LinearATM¶

class
menpofit.atm.
LinearATM
(template, shapes, group=None, holistic_features=<function no_op>, reference_shape=None, diagonal=None, scales=(0.5, 1.0), transform=<class 'menpofit.transform.thinsplatesplines.DifferentiableThinPlateSplines'>, max_shape_components=None, verbose=False, batch_size=None)[source]¶ Bases:
ATM
Class for training a multiscale Linear Active Template Model.
Parameters:  template (menpo.image.Image) – The template image.
 shapes (list of menpo.shape.PointCloud) – The list of training shapes.
 group (str or
None
, optional) – The landmark group of the template that will be used to train the ATM. IfNone
and the template only has a single landmark group, then that is the one that will be used.  holistic_features (closure or list of closure, optional) – The features that will be extracted from the training images. Note that the features are extracted before warping the images to the reference shape. If list, then it must define a feature function per scale. Please refer to menpo.feature for a list of potential features.
 reference_shape (menpo.shape.PointCloud or
None
, optional) – The reference shape that will be used for building the ATM. The purpose of the reference shape is to normalise the size of the training images. The normalization is performed by rescaling all the training images so that the scale of their ground truth shapes matches the scale of the reference shape. Note that the reference shape is rescaled with respect to the diagonal before performing the normalisation. IfNone
, then the mean shape will be used.  diagonal (int or
None
, optional) – This parameter is used to rescale the reference shape so that the diagonal of its bounding box matches the provided value. In other words, this parameter controls the size of the model at the highest scale. IfNone
, then the reference shape does not get rescaled.  scales (float or tuple of float, optional) – The scale value of each scale. They must provided in ascending order, i.e. from lowest to highest scale. If float, then a single scale is assumed.
 transform (subclass of
DL
andDX
, optional) – A differential warp transform object, e.g.DifferentiablePiecewiseAffine
orDifferentiableThinPlateSplines
.  max_shape_components (int, float, list of those or
None
, optional) – The number of shape components to keep. If int, then it sets the exact number of components. If float, then it defines the variance percentage that will be kept. If list, then it should define a value per scale. If a single number, then this will be applied to all scales. IfNone
, then all the components are kept. Note that the unused components will be permanently trimmed.  verbose (bool, optional) – If
True
, then the progress of building the ATM will be printed.  batch_size (int or
None
, optional) – If an int is provided, then the training is performed in an incremental fashion on image batches of size equal to the provided value. IfNone
, then the training is performed directly on the all the images.

build_fitter_interfaces
(sampling)[source]¶ Method that builds the correct LucasKanade fitting interface.
Parameters: sampling (list of int or ndarray or None
) – It defines a sampling mask per scale. If int, then it defines the subsampling step of the sampling mask. If ndarray, then it explicitly defines the sampling mask. IfNone
, then no subsampling is applied.Returns: fitter_interfaces (list) – The list of LucasKanade interface per scale.

increment
(template, shapes, group=None, shape_forgetting_factor=1.0, verbose=False, batch_size=None)¶ Method to increment the trained ATM with a new set of training shapes and a new template.
Parameters:  template (menpo.image.Image) – The template image.
 shapes (list of menpo.shape.PointCloud) – The list of training shapes.
 group (str or
None
, optional) – The landmark group of the template that will be used to train the ATM. IfNone
and the template only has a single landmark group, then that is the one that will be used.  shape_forgetting_factor (
[0.0, 1.0]
float, optional) – Forgetting factor that weights the relative contribution of new samples vs old samples for the shape model. If1.0
, all samples are weighted equally and, hence, the result is the exact same as performing batch PCA on the concatenated list of old and new simples. If<1.0
, more emphasis is put on the new samples.  verbose (bool, optional) – If
True
, then the progress of building the ATM will be printed.  batch_size (int or
None
, optional) – If an int is provided, then the training is performed in an incremental fashion on image batches of size equal to the provided value. IfNone
, then the training is performed directly on the all the images.

instance
(shape_weights=None, scale_index=1)¶ Generates a novel ATM instance given a set of shape weights. If no weights are provided, the mean ATM instance is returned.
Parameters:  shape_weights (
(n_weights,)
ndarray or list orNone
, optional) – The weights of the shape model that will be used to create a novel shape instance. IfNone
, the weights are assumed to be zero, thus the mean shape is used.  scale_index (int, optional) – The scale to be used.
Returns: image (menpo.image.Image) – The ATM instance.
 shape_weights (

random_instance
(scale_index=1)¶ Generates a random instance of the ATM.
Parameters: scale_index (int, optional) – The scale to be used. Returns: image (menpo.image.Image) – The ATM instance.

view_shape_models_widget
(n_parameters=5, parameters_bounds=(3.0, 3.0), mode='multiple', figure_size=(7, 7))¶ Visualizes the shape models of the ATM object using an interactive widget.
Parameters:  n_parameters (int or list of int or
None
, optional) – The number of shape principal components to be used for the parameters sliders. If int, then the number of sliders per scale is the minimum between n_parameters and the number of active components per scale. If list of int, then a number of sliders is defined per scale. IfNone
, all the active components per scale will have a slider.  parameters_bounds (
(float, float)
, optional) – The minimum and maximum bounds, in std units, for the sliders.  mode ({
single
,multiple
}, optional) – If'single'
, only a single slider is constructed along with a drop down menu. If'multiple'
, a slider is constructed for each parameter.  figure_size ((int, int), optional) – The size of the rendered figure.
 n_parameters (int or list of int or

n_scales
¶ Returns the number of scales.
Type: int