def _read_fit_image(path: Path):
"""
read FIT image from filesystem
:param path: path to image file to load from
:type path: pathlib.Path
:return: the loaded image, with data and headers parsed or None if a known error occurred
:rtype: Image or None
"""
try:
with fits.open(str(path.resolve())) as fit:
# pylint: disable=E1101
data = fit[0].data
header = fit[0].header
image = Image(data)
if 'BAYERPAT' in header:
image.bayer_pattern = header['BAYERPAT']
_set_image_file_origin(image, path)
except OSError as error:
_report_fs_error(path, error)
return None
return image
def _read_raw_image(path: Path):
"""
Reads a RAW DLSR image from file
:param path: path to the file to read from
:type path: pathlib.Path
:return: the image or None if a known error occurred
:rtype: Image or None
"""
try:
with imread(str(path.resolve())) as raw_image:
# in here, we make sure we store the bayer pattern as it would be advertised if image was a FITS image.
#
# lets assume image comes from a DSLR sensor with the most common bayer pattern.
#
# The actual/physical bayer pattern would look like a repetition of :
#
# +---+---+
# | R | G |
# +---+---+
# | G | B |
# +---+---+
#
# RawPy will report the bayer pattern description as 2 discrete values :
#
# 1) raw_image.raw_pattern : a 2x2 numpy array representing the indices used to express the bayer patten
#
# in our example, its value is :
#
# +---+---+
# | 0 | 1 |
# +---+---+
# | 3 | 2 |
# +---+---+
#
# and its flatten version is :
#
# [0, 1, 3, 2]
#
# 2) raw_image.color_desc : a bytes literal formed of the color of each pixel of the bayer pattern, in
# ascending index order from raw_image.raw_pattern
#
# in our example, its value is : b'RGBG'
#
# We need to express/store this pattern in a more common way, i.e. as it would be described in a FITS
# header. Or put simply, we want to express the bayer pattern as it would be described if
# raw_image.raw_pattern was :
#
# +---+---+
# | 0 | 1 |
# +---+---+
# | 2 | 3 |
# +---+---+
bayer_pattern_indices = raw_image.raw_pattern.flatten()
bayer_pattern_desc = raw_image.color_desc.decode()
_LOGGER.debug(f"Bayer pattern indices = {bayer_pattern_indices}")
_LOGGER.debug(f"Bayer pattern description = {bayer_pattern_desc}")
assert len(bayer_pattern_indices) == len(bayer_pattern_desc)
bayer_pattern = ""
for i, index in enumerate(bayer_pattern_indices):
assert bayer_pattern_indices[i] < len(bayer_pattern_indices)
bayer_pattern += bayer_pattern_desc[index]
_LOGGER.debug(
f"Computed, FITS-compatible bayer pattern = {bayer_pattern}")
new_image = Image(raw_image.raw_image_visible.copy())
new_image.bayer_pattern = bayer_pattern
_set_image_file_origin(new_image, path)
return new_image
except LibRawNonFatalError as non_fatal_error:
_report_fs_error(path, non_fatal_error)
return None
except LibRawFatalError as fatal_error:
_report_fs_error(path, fatal_error)
return None