# wrap VipsImage
from __future__ import division
import numbers
import struct
import pyvips
from pyvips import ffi, glib_lib, vips_lib, Error, _to_bytes, \
_to_string, _to_string_copy, GValue, at_least_libvips, Introspect
# either a single number, or a table of numbers
def _is_pixel(value):
return (isinstance(value, numbers.Number) or
(isinstance(value, list) and not
isinstance(value, pyvips.Image)))
# test for rectangular array of something
def _is_2D(array):
if not isinstance(array, list):
return False
for x in array:
if not isinstance(x, list):
return False
if len(x) != len(array[0]):
return False
return True
# apply a function to a thing, or map over a list
# we often need to do something like (1.0 / other) and need to work for lists
# as well as scalars
def _smap(func, x):
if isinstance(x, list):
return list(map(func, x))
else:
return func(x)
def _call_enum(image, other, base, operation):
if _is_pixel(other):
return pyvips.Operation.call(base + '_const', image, operation, other)
else:
return pyvips.Operation.call(base, image, other, operation)
def _run_cmplx(fn, image):
"""Run a complex function on a non-complex image.
The image needs to be complex, or have an even number of bands. The input
can be int, the output is always float or double.
"""
original_format = image.format
if image.format != 'complex' and image.format != 'dpcomplex':
if image.bands % 2 != 0:
raise Error('not an even number of bands')
if image.format != 'float' and image.format != 'double':
image = image.cast('float')
if image.format == 'double':
new_format = 'dpcomplex'
else:
new_format = 'complex'
image = image.copy(format=new_format, bands=image.bands / 2)
image = fn(image)
if original_format != 'complex' and original_format != 'dpcomplex':
if image.format == 'dpcomplex':
new_format = 'double'
else:
new_format = 'float'
image = image.copy(format=new_format, bands=image.bands * 2)
return image
# https://stackoverflow.com/a/22409540/1480019
# https://github.com/benjaminp/six/blob/33b584b2c551548021adb92a028ceaf892deb5be/six.py#L846-L861
def _with_metaclass(metaclass):
"""Class decorator for creating a class with a metaclass."""
def wrapper(cls):
orig_vars = cls.__dict__.copy()
slots = orig_vars.get('__slots__')
if slots is not None:
if isinstance(slots, str):
slots = [slots]
for slots_var in slots:
orig_vars.pop(slots_var)
orig_vars.pop('__dict__', None)
orig_vars.pop('__weakref__', None)
if hasattr(cls, '__qualname__'):
orig_vars['__qualname__'] = cls.__qualname__
return metaclass(cls.__name__, cls.__bases__, orig_vars)
return wrapper
# decorator to set docstring
def _add_doc(name):
try:
docstring = pyvips.Operation.generate_docstring(name)
except Error:
docstring = None
def _doc(func):
func.__doc__ = docstring
return func
return _doc
# decorator to set deprecated
def _deprecated(note):
def _dep(func):
func.__deprecated__ = note
return func
return _dep
# Rules for the mapping betweeen numpy typestrings and libvips formats
# b1: bool. Above u1 so that rev. map is uchar->u1
TYPESTR_TO_FORMAT = {'|b1': 'uchar',
'|u1': 'uchar',
'|i1': 'char',
'<u2': 'ushort',
'<i2': 'short',
'<u4': 'uint',
'<i4': 'int',
'<f4': 'float',
'<c8': 'complex',
'<f8': 'double',
'<c16': 'dpcomplex'}
# Rules for the mapping between libvips formats and numpy typestrings
FORMAT_TO_TYPESTR = dict((v, k) for k, v in TYPESTR_TO_FORMAT.items())
# see https://docs.python.org/3/library/struct.html
FORMAT_TO_PYFORMAT = {'uchar': 'B',
'char': 'c',
'ushort': 'H',
'short': 'h',
'uint': 'I',
'int': 'i',
'float': 'f',
'double': 'd',
'complex': 'f', # n.b. no support for complex in C
'dpcomplex': 'd'}
def _guess_interpretation(bands, format):
"""Return a best-guess interpretation string based on bands and libvips
format.
Args:
bands (int): Number of bands in the image.
format (str): libvips format string.
Returns:
str: the best-guess libvips interpretation string.
This function is a helper for :class:`.Image` creation from arrays when the
user specifies 'auto' for `interpretation`.
The heuristic used here can be defined in the following table::
| bands | format | interpretation | reason |
| ----- | --------- | -------------- | ------------ |
| 1 | uchar | b-w | L |
| 2 | uchar | b-w | LA |
| 3 | uchar | rgb | RGB |
| 4 | uchar | rgb | RGBA |
| 5+ | uchar | multiband | spectral |
| 1 | char | matrix | conv. kernel |
| 2+ | char | multiband | |
| 1 | ushort | grey16 | L |
| 2 | ushort | grey16 | LA |
| 3 | ushort | rgb16 | RGB |
| 4 | ushort | rgb16 | RGBA |
| 5+ | ushort | multiband | spectral |
| any | short | multiband | |
| 1 | float | b-w | L |
| 2 | float | b-w | LA |
| 3 | float | scrgb | RGB |
| 4 | float | scrgb | RGBA |
| 5+ | float | multiband | spectral |
| 1 | double | b-w | L |
| 2 | double | b-w | LA |
| 3 | double | scrgb | RGB |
| 4 | double | scrgb | RGBA |
| 5+ | double | multiband | spectral |
| any | complex | fourier | FFT |
| any | dpcomplex | fourier | FFT |
"""
if format not in FORMAT_TO_TYPESTR:
raise ValueError('Unknown format: {}'.format(format))
if not isinstance(bands, int) or bands < 1:
raise ValueError('Number of bands must be a positive integer.')
# the default
interp = 'multiband'
if format == 'uchar':
if bands in [1, 2]:
interp = 'b-w'
elif bands in [3, 4]:
interp = 'rgb'
elif format == 'char':
if bands == 1:
interp = 'matrix'
elif format == 'ushort':
if bands in [1, 2]:
interp = 'grey16'
elif bands in [3, 4]:
interp = 'rgb16'
elif format == 'short':
if bands == 1:
interp = 'matrix'
elif format in ['float', 'double']:
if bands in [1, 2]:
interp = 'b-w'
elif bands in [3, 4]:
interp = 'scrgb'
elif format in ['complex', 'dpcomplex']:
interp = 'fourier'
return interp
# metaclass for Image ... getattr on this implements the class methods
class ImageType(type):
def __getattr__(cls, name):
# logger.debug('ImageType.__getattr__ %s', name)
# does the method exist in libvips?
try:
# this will throw an exception if not
Introspect.get(name)
except Error:
# we need to throw this exception for missing methods, eg. numpy
# checks for this
raise AttributeError
@_add_doc(name)
def call_function(*args, **kwargs):
return pyvips.Operation.call(name, *args, **kwargs)
return call_function
[docs]@_with_metaclass(ImageType)
class Image(pyvips.VipsObject):
"""Wrap a VipsImage object.
"""
__slots__ = ('_references',)
# private static
@staticmethod
def _imageize(self, value):
# careful! self can be None if value is a 2D array
if isinstance(value, Image):
return value
elif _is_2D(value):
return Image.new_from_array(value)
else:
return self.new_from_image(value)
[docs] def __init__(self, pointer):
# a list of other objects which this object depends on and which need
# to be kept alive
# we can't use a set because set elements are unique under "==", and
# Python checks memoryview equality with hash functions, not pointer
# equality
self._references = []
# logger.debug('Image.__init__: pointer = %s', pointer)
super(Image, self).__init__(pointer)
# constructors
[docs] @staticmethod
def new_from_file(vips_filename, **kwargs):
"""Load an image from a file.
This method can load images in any format supported by vips. The
filename can include load options, for example::
image = pyvips.Image.new_from_file('fred.jpg[shrink=2]')
You can also supply options as keyword arguments, for example::
image = pyvips.Image.new_from_file('fred.jpg', shrink=2)
The full set of options available depend upon the load operation that
will be executed. Try something like::
$ vips jpegload
at the command-line to see a summary of the available options for the
JPEG loader.
Loading is fast: only enough of the image is loaded to be able to fill
out the header. Pixels will only be decompressed when they are needed.
Args:
vips_filename (str): The disc file to load the image from, with
optional appended arguments.
All loaders support at least the following options:
Keyword args:
memory (bool): If set True, load the image via memory rather than
via a temporary disc file. See :meth:`.new_temp_file` for
notes on where temporary files are created. Small images are
loaded via memory by default, use ``VIPS_DISC_THRESHOLD`` to
set the definition of small.
access (Access): Hint the expected access pattern for the image.
fail (bool): If set True, the loader will fail with an error on
the first serious error in the file. By default, libvips
will attempt to read everything it can from a damaged image.
Returns:
A new :class:`.Image`.
Raises:
:class:`.Error`
"""
vips_filename = _to_bytes(vips_filename)
pointer = vips_lib.vips_filename_get_filename(vips_filename)
filename = _to_string_copy(pointer)
pointer = vips_lib.vips_filename_get_options(vips_filename)
options = _to_string_copy(pointer)
pointer = vips_lib.vips_foreign_find_load(vips_filename)
if pointer == ffi.NULL:
raise Error('unable to load from file {0}'.format(vips_filename))
name = _to_string(pointer)
return pyvips.Operation.call(name, filename,
string_options=options, **kwargs)
[docs] @staticmethod
def new_from_buffer(data, options, **kwargs):
"""Load a formatted image from memory.
This behaves exactly as :meth:`new_from_file`, but the image is
loaded from the memory object rather than from a file. The memory
object can be anything that supports the Python buffer protocol.
Args:
data (array, bytearray, bytes, buffer): The memory object to
load the image from.
options (str): Load options as a string. Use ``""`` for no options.
All loaders support at least the following options:
Keyword args:
access (Access): Hint the expected access pattern for the image.
fail (bool): If set True, the loader will fail with an error on the
first serious error in the image. By default, libvips will
attempt to read everything it can from a damaged image.
Returns:
A new :class:`Image`.
Raises:
:class:`.Error`
"""
pointer = vips_lib.vips_foreign_find_load_buffer(data, len(data))
if pointer == ffi.NULL:
raise Error('unable to load from buffer')
name = _to_string(pointer)
return pyvips.Operation.call(name, data,
string_options=options, **kwargs)
[docs] @staticmethod
def new_from_list(array, scale=1.0, offset=0.0):
"""Create an image from a list or list of lists.
A new one-band image with :class:`BandFormat` ``'double'`` pixels is
created from the array. These image are useful with the libvips
convolution operator :meth:`Image.conv`.
Args:
array (list[list[float]]): Create the image from these values.
1D arrays become a single row of pixels.
scale (float): Default to 1.0. What to divide each pixel by after
convolution. Useful for integer convolution masks.
offset (float): Default to 0.0. What to subtract from each pixel
after convolution. Useful for integer convolution masks.
Returns:
A new :class:`Image`.
Raises:
:class:`.Error`
"""
if not _is_2D(array):
array = [array]
height = len(array)
width = len(array[0])
n = width * height
a = ffi.new('double[]', n)
for y in range(0, height):
for x in range(0, width):
a[x + y * width] = array[y][x]
vi = vips_lib.vips_image_new_matrix_from_array(width, height, a, n)
if vi == ffi.NULL:
raise Error('unable to make image from matrix')
image = pyvips.Image(vi)
image.set_type(GValue.gdouble_type, 'scale', scale)
image.set_type(GValue.gdouble_type, 'offset', offset)
return image
[docs] @classmethod
def new_from_array(cls, obj, scale=1.0, offset=0.0, interpretation=None):
"""Create a new Image from a list or an array-like object.
Array-like objects are those which define `__array_interface__` or
`__array__`. For details about the array interface, see `The Array
Interface
<https://numpy.org/doc/stable/reference/arrays.interface.html>`_.
If `__array_interface__` is not available, `__array__` is used as a
fallback.
The behavior for input objects with different dimensions is summarized
as::
| array ndim | array shape | Image w | Image h | Image bands |
|------------|-------------|---------|---------|-------------|
| 0 | () | 1 | 1 | 1 |
| 1 | (W,) | W | 1 | 1 |
| 2 | (H, W) | W | H | 1 |
| 3 | (H, W, C) | W | H | C |
Args:
obj (list or object width `__array_interface__` or `__array__`):
The object to convert to an image.
If the input object is a list, `Image.new_from_list` is used
with the given `scale` and `offset`
If the input object is an array-like object, a new image is
created from the object's data and shape. The memory is shared
except in the following cases:
- The object's memory is not contiguous. In this case, a copy
is made by attempting to call the object's `tobytes()` method
or its `tostring()` method.
- The object is an array of bools, in which case it is
converted to a pyvips uchar image with True values becoming
255 and False values becoming 0.
scale (float): Default to 1.0. **Ignored for non-list inputs**.
What to divide each pixel by after convolution. Useful for
integer convolution masks.
offset (float): Default to 0.0. **Ignored for non-list inputs**.
What to subtract from each pixel after convolution. Useful for
integer convolution masks.
interpretation (str, optional): **Ignored for list inputs** The
libvips interpretation of the array. If None, the
interpretation defaults to the pyvips one for
`Image.new_from_memory`.
If 'auto', a heuristic is used to determine a best-guess
interpretation as defined in the `_guess_interpretation`
function.
Must be one of None, 'auto', 'error', 'multiband', 'b-w',
'histogram', 'xyz', 'lab', 'cmyk', 'labq', 'rgb', 'cmc', 'lch',
'labs', 'srgb', 'yxy', 'fourier', 'rgb16', 'grey16', 'matrix',
'scrgb', or 'hsv'
Returns:
The new image.
See Also:
:func:`_guess_interpretation`
"""
if isinstance(obj, list):
return cls.new_from_list(obj, scale, offset)
if hasattr(obj, '__array_interface__'):
a = obj.__array_interface__
shape = a['shape']
typestr = a['typestr']
ndim = len(shape)
# strides is optional
strides = a.get('strides', None)
if ndim > 3:
raise ValueError('array has more than 3 dimensions')
if typestr not in TYPESTR_TO_FORMAT:
raise ValueError('conversion from {0} not supported'
.format(typestr))
if ndim == 0:
width = 1
height = 1
bands = 1
elif ndim == 1:
width = shape[0]
height = 1
bands = 1
elif ndim == 2:
height, width = shape
bands = 1
elif ndim == 3:
height, width, bands = shape
format = TYPESTR_TO_FORMAT[typestr]
if strides is None and hasattr(obj, 'data'):
data = obj.data
else:
# To obtain something with a contiguous memory layout
if hasattr(obj, 'tobytes'):
data = obj.tobytes()
elif hasattr(obj, 'tostring'):
data = obj.tostring()
else:
raise TypeError('object has no .tobytes or .tostring')
im = cls.new_from_memory(
data,
width,
height,
bands,
format
)
if typestr == '|b1':
# special case for bool: true in vips is uchar(255)
im = im.ifthenelse(255, 0)
if interpretation is not None:
if interpretation == 'auto':
interpretation = _guess_interpretation(bands, format)
im = im.copy(interpretation=interpretation)
return im
elif hasattr(obj, '__array__'):
# make it into something that *does* define __array_interface__
return cls.new_from_array(obj.__array__())
else:
raise TypeError('does not define __array_interface__ '
'or __array__')
[docs] @staticmethod
def new_from_memory(data, width, height, bands, format):
"""Wrap an image around a memory array.
Wraps an Image around an area of memory containing a C-style array. For
example, if the ``data`` memory array contains four bytes with the
values 1, 2, 3, 4, you can make a one-band, 2x2 uchar image from
it like this::
image = Image.new_from_memory(data, 2, 2, 1, 'uchar')
A reference is kept to the data object, so it will not be
garbage-collected until the returned image is garbage-collected.
This method is useful for efficiently transferring images from PIL or
NumPy into libvips.
See :meth:`.write_to_memory` for the opposite operation.
Use :meth:`.copy` to set other image attributes.
Args:
data (bytes): A memoryview or buffer object.
width (int): Image width in pixels.
height (int): Image height in pixels.
bands (int): Number of bands.
format (BandFormat): Band format.
Returns:
A new :class:`Image`.
Raises:
:class:`.Error`
"""
format_value = GValue.to_enum(GValue.format_type, format)
pointer = ffi.from_buffer(data)
# py3:
# - memoryview has .nbytes for number of bytes in object
# - len() returns number of elements in top array
# py2:
# - buffer has no nbytes member
# - but len() gives number of bytes in object
nbytes = data.nbytes if hasattr(data, 'nbytes') else len(data)
vi = vips_lib.vips_image_new_from_memory(pointer,
nbytes,
width, height, bands,
format_value)
if vi == ffi.NULL:
raise Error('unable to make image from memory')
image = pyvips.Image(vi)
# keep a secret ref to the underlying object .. this reference will be
# inherited by things that in turn depend on us, so the memory we are
# using will not be freed
image._references.append(data)
return image
[docs] @staticmethod
def new_from_source(source, options, **kwargs):
"""Load a formatted image from a source.
This behaves exactly as :meth:`new_from_file`, but the image is
loaded from the source rather than from a file.
Args:
source (Source): The source to load the image from.
options (str): Load options as a string. Use ``""`` for no options.
All loaders support at least the following options:
Keyword args:
access (Access): Hint the expected access pattern for the image.
fail (bool): If set True, the loader will fail with an error on the
first serious error in the image. By default, libvips will
attempt to read everything it can from a damaged image.
Returns:
A new :class:`Image`.
Raises:
:class:`.Error`
"""
pointer = vips_lib.vips_foreign_find_load_source(source.pointer)
if pointer == ffi.NULL:
raise Error('unable to load from source')
name = _to_string(pointer)
return pyvips.Operation.call(name, source,
string_options=options, **kwargs)
[docs] @staticmethod
def new_temp_file(format):
"""Make a new temporary image.
Returns an image backed by a temporary file. When written to with
:func:`Image.write`, a temporary file will be created on disc in the
specified format. When the image is closed, the file will be deleted
automatically.
The file is created in the temporary directory. This is set with
the environment variable ``TMPDIR``. If this is not set, then on
Unix systems, vips will default to ``/tmp``. On Windows, vips uses
``GetTempPath()`` to find the temporary directory.
vips uses ``g_mkstemp()`` to make the temporary filename. They
generally look something like ``"vips-12-EJKJFGH.v"``.
Args:
format (str): The format for the temp file, for example
``"%s.v"`` for a vips format file. The ``%s`` is
substituted by the file path.
Returns:
A new :class:`Image`.
Raises:
:class:`.Error`
"""
vi = vips_lib.vips_image_new_temp_file(_to_bytes(format))
if vi == ffi.NULL:
raise Error('unable to make temp file')
return pyvips.Image(vi)
[docs] def new_from_image(self, value):
"""Make a new image from an existing one.
A new image is created which has the same size, format, interpretation
and resolution as ``self``, but with every pixel set to ``value``.
Args:
value (float, list[float]): The value for the pixels. Use a
single number to make a one-band image; use an array constant
to make a many-band image.
Returns:
A new :class:`Image`.
Raises:
:class:`.Error`
"""
pixel = (Image.black(1, 1) + value).cast(self.format)
image = pixel.embed(0, 0, self.width, self.height,
extend='copy')
image = image.copy(interpretation=self.interpretation,
xres=self.xres,
yres=self.yres,
xoffset=self.xoffset,
yoffset=self.yoffset)
return image
[docs] def copy_memory(self):
"""Copy an image to memory.
A large area of memory is allocated, the image is rendered to that
memory area, and a new image is returned which wraps that large memory
area.
Returns:
A new :class:`Image`.
Raises:
:class:`.Error`
"""
vi = vips_lib.vips_image_copy_memory(self.pointer)
if vi == ffi.NULL:
raise Error('unable to copy to memory')
return pyvips.Image(vi)
# writers
[docs] def write_to_file(self, vips_filename, **kwargs):
"""Write an image to a file on disc.
This method can save images in any format supported by vips. The format
is selected from the filename suffix. The filename can include embedded
save options, see :func:`Image.new_from_file`.
For example::
image.write_to_file('fred.jpg[Q=95]')
You can also supply options as keyword arguments, for example::
image.write_to_file('fred.jpg', Q=95)
The full set of options available depend upon the load operation that
will be executed. Try something like::
$ vips jpegsave
at the command-line to see a summary of the available options for the
JPEG saver.
Args:
vips_filename (str): The disc file to save the image to, with
optional appended arguments.
Other arguments depend upon the save operation.
Returns:
None
Raises:
:class:`.Error`
"""
vips_filename = _to_bytes(vips_filename)
pointer = vips_lib.vips_filename_get_filename(vips_filename)
filename = _to_string_copy(pointer)
pointer = vips_lib.vips_filename_get_options(vips_filename)
options = _to_string_copy(pointer)
pointer = vips_lib.vips_foreign_find_save(vips_filename)
if pointer == ffi.NULL:
raise Error('unable to write to file {0}'.format(vips_filename))
name = _to_string(pointer)
return pyvips.Operation.call(name, self, filename,
string_options=options, **kwargs)
[docs] def write_to_buffer(self, format_string, **kwargs):
"""Write an image to memory.
This method can save images in any format supported by vips. The format
is selected from the suffix in the format string. This can include
embedded save options, see :func:`Image.write_to_file`.
For example::
data = image.write_to_buffer('.jpg[Q=95]')
You can also supply options as keyword arguments, for example::
data = image.write_to_buffer('.jpg', Q=95)
The full set of options available depend upon the load operation that
will be executed. Try something like::
$ vips jpegsave_buffer
at the command-line to see a summary of the available options for the
JPEG saver.
Args:
format_string (str): The suffix, plus any string-form arguments.
Other arguments depend upon the save operation.
Returns:
A byte string.
Raises:
:class:`.Error`
"""
format_string = _to_bytes(format_string)
filename = vips_lib.vips_filename_get_filename(format_string)
pointer = vips_lib.vips_filename_get_options(format_string)
options = _to_string_copy(pointer)
pointer = ffi.NULL
if at_least_libvips(8, 9):
vips_lib.vips_error_freeze()
pointer = vips_lib.vips_foreign_find_save_target(filename)
vips_lib.vips_error_thaw()
if pointer != ffi.NULL:
name = _to_string(pointer)
target = pyvips.Target.new_to_memory()
pyvips.Operation.call(name, self, target,
string_options=options, **kwargs)
buffer = target.get("blob")
else:
pointer = vips_lib.vips_foreign_find_save_buffer(filename)
if pointer == ffi.NULL:
raise Error('unable to write to buffer')
name = _to_string(pointer)
buffer = pyvips.Operation.call(name, self,
string_options=options, **kwargs)
return buffer
[docs] def write_to_target(self, target, format_string, **kwargs):
"""Write an image to a target.
This method will write the image to the target in the format
specified in the suffix in the format string. This can include
embedded save options, see :func:`Image.write_to_file`.
For example::
image.write_to_target(target, '.jpg[Q=95]')
You can also supply options as keyword arguments, for example::
image.write_to_target(target, '.jpg', Q=95)
The full set of options available depend upon the save operation that
will be executed. Try something like::
$ vips jpegsave_target
at the command-line to see a summary of the available options for the
JPEG saver.
Args:
target (Target): The target to write the image to
format_string (str): The suffix, plus any string-form arguments.
Other arguments depend upon the save operation.
Returns:
None
Raises:
:class:`.Error`
"""
format_string = _to_bytes(format_string)
pointer = vips_lib.vips_filename_get_options(format_string)
options = _to_string_copy(pointer)
pointer = vips_lib.vips_foreign_find_save_target(format_string)
if pointer == ffi.NULL:
raise Error('unable to write to target')
name = _to_string(pointer)
return pyvips.Operation.call(name, self, target,
string_options=options, **kwargs)
[docs] def write_to_memory(self):
"""Write the image to a large memory array.
A large area of memory is allocated, the image is rendered to that
memory array, and the array is returned as a buffer.
For example, if you have a 2x2 uchar image containing the bytes 1, 2,
3, 4, read left-to-right, top-to-bottom, then::
buf = image.write_to_memory()
will return a four byte buffer containing the values 1, 2, 3, 4.
Returns:
buffer
Raises:
:class:`.Error`
"""
psize = ffi.new('size_t *')
pointer = vips_lib.vips_image_write_to_memory(self.pointer, psize)
if pointer == ffi.NULL:
raise Error('unable to write to memory')
pointer = ffi.gc(pointer, glib_lib.g_free)
return ffi.buffer(pointer, psize[0])
[docs] def write(self, other):
"""Write an image to another image.
This function writes ``self`` to another image. Use something like
:func:`Image.new_temp_file` to make an image that can be written to.
Args:
other (Image): The :class:`Image` to write to,
Returns:
None
Raises:
:class:`.Error`
"""
result = vips_lib.vips_image_write(self.pointer, other.pointer)
if result != 0:
raise Error('unable to write to image')
[docs] def invalidate(self):
"""Drop caches on an image, and any downstream images.
This method drops all pixel caches on an image and on all downstream
images. Any operations which depend on this image, directly or
indirectly, are also dropped from the libvips operation cache.
This method can be useful if you wrap a libvips image around an area
of memory with :meth:`.new_from_memory` and then change some bytes
without libvips knowing.
Returns:
None
"""
vips_lib.vips_image_invalidate_all(self.pointer)
[docs] def set_progress(self, progress):
"""Enable progress reporting on an image.
When progress reporting is enabled, evaluation of the most downstream
image from this image will report progress using the ::preeval, ::eval,
and ::posteval signals.
"""
vips_lib.vips_image_set_progress(self.pointer, progress)
[docs] def set_kill(self, kill):
"""Kill processing of an image.
Use this to kill evaluation of an image. You can call it from one of
the progress signals, for example. See :meth:`.set_progress`.
"""
vips_lib.vips_image_set_kill(self.pointer, kill)
# get/set metadata
[docs] def get_typeof(self, name):
"""Get the GType of an item of metadata.
Fetch the GType of a piece of metadata, or 0 if the named item does not
exist. See :class:`GValue`.
Args:
name (str): The name of the piece of metadata to get the type of.
Returns:
The ``GType``, or 0.
Raises:
None
"""
# on libvips before 8.5, property types must be fetched separately,
# since built-in enums were reported as ints
if not at_least_libvips(8, 5):
gtype = super(Image, self).get_typeof(name)
if gtype != 0:
return gtype
return vips_lib.vips_image_get_typeof(self.pointer, _to_bytes(name))
[docs] def get(self, name):
"""Get an item of metadata.
Fetches an item of metadata as a Python value. For example::
orientation = image.get('orientation')
would fetch the image orientation.
Args:
name (str): The name of the piece of metadata to get.
Returns:
The metadata item as a Python value.
Raises:
:class:`.Error`
"""
# with old libvips, we must fetch properties (as opposed to
# metadata) via VipsObject
if not at_least_libvips(8, 5):
gtype = super(Image, self).get_typeof(name)
if gtype != 0:
return super(Image, self).get(name)
gv = GValue()
result = vips_lib.vips_image_get(self.pointer, _to_bytes(name),
gv.pointer)
if result != 0:
raise Error('unable to get {0}'.format(name))
return gv.get()
[docs] def get_fields(self):
"""Get a list of all the metadata fields on an image.
Returns:
[string]
"""
names = []
if at_least_libvips(8, 5):
array = vips_lib.vips_image_get_fields(self.pointer)
i = 0
while array[i] != ffi.NULL:
name = _to_string(array[i])
names.append(name)
glib_lib.g_free(array[i])
i += 1
glib_lib.g_free(array)
return names
[docs] def set_type(self, gtype, name, value):
"""Set the type and value of an item of metadata.
Sets the type and value of an item of metadata. Any old item of the
same name is removed. See :class:`GValue` for types.
Args:
gtype (int): The GType of the metadata item to create.
name (str): The name of the piece of metadata to create.
value (mixed): The value to set as a Python value. It is
converted to the ``gtype``, if possible.
Returns:
None
Raises:
None
"""
gv = GValue()
gv.set_type(gtype)
gv.set(value)
vips_lib.vips_image_set(self.pointer, _to_bytes(name), gv.pointer)
[docs] def set(self, name, value):
"""Set the value of an item of metadata.
Sets the value of an item of metadata. The metadata item must already
exist.
Args:
name (str): The name of the piece of metadata to set the value of.
value (mixed): The value to set as a Python value. It is
converted to the type of the metadata item, if possible.
Returns:
None
Raises:
:class:`.Error`
"""
gtype = self.get_typeof(name)
if gtype == 0:
raise Error('metadata item {0} does not exist - '
'use set_type() to create and set'.format(name))
self.set_type(gtype, name, value)
[docs] def remove(self, name):
"""Remove an item of metadata.
The named metadata item is removed.
Args:
name (str): The name of the piece of metadata to remove.
Returns:
None
Raises:
None
"""
return vips_lib.vips_image_remove(self.pointer, _to_bytes(name)) != 0
[docs] def tolist(self):
"""Return a single-band image as a list of lists.
Returns:
list of lists of values
"""
if not self.bands == 1:
raise NotImplementedError('tolist only implemented for ' +
'single-band images')
is_complex = self.format in ['complex', 'dpcomplex']
row_els = self.width if not is_complex else 2 * self.width
rowfmt = '{0}{1}'.format(row_els, FORMAT_TO_PYFORMAT[self.format])
buf = self.write_to_memory()
lst = [list(row) for row in struct.iter_unpack(rowfmt, buf)]
if is_complex:
lst = [[r[i] + 1j*r[i+1] for i in range(0, row_els, 2)]
for r in lst]
return lst
# Following will be relevant if we expose the buffer interface:
# @property
# def __array_interface__(self):
# """Return a numpy-standard __array_interface__ dictionary.
#
# This is used by some libraries (PIL, e.g.) to interpret the image
# as an array.
#
# See https://numpy.org/doc/stable/reference/arrays.interface.html for
# more info.
#
# """
# if self.bands == 1:
# shape = (self.height, self.width)
# else:
# shape = (self.height, self.width, self.bands)
#
# typestr = FORMAT_TO_TYPESTR[self.format]
#
# interface = {
# 'shape': shape,
# 'strides': None,
# 'descr': [('', typestr)],
# 'typestr': typestr,
# 'version': 3
# }
#
# return interface
[docs] def __array__(self, dtype=None):
"""Conversion to a NumPy array.
Args:
dtype (str or numpy dtype, optional) The dtype to use for the
numpy array. If None, the default dtype of the image is used
as defined the global `FORMAT_TO_TYPESTR` dictionary.
Returns:
numpy.ndarray: The array representation of the image.
* Single-band images lose their channel axis.
* Single-pixel single-band images are converted to a 0D array.
See https://numpy.org/devdocs/user/basics.dispatch.html for more
details.
This enables a :class:`Image` to be used where a numpy array is
expected, including in plotting and conversion to other array
container types (pytorch, JAX, dask, etc.), for example.
`numpy` is a runtime dependency of this function.
See Also `Image.new_from_array` for the inverse operation. #TODO
"""
import numpy as np
arr = (
np.frombuffer(self.write_to_memory(),
dtype=FORMAT_TO_TYPESTR[self.format])
.reshape(self.height, self.width, self.bands)
)
if self.bands == 1:
# flatten single-band images
arr = arr.squeeze(axis=-1)
if self.width == 1 and self.height == 1:
# flatten single-pixel single-band images
arr = arr.squeeze(axis=(0, 1))
if dtype is not None:
arr = arr.astype(dtype)
return arr
[docs] def numpy(self, dtype=None):
"""Convenience function to allow numpy conversion to be at the end
of a method chain.
This mimics the behavior of pytorch: ``arr = im.op1().op2().numpy()``
numpy is a runtime dependency of this function.
Args:
dtype (str or numpy dtype): The dtype to use for the numpy array.
If None, the default dtype of the image is used.
Returns:
numpy.ndarray: The image as a numpy array.
See Also:
- :meth:`.__array__`
- `FORMAT_TO_TYPESTR`: Global dictionary mapping libvips format
strings to numpy dtype strings.
"""
return self.__array__(dtype=dtype)
[docs] def __repr__(self):
if (
self.interpretation == "matrix"
and self.width < 20
and self.height < 20
and self.bands == 1
):
array = self.tolist()
return repr(array)
else:
return ('<pyvips.Image {0}x{1} {2}, {3} bands, {4}>'.
format(self.width, self.height, self.format, self.bands,
self.interpretation))
[docs] def __getattr__(self, name):
"""Divert unknown names to libvips.
Unknown attributes are first looked up in the image properties as
accessors, for example::
width = image.width
and then in the libvips operation table, where they become method
calls, for example::
new_image = image.invert()
Use :func:`get` to fetch image metadata.
A ``__getattr__`` on the metatype lets you call static members in the
same way.
Args:
name (str): The name of the piece of metadata to get.
Returns:
Mixed.
Raises:
:class:`.Error`
"""
# logger.debug('Image.__getattr__ %s', name)
# scale and offset have default values
if name == 'scale':
if self.get_typeof('scale') != 0:
return self.get('scale')
else:
return 1.0
if name == 'offset':
if self.get_typeof('offset') != 0:
return self.get('offset')
else:
return 0.0
# look up in props first (but not metadata)
if super(Image, self).get_typeof(name) != 0:
return super(Image, self).get(name)
# does the method exist in libvips?
try:
# this will throw an exception if not
Introspect.get(name)
except Error:
# we need to throw this exception for missing methods, eg. numpy
# checks for this
raise AttributeError
@_add_doc(name)
def call_function(*args, **kwargs):
return pyvips.Operation.call(name, self, *args, **kwargs)
return call_function
# compatibility methods
@_deprecated('use Image.get() instead')
def get_value(self, name):
return self.get(name)
@_deprecated('use Image.set() instead')
def set_value(self, name, value):
self.set(name, value)
@_deprecated('use Image.scale instead')
def get_scale(self):
return self.scale
@_deprecated('use Image.offset instead')
def get_offset(self):
return self.offset
# support with in the most trivial way
def __enter__(self):
return self
def __exit__(self, type, value, traceback):
pass
[docs] def __getitem__(self, arg):
"""Overload [] to pull out band elements from an image.
The following arguments types are accepted:
* int::
green = rgb_image[1]
Will make a new one-band image from band 1 (the middle band).
* slice::
last_two = rgb_image[1:]
last_band = rgb_image[-1]
middle_few = multiband[1:-2]
reversed = multiband[::-1]
every_other = multiband[::2]
other_every_other = multiband[1::2]
* list of int::
# list of integers
desired_bands = [1, 2, 2, -1]
four_band = multiband[desired_bands]
* list of bool::
wanted_bands = [True, False, True, True, False]
three_band = five_band[wanted_bands]
In the case of integer or slice arguments, the semantics of slicing
exactly match those of slicing `range(self.bands)`.
In the case of list arguments, the semantics match those of numpy's
extended slicing syntax. Thus, lists of booleans must have as many
elements as there are bands in the image.
"""
if isinstance(arg, int):
# raises IndexError for bad integer indices
i = range(self.bands)[arg]
n = 1
elif isinstance(arg, slice):
band_seq = range(self.bands)[arg]
if len(band_seq) == 0:
raise IndexError('empty slice')
i = band_seq[0]
n = len(band_seq)
elif isinstance(arg, list):
if not arg:
raise IndexError('empty list')
# n.b. We don't use isinstance because isinstance(True, int)
# is True!
if not (all(type(x) == int for x in arg) or
all(type(x) == bool for x in arg)):
raise IndexError('list must contain only ints or only bools')
if isinstance(arg[0], bool):
if len(arg) != self.bands:
raise IndexError('boolean index must have same ' +
'length as bands')
band_seq = [i for i, x in enumerate(arg) if x]
n = len(band_seq)
if n == 0:
raise IndexError('empty boolean index')
if n == 1:
i = band_seq[0]
else:
all_bands = range(self.bands)
# raises IndexError for bad int indices
band_seq = [all_bands[i] for i in arg]
n = len(band_seq)
if n == 1:
i = band_seq[0]
else:
raise IndexError('argument must be an int, slice, ' +
'list of ints, or list of bools')
if n == 1:
# int or 1-element selection
return self.extract_band(i)
elif isinstance(arg, slice) and arg.step == 1:
# sequential multi-band slice
return self.extract_band(i, n=n)
else:
# nonsequential slice, list of ints, or list of bools
bands = [self.extract_band(x) for x in band_seq]
return bands[0].bandjoin(bands[1:])
# overload () to mean fetch pixel
[docs] def __call__(self, x, y):
"""Fetch a pixel value.
Args:
x (int): The x coordinate to fetch.
y (int): The y coordinate to fetch.
Returns:
Pixel as an array of floating point numbers.
Raises:
:class:`.Error`
"""
return self.getpoint(x, y)
# operator overloads
def __add__(self, other):
if isinstance(other, pyvips.Image):
return self.add(other)
else:
return self.linear(1, other)
def __radd__(self, other):
return self.__add__(other)
def __sub__(self, other):
if isinstance(other, pyvips.Image):
return self.subtract(other)
else:
return self.linear(1, _smap(lambda x: -1 * x, other))
def __rsub__(self, other):
return self.linear(-1, other)
def __mul__(self, other):
if isinstance(other, Image):
return self.multiply(other)
else:
return self.linear(other, 0)
def __rmul__(self, other):
return self.__mul__(other)
# a / const has always been a float in vips, so div and truediv are the
# same
def __div__(self, other):
if isinstance(other, pyvips.Image):
return self.divide(other)
else:
return self.linear(_smap(lambda x: 1.0 / x, other), 0)
def __rdiv__(self, other):
return (self ** -1) * other
def __truediv__(self, other):
return self.__div__(other)
def __rtruediv__(self, other):
return self.__rdiv__(other)
def __floordiv__(self, other):
if isinstance(other, pyvips.Image):
return self.divide(other).floor()
else:
return self.linear(_smap(lambda x: 1.0 / x, other), 0).floor()
def __rfloordiv__(self, other):
return ((self ** -1) * other).floor()
def __mod__(self, other):
if isinstance(other, pyvips.Image):
return self.remainder(other)
else:
return self.remainder_const(other)
def __pow__(self, other):
return _call_enum(self, other, 'math2', 'pow')
def __rpow__(self, other):
return _call_enum(self, other, 'math2', 'wop')
def __abs__(self):
return self.abs()
def __lshift__(self, other):
return _call_enum(self, other, 'boolean', 'lshift')
def __rshift__(self, other):
return _call_enum(self, other, 'boolean', 'rshift')
def __and__(self, other):
return _call_enum(self, other, 'boolean', 'and')
def __rand__(self, other):
return self.__and__(other)
[docs] def __or__(self, other):
return _call_enum(self, other, 'boolean', 'or')
[docs] def __ror__(self, other):
return self.__or__(other)
def __xor__(self, other):
return _call_enum(self, other, 'boolean', 'eor')
def __rxor__(self, other):
return self.__xor__(other)
def __neg__(self):
return -1 * self
def __pos__(self):
return self
def __invert__(self):
return self ^ -1
[docs] def __gt__(self, other):
return _call_enum(self, other, 'relational', 'more')
[docs] def __ge__(self, other):
return _call_enum(self, other, 'relational', 'moreeq')
[docs] def __lt__(self, other):
return _call_enum(self, other, 'relational', 'less')
[docs] def __le__(self, other):
return _call_enum(self, other, 'relational', 'lesseq')
[docs] def __eq__(self, other):
# _eq version allows comparison to None
if other is None:
return False
return _call_enum(self, other, 'relational', 'equal')
[docs] def __ne__(self, other):
# _eq version allows comparison to None
if other is None:
return True
return _call_enum(self, other, 'relational', 'noteq')
[docs] def floor(self):
"""Return the largest integral value not greater than the argument."""
return self.round('floor')
[docs] def ceil(self):
"""Return the smallest integral value not less than the argument."""
return self.round('ceil')
[docs] def rint(self):
"""Return the nearest integral value."""
return self.round('rint')
[docs] def bandand(self):
"""AND image bands together."""
return self.bandbool('and')
[docs] def bandor(self):
"""OR image bands together."""
return self.bandbool('or')
[docs] def bandeor(self):
"""EOR image bands together."""
return self.bandbool('eor')
[docs] def bandsplit(self):
"""Split an n-band image into n separate images."""
return [x for x in self]
[docs] def bandjoin(self, other):
"""Append a set of images or constants bandwise."""
if not isinstance(other, list):
other = [other]
# guard against empty list
if not other:
return self
# if [other] is all numbers, we can use bandjoin_const
non_number = next((x for x in other
if not isinstance(x, numbers.Number)),
None)
if non_number is None:
return self.bandjoin_const(other)
else:
return pyvips.Operation.call('bandjoin', [self] + other)
def atan2(self, other):
return _call_enum(self, other, 'math2', 'atan2')
[docs] def get_n_pages(self):
"""Get the number of pages in an image file, or 1.
This is the number of pages in the file the image was loaded from, not
the number of pages in the image.
To get the number of pages in an image, divide the image height by
the page height.
"""
if at_least_libvips(8, 8):
return vips_lib.vips_image_get_n_pages(self.pointer)
else:
return self.get("n-pages") \
if self.get_typeof("n-pages") != 0 else 1
[docs] def get_page_height(self):
"""Get the page height in a many-page image, or height.
"""
if at_least_libvips(8, 8):
return vips_lib.vips_image_get_page_height(self.pointer)
else:
if self.get_typeof("page-height") != 0:
page_height = self.get("page-height")
else:
page_height = self.height
if page_height > 0 and \
page_height <= self.height and \
self.height % page_height == 0:
return page_height
else:
return self.height
[docs] def pagesplit(self):
"""Split an N-page image into a list of N separate images.
"""
page_height = self.get_page_height()
return [self.crop(0, y, self.width, page_height)
for y in range(0, self.height, page_height)]
[docs] def pagejoin(self, other):
"""Join a set of pages vertically to make a multipage image.
Also sets the page-height property on the result.
"""
if not isinstance(other, list):
other = [other]
n_pages = 1 + len(other)
image = Image.arrayjoin([self] + other, across=1)
image = image.copy()
image.set_type(GValue.gint_type, 'page-height', image.height / n_pages)
return image
[docs] def composite(self, other, mode, **kwargs):
"""Composite a set of images with a set of modes."""
if not isinstance(other, list):
other = [other]
if not isinstance(mode, list):
mode = [mode]
# modes are VipsBlendMode enums, but we have to pass as array of int --
# we need to map str->int by hand
mode = [GValue.to_enum(GValue.blend_mode_type, x) for x in mode]
return pyvips.Operation.call('composite', [self] + other, mode,
**kwargs)
[docs] def bandrank(self, other, **kwargs):
"""Band-wise rank filter a set of images."""
if not isinstance(other, list):
other = [other]
return pyvips.Operation.call('bandrank', [self] + other, **kwargs)
[docs] def maxpos(self):
"""Return the coordinates of the image maximum."""
v, opts = self.max(x=True, y=True)
x = opts['x']
y = opts['y']
return v, x, y
[docs] def minpos(self):
"""Return the coordinates of the image minimum."""
v, opts = self.min(x=True, y=True)
x = opts['x']
y = opts['y']
return v, x, y
[docs] def real(self):
"""Return the real part of a complex image."""
return self.complexget('real')
[docs] def imag(self):
"""Return the imaginary part of a complex image."""
return self.complexget('imag')
[docs] def polar(self):
"""Return an image converted to polar coordinates."""
return _run_cmplx(lambda x: x.complex('polar'), self)
[docs] def rect(self):
"""Return an image converted to rectangular coordinates."""
return _run_cmplx(lambda x: x.complex('rect'), self)
[docs] def conj(self):
"""Return the complex conjugate of an image."""
return self.complex('conj')
[docs] def sin(self):
"""Return the sine of an image in degrees."""
return self.math('sin')
[docs] def cos(self):
"""Return the cosine of an image in degrees."""
return self.math('cos')
[docs] def tan(self):
"""Return the tangent of an image in degrees."""
return self.math('tan')
[docs] def asin(self):
"""Return the inverse sine of an image in degrees."""
return self.math('asin')
[docs] def acos(self):
"""Return the inverse cosine of an image in degrees."""
return self.math('acos')
[docs] def atan(self):
"""Return the inverse tangent of an image in degrees."""
return self.math('atan')
[docs] def sinh(self):
"""Return the hyperbolic sine of an image in radians."""
return self.math('sinh')
[docs] def cosh(self):
"""Return the hyperbolic cosine of an image in radians."""
return self.math('cosh')
[docs] def tanh(self):
"""Return the hyperbolic tangent of an image in radians."""
return self.math('tanh')
[docs] def asinh(self):
"""Return the inverse hyperbolic sine of an image in radians."""
return self.math('asinh')
[docs] def acosh(self):
"""Return the inverse hyperbolic cosine of an image in radians."""
return self.math('acosh')
[docs] def atanh(self):
"""Return the inverse hyperbolic tangent of an image in radians."""
return self.math('atanh')
[docs] def log(self):
"""Return the natural log of an image."""
return self.math('log')
[docs] def log10(self):
"""Return the log base 10 of an image."""
return self.math('log10')
[docs] def exp(self):
"""Return e ** pixel."""
return self.math('exp')
[docs] def exp10(self):
"""Return 10 ** pixel."""
return self.math('exp10')
[docs] def erode(self, mask):
"""Erode with a structuring element."""
return self.morph(mask, 'erode')
[docs] def dilate(self, mask):
"""Dilate with a structuring element."""
return self.morph(mask, 'dilate')
[docs] def fliphor(self):
"""Flip horizontally."""
return self.flip('horizontal')
[docs] def flipver(self):
"""Flip vertically."""
return self.flip('vertical')
[docs] def rot90(self):
"""Rotate 90 degrees clockwise."""
return self.rot('d90')
[docs] def rot180(self):
"""Rotate 180 degrees."""
return self.rot('d180')
[docs] def rot270(self):
"""Rotate 270 degrees clockwise."""
return self.rot('d270')
[docs] def hasalpha(self):
"""True if the image has an alpha channel."""
return vips_lib.vips_image_hasalpha(self.pointer)
[docs] def addalpha(self):
"""Add an alpha channel."""
if self.interpretation == 'grey16' or self.interpretation == 'rgb16':
max_alpha = 65535
else:
max_alpha = 255
return self.bandjoin(max_alpha)
# we need different _imageize rules for this operator ... we need to
# _imageize in1 and in2 to match each other first
[docs] @_add_doc('ifthenelse')
def ifthenelse(self, in1, in2, **kwargs):
for match_image in [in1, in2, self]:
if isinstance(match_image, pyvips.Image):
break
if not isinstance(in1, pyvips.Image):
in1 = Image._imageize(match_image, in1)
if not isinstance(in2, pyvips.Image):
in2 = Image._imageize(match_image, in2)
return pyvips.Operation.call('ifthenelse', self, in1, in2, **kwargs)
[docs] def scaleimage(self, **kwargs):
"""Scale an image to 0 - 255.
This is the libvips ``scale`` operation, renamed to avoid a clash with
the ``scale`` for convolution masks.
Keyword args:
exp (float): Exponent for log scale.
log (bool): Switch to turn on log scaling.
Returns:
A new :class:`Image`.
Raises:
:class:`.Error`
"""
return pyvips.Operation.call('scale', self, **kwargs)
__all__ = ['Image']