)]: for dtype in (np.uint8, np.uint16, np.int16, np.float32, np.float64, np.bool): - x = np.random.rand(*shape) + for compress in [0, 2]: + x = np.random.rand(*shape) - if not np.issubdtype(dtype, float) and not dtype == np.bool: - x = (x * np.iinfo(dtype).max).astype(dtype) - else: - x = x.astype(dtype) - yield self.roundtrip, dtype, x + if not np.issubdtype(dtype, float) and \ + not dtype == np.bool: + x = (x * np.iinfo(dtype).max).astype(dtype) + else: + x = x.astype(dtype) + yield self.roundtrip, dtype, x, compress if __name__ == "__main__": run_module_suite()