Python API¶
This section includes information for using the pure Python API of
bob.io.image
.
-
bob.io.image.
load
(filename, extension) → image[source]¶ This function loads and image from the file with the specified
filename
. The type of the image will be determined based on theextension
parameter, which can have the following values:None
: The file name extension of thefilename
is used to determine the image type.'auto'
: The type of the image will be detected automatically, usingbob.io.image.get_correct_image_extension()
.'.xxx'
: The image type is determined by the given extension.- For a list of possible extensions, see
bob.io.base.extensions()
(only the image extensions are valid here).
Parameters:
filename
: str- The name of the image file to load.
extension
: str- [Default:
None
] If given, the given extension will determine the type of the image. Use'auto'
to automatically determine the extension (this might take slightly more time).
Returns
image
: 2D or 3D - The image read from the specified file.
numpy.ndarray
of typeuint8
-
bob.io.image.
read
(filename, extension=None)¶ load(filename, extension) -> image
This function loads and image from the file with the specified
filename
. The type of the image will be determined based on theextension
parameter, which can have the following values:None
: The file name extension of thefilename
is used to determine the image type.'auto'
: The type of the image will be detected automatically, usingbob.io.image.get_correct_image_extension()
.'.xxx'
: The image type is determined by the given extension.- For a list of possible extensions, see
bob.io.base.extensions()
(only the image extensions are valid here).
Parameters:
filename
: str- The name of the image file to load.
extension
: str- [Default:
None
] If given, the given extension will determine the type of the image. Use'auto'
to automatically determine the extension (this might take slightly more time).
Returns
image
: 2D or 3D - The image read from the specified file.
numpy.ndarray
of typeuint8
-
bob.io.image.
get_include_directories
() → includes[source]¶ Returns a list of include directories for dependent libraries, such as libjpeg, libtiff, ... This function is automatically used by
bob.extension.get_bob_libraries()
to retrieve the non-standard include directories that are required to use the C bindings of this library in dependent classes. You shouldn’t normally need to call this function by hand.Returns:
includes
: [str]- The list of non-standard include directories required to use the C bindings of this class. For now, only the directory for the HDF5 headers are returned.
-
bob.io.image.
get_macros
() → macros[source]¶ Returns a list of preprocessor macros, such as
(HAVE_LIBJPEG, 1)
. This function is automatically used bybob.extension.get_bob_libraries()
to retrieve the prerpocessor definitions that are required to use the C bindings of this library in dependent classes. You shouldn’t normally need to call this function by hand.Returns:
macros
: [str]- The list of preprocessor macros required to use the C bindings of this class.
-
bob.io.image.
get_correct_image_extension
(image_name) → extension¶ Estimates the image type and return a corresponding extension based on file content
This function loads the first bytes of the given image, and matches it with known magic numbers of image files. If a match is found, it returns the corresponding image extension (including the leading
'.'
that can be used, e.g., inbob.io.image.load()
.Parameters:
image_name
: strThe name (including path) of the image to checkReturns:
extension
: strThe extension of the image based on the file content
-
bob.io.image.
imshow
(img, cmap=None, **kwargs)¶ Plots the images that are returned by
bob.io.base.load()
Parameters: - img (numpy.ndarray) – A 2 or 3 dimensional array containing an image in
bob style: For a 2D array (grayscale image) should be
(y, x)
; For a 3D array (color image) should be(n, y, x)
. - cmap (matplotlib.colors.Colormap) – Colormap, optional, default:
None
. Ifcmap
isNone
andimg.ndim
is 2, defaults to ‘gray’.cmap
is ignored whenimg
has RGB(A) information. - kwargs – These are passed directly to
matplotlib.pyplot.imshow()
- img (numpy.ndarray) – A 2 or 3 dimensional array containing an image in
bob style: For a 2D array (grayscale image) should be
-
bob.io.image.
to_matplotlib
(img)¶ Returns a view of the image compatible with matplotlib.
Parameters: img (numpy.ndarray) – A 2 or 3 dimensional array containing an image in bob style: For a 2D array (grayscale image) should be (y, x)
; For a 3D array (color image) should be(n, y, x)
.Returns: - A view of the
img
compatible with matplotlib.pyplot.imshow()
.
Return type: numpy.ndarray - A view of the