def _prepared_data_and_metadata(hdr_file, image, **kwargs):
'''
Return data array and metadata dict representing `image`.
'''
import os
import sys
import spectral
from spectral.io.spyfile import SpyFile, interleave_transpose
endian_out = str(kwargs.get('byteorder', sys.byteorder)).lower()
if endian_out in ('0', 'little'):
endian_out = 'little'
elif endian_out in ('1', 'big'):
endian_out = 'big'
else:
raise ValueError('Invalid byte order: "%s".' % endian_out)
if isinstance(image, np.ndarray):
data = image
src_interleave = 'bip'
swap = False
elif isinstance(image, SpyFile):
if image.using_memmap is True:
data = image._memmap
src_interleave = {spectral.BSQ: 'bsq', spectral.BIL: 'bil',
spectral.BIP: 'bip'}[image.interleave]
swap = image.swap
else:
data = image.load(dtype=image.dtype, scale=False)
src_interleave = 'bip'
swap = False
else:
data = image.load()
src_interleave = 'bip'
swap = False
metadata = kwargs.get('metadata', {}).copy()
add_image_info_to_metadata(image, metadata)
if hasattr(image, 'bands'):
add_band_info_to_metadata(image.bands, metadata)
dtype = np.dtype(kwargs.get('dtype', data.dtype)).char
_validate_dtype(dtype)
if dtype != data.dtype.char:
data = data.astype(dtype)
metadata['data type'] = dtype_to_envi[dtype]
interleave = kwargs.get('interleave', 'bip').lower()
if interleave not in ['bil', 'bip', 'bsq']:
raise ValueError('Invalid interleave: %s'
% str(kwargs['interleave']))
if interleave != src_interleave:
data = data.transpose(interleave_transpose(src_interleave, interleave))
metadata['interleave'] = interleave
metadata['byte order'] = 1 if endian_out == 'big' else 0
if (endian_out == sys.byteorder and not data.dtype.isnative) or \
(endian_out != sys.byteorder and data.dtype.isnative):
data = data.byteswap()
return data, metadata
def save_image(hdr_file, image, **kwargs):
'''
Saves an image to disk.
Arguments:
`hdr_file` (str):
Header file (with ".hdr" extension) name with path.
`image` (SpyFile object or numpy.ndarray):
The image to save.
Keyword Arguments:
`dtype` (numpy dtype or type string):
The numpy data type with which to store the image. For example,
to store the image in 16-bit unsigned integer format, the argument
could be any of `numpy.uint16`, "u2", "uint16", or "H".
`force` (bool):
If the associated image file or header already exist and `force` is
True, the files will be overwritten; otherwise, if either of the
files exist, an exception will be raised.
`ext` (str):
The extension to use for the image file. If not specified, the
default extension ".img" will be used. If `ext` is an empty
string, the image file will have the same name as the header but
without the ".hdr" extension.
`interleave` (str):
The band interleave format to use in the file. This argument
should be one of "bil", "bip", or "bsq". If not specified, the
image will be written in BIP interleave.
`byteorder` (int or string):
Specifies the byte order (endian-ness) of the data as
written to disk. For little endian, this value should be
either 0 or "little". For big endian, it should be
either 1 or "big". If not specified, native byte order
will be used.
`metadata` (dict):
A dict containing ENVI header parameters (e.g., parameters
extracted from a source image).
Example::
>>> # Save the first 10 principal components of an image
>>> data = open_image('92AV3C.lan').load()
>>> pc = principal_components(data)
>>> pcdata = pc.reduce(num=10).transform(data)
>>> envi.save_image('pcimage.hdr', pcdata, dtype=np.float32)
If the source image being saved was already in ENVI format, then the
SpyFile object for that image will contain a `metadata` dict that can be
passed as the `metadata` keyword. However, care should be taken to ensure
that all the metadata fields from the source image are still accurate
(e.g., band names or wavelengths will no longer be correct if the data
being saved are from a principal components transformation).
'''
import os
import sys
import __builtin__
import spectral
from spectral.io.spyfile import SpyFile, interleave_transpose
metadata = kwargs.get('metadata', {}).copy()
force = kwargs.get('force', False)
img_ext = kwargs.get('ext', '.img')
endian_out = str(kwargs.get('byteorder', sys.byteorder)).lower()
if endian_out in ('0', 'little'):
endian_out = 'little'
elif endian_out in ('1', 'big'):
endian_out = 'big'
else:
raise ValueError('Invalid byte order: "%s".' % endian_out)
(hdr_file, img_file) = check_new_filename(hdr_file, img_ext, force)
if isinstance(image, np.ndarray):
data = image
src_interleave = 'bip'
swap = False
elif isinstance(image, SpyFile):
if image.using_memmap is True:
data = image._memmap
src_interleave = {spectral.BSQ: 'bsq', spectral.BIL: 'bil',
spectral.BIP: 'bip'}[image.interleave]
swap = image.swap
else:
data = image.load(dtype=image.dtype, scale=False)
src_interleave = 'bip'
swap = False
if image.scale_factor != 1:
metadata['reflectance scale factor'] = image.scale_factor
else:
data = image.load()
src_interleave = 'bip'
swap = False
dtype = np.dtype(kwargs.get('dtype', data.dtype)).char
if dtype != data.dtype.char:
data = data.astype(dtype)
metadata['data type'] = dtype_to_envi[dtype]
# A few header parameters need to be set independent of what is provided
# in the supplied metadata.
# Always write data from start of file, regardless of what was in
# provided metadata.
offset = int(metadata.get('header offset', 0))
if offset != 0:
print 'Ignoring non-zero header offset in provided metadata.'
metadata['header offset'] = 0
metadata['lines'] = image.shape[0]
metadata['samples'] = image.shape[1]
if len(image.shape) == 3:
metadata['bands'] = image.shape[2]
else:
metadata['bands'] = 1
metadata['file type'] = 'ENVI Standard'
interleave = kwargs.get('interleave', 'bip').lower()
if interleave not in ['bil', 'bip', 'bsq']:
raise ValueError('Invalid interleave: %s'
% str(kwargs['interleave']))
if interleave != src_interleave:
data = data.transpose(interleave_transpose(src_interleave, interleave))
metadata['interleave'] = interleave
metadata['byte order'] = 1 if endian_out == 'big' else 0
if (endian_out == sys.byteorder and not data.dtype.isnative) or \
(endian_out != sys.byteorder and data.dtype.isnative):
data = data.byteswap()
if hasattr(image, 'bands'):
add_band_info_to_metadata(image.bands, metadata)
write_envi_header(hdr_file, metadata, is_library=False)
print 'Saving', img_file
bufsize = data.shape[0] * data.shape[1] * np.dtype(dtype).itemsize
fout = __builtin__.open(img_file, 'wb', bufsize)
fout.write(data.tostring())
fout.close()
def _prepared_data_and_metadata(hdr_file, image, **kwargs):
'''
Return data array and metadata dict representing `image`.
'''
import os
import sys
import spectral
from spectral.io.spyfile import SpyFile, interleave_transpose
endian_out = str(kwargs.get('byteorder', sys.byteorder)).lower()
if endian_out in ('0', 'little'):
endian_out = 'little'
elif endian_out in ('1', 'big'):
endian_out = 'big'
else:
raise ValueError('Invalid byte order: "%s".' % endian_out)
if isinstance(image, np.ndarray):
data = image
src_interleave = 'bip'
if len(data.shape) == 2:
data = data[:, :, np.newaxis]
swap = False
metadata = {}
elif isinstance(image, SpyFile):
if image.using_memmap is True:
data = image._memmap
src_interleave = {
spectral.BSQ: 'bsq',
spectral.BIL: 'bil',
spectral.BIP: 'bip'
}[image.interleave]
swap = image.swap
else:
data = image.load(dtype=image.dtype, scale=False)
src_interleave = 'bip'
swap = False
metadata = image.metadata.copy()
else:
data = image.load(scale=False)
src_interleave = 'bip'
swap = False
if hasattr(image, 'metadata'):
metadata = image.metadata.copy()
else:
metadata = {}
metadata.update(kwargs.get('metadata', {}))
add_image_info_to_metadata(image, metadata)
if hasattr(image, 'bands'):
add_band_info_to_metadata(image.bands, metadata)
dtype = np.dtype(kwargs.get('dtype', data.dtype)).char
_validate_dtype(dtype)
if dtype != data.dtype.char:
data = data.astype(dtype)
metadata['data type'] = dtype_to_envi[dtype]
interleave = kwargs.get('interleave', 'bip').lower()
if interleave not in ['bil', 'bip', 'bsq']:
raise ValueError('Invalid interleave: %s' % str(kwargs['interleave']))
if interleave != src_interleave:
data = data.transpose(interleave_transpose(src_interleave, interleave))
metadata['interleave'] = interleave
metadata['byte order'] = 1 if endian_out == 'big' else 0
if (endian_out == sys.byteorder and not data.dtype.isnative) or \
(endian_out != sys.byteorder and data.dtype.isnative):
data = data.byteswap()
return data, metadata
