napari.layers.Image

class napari.layers.Image(data, *, rgb=None, colormap='gray', contrast_limits=None, gamma=1, interpolation='nearest', rendering='mip', iso_threshold=0.5, attenuation=0.05, name=None, metadata=None, scale=None, translate=None, rotate=None, shear=None, affine=None, opacity=1, blending='translucent', visible=True, multiscale=None, cache=True, experimental_slicing_plane=None, experimental_clipping_planes=None)[source]¶

Bases: napari.layers.image.image._ImageBase

Methods

`as_layer_data_tuple`()
`bind_key`(key[, func, overwrite])	Bind a key combination to a keymap.
`block_update_properties`()
`create`(data[, meta, layer_type])	Create layer from data of type layer_type.
`get_ray_intersections`(position, …[, world])	Get the start and end point for the ray extending from a point through the data bounding box.
`get_status`(position, *[, view_direction, …])	Status message of the data at a coordinate position.
`get_value`(position, *[, view_direction, …])	Value of the data at a position.
`refresh`([event])	Refresh all layer data based on current view slice.
`reset_contrast_limits`([mode])	Scale contrast limits to data range
`reset_contrast_limits_range`()	Scale contrast limits range to data type.
`save`(path[, plugin])	Save this layer to `path` with default (or specified) plugin.
`set_view_slice`()
`world_to_data`(position)	Convert from world coordinates to data coordinates.

Attributes

`affine`	Extra affine transform to go from physical to world coordinates.
`attenuation`	attenuation rate for attenuated_mip rendering.
`blending`	Determines how RGB and alpha values get mixed.
`class_keymap`
`colormap`	colormap for luminance images.
`colormaps`	names of available colormaps.
`contrast_limits`	Limits to use for the colormap.
`contrast_limits_range`	The current valid range of the contrast limits.
`cursor`	String identifying cursor displayed over canvas.
`cursor_size`	Size of cursor if custom.
`data`	Image data.
`data_level`	Current level of multiscale, or 0 if image.
`downsample_factors`	Downsample factors for each level of the multiscale.
`dtype`
`editable`	Whether the current layer data is editable from the viewer.
`experimental_clipping_planes`
`experimental_slicing_plane`
`extent`	Extent of layer in data and world coordinates.
`gamma`
`help`	displayed in status bar bottom right.
`interactive`	Determine if canvas pan/zoom interactivity is enabled.
`interpolation`	Return current interpolation mode.
`iso_threshold`	threshold for isosurface.
`level_shapes`	Shapes of each level of the multiscale or just of image.
`loaded`	Has the data for this layer been loaded yet.
`metadata`	Key/value map for user-stored data.
`name`	Unique name of the layer.
`ndim`	Number of dimensions in the data.
`opacity`	Opacity value between 0.0 and 1.0.
`rendering`	Return current rendering mode.
`rotate`	Rotation matrix in world coordinates.
`scale`	Anisotropy factors to scale data into world coordinates.
`shear`	Shear matrix in world coordinates.
`source`
`thumbnail`	Integer array of thumbnail for the layer
`translate`	Factors to shift the layer by in units of world coordinates.
`translate_grid`	Factors to shift the layer by.
`visible`	Whether the visual is currently being displayed.

Details

property affine¶

Extra affine transform to go from physical to world coordinates.

Type: napari.utils.transforms.Affine

property attenuation¶

attenuation rate for attenuated_mip rendering.

Type: float

bind_key(key, func=<object object>, *, overwrite=False)¶

Bind a key combination to a keymap.

Parameters

keymap (dict of str: callable) – Keymap to modify.
key (str or ..) – Key combination. ... acts as a wildcard if no key combinations can be matched in the keymap (this will overwrite all key combinations further down the lookup chain).
func (callable, None, or ..) – Callable to bind to the key combination. If None is passed, unbind instead. ... acts as a blocker, effectively unbinding the key combination for all keymaps further down the lookup chain.
overwrite (bool, keyword-only, optional) – Whether to overwrite the key combination if it already exists.

Returns

unbound – Callable unbound by this operation, if any.

Return type

callable or None

Notes

Key combinations are represented in the form [modifier-]key, e.g. a, Control-c, or Control-Alt-Delete. Valid modifiers are Control, Alt, Shift, and Meta.

Letters will always be read as upper-case. Due to the native implementation of the key system, Shift pressed in certain key combinations may yield inconsistent or unexpected results. Therefore, it is not recommended to use Shift with non-letter keys. On OSX, Control is swapped with Meta such that pressing Command reads as Control.

Special keys include Shift, Control, Alt, Meta, Up, Down, Left, Right, PageUp, PageDown, Insert, Delete, Home, End, Escape, Backspace, F1, F2, F3, F4, F5, F6, F7, F8, F9, F10, F11, F12, Space, Enter, and Tab

Functions take in only one argument: the parent that the function was bound to.

By default, all functions are assumed to work on key presses only, but can be denoted to work on release too by separating the function into two statements with the yield keyword:

@viewer.bind_key('h')
def hello_world(viewer):
    # on key press
    viewer.status = 'hello world!'

    yield

    # on key release
    viewer.status = 'goodbye world :('

To create a keymap that will block others, bind_key(..., ...)`.

property blending¶

Determines how RGB and alpha values get mixed.

Blending.OPAQUE: Allows for only the top layer to be visible and corresponds to depth_test=True, cull_face=False, blend=False.
Blending.TRANSLUCENT: Allows for multiple layers to be blended with different opacity and corresponds to depth_test=True, cull_face=False, blend=True, blend_func=(‘src_alpha’, ‘one_minus_src_alpha’).
Blending.ADDITIVE: Allows for multiple layers to be blended together with different colors and opacity. Useful for creating overlays. It corresponds to depth_test=False, cull_face=False, blend=True, blend_func=(‘src_alpha’, ‘one’).

Type: Blending mode

property colormap¶

colormap for luminance images.

Type: napari.utils.Colormap

property colormaps¶

names of available colormaps.

Type: tuple of str

property contrast_limits¶

Limits to use for the colormap.

Type: list of float

property contrast_limits_range¶: The current valid range of the contrast limits.

classmethod create(data, meta=None, layer_type=None)¶

Create layer from data of type layer_type.

Primarily intended for usage by reader plugin hooks and creating a layer from an unwrapped layer data tuple.

Parameters

data (Any) – Data in a format that is valid for the corresponding layer_type.
meta (dict, optional) – Dict of keyword arguments that will be passed to the corresponding layer constructor. If any keys in meta are not valid for the corresponding layer type, an exception will be raised.
layer_type (str) – Type of layer to add. Must be the (case insensitive) name of a Layer subclass. If not provided, the layer is assumed to be “image”, unless data.dtype is one of (np.int32, np.uint32, np.int64, np.uint64), in which case it is assumed to be “labels”.

Raises

ValueError – If layer_type is not one of the recognized layer types.
TypeError – If any keyword arguments in meta are unexpected for the corresponding add_* method for this layer_type.

Examples

A typical use case might be to upack a tuple of layer data with a specified layer_type.

>>> data = (
...     np.random.random((10, 2)) * 20,
...     {'face_color': 'blue'},
...     'points',
... )
>>> Layer.create(*data)

Return type: Layer

property cursor¶

String identifying cursor displayed over canvas.

Type: str

property cursor_size¶

Size of cursor if custom. None yields default size.

Type: int | None

property data¶

Image data.

Type: array

property data_level¶

Current level of multiscale, or 0 if image.

Type: int

property downsample_factors¶

Downsample factors for each level of the multiscale.

Type: list

property editable¶

Whether the current layer data is editable from the viewer.

Type: bool

property extent¶

Extent of layer in data and world coordinates.

Return type: Extent

get_ray_intersections(position, view_direction, dims_displayed, world=True)¶

Get the start and end point for the ray extending from a point through the data bounding box.

Parameters

position (List[float]) – the position of the point in nD coordinates. World vs. data is set by the world keyword argument.
view_direction (np.ndarray) – a unit vector giving the direction of the ray in nD coordinates. World vs. data is set by the world keyword argument.
dims_displayed (List[int]) – a list of the dimensions currently being displayed in the viewer.
world (bool) – True if the provided coordinates are in world coordinates. Default value is True.

Return type

Union[Tuple[ndarray, ndarray], Tuple[None, None]]

Returns

start_point (np.ndarray) – The point on the axis-aligned data bounding box that the cursor click intersects with. This is the point closest to the camera. The point is the full nD coordinates of the layer data. If the click does not intersect the axis-aligned data bounding box, None is returned.
end_point (np.ndarray) – The point on the axis-aligned data bounding box that the cursor click intersects with. This is the point farthest from the camera. The point is the full nD coordinates of the layer data. If the click does not intersect the axis-aligned data bounding box, None is returned.

get_status(position, *, view_direction=None, dims_displayed=None, world=False)¶

Status message of the data at a coordinate position.

Parameters

position (tuple) – Position in either data or world coordinates.
view_direction (Optional[np.ndarray]) – A unit vector giving the direction of the ray in nD world coordinates. The default value is None.
dims_displayed (Optional[List[int]]) – A list of the dimensions currently being displayed in the viewer. The default value is None.
world (bool) – If True the position is taken to be in world coordinates and converted into data coordinates. False by default.

Returns

msg – String containing a message that can be used as a status update.

Return type

string

get_value(position, *, view_direction=None, dims_displayed=None, world=False)¶

Value of the data at a position.

If the layer is not visible, return None.

Parameters

position (tuple) – Position in either data or world coordinates.
view_direction (Optional[np.ndarray]) – A unit vector giving the direction of the ray in nD world coordinates. The default value is None.
dims_displayed (Optional[List[int]]) – A list of the dimensions currently being displayed in the viewer. The default value is None.
world (bool) – If True the position is taken to be in world coordinates and converted into data coordinates. False by default.

Returns

value – Value of the data. If the layer is not visible return None.

Return type

tuple, None

property help¶

displayed in status bar bottom right.

Type: str

property interactive¶

Determine if canvas pan/zoom interactivity is enabled.

Type: bool

property interpolation¶

Return current interpolation mode.

Selects a preset interpolation mode in vispy that determines how volume is displayed. Makes use of the two Texture2D interpolation methods and the available interpolation methods defined in vispy/gloo/glsl/misc/spatial_filters.frag

Options include: ‘bessel’, ‘bicubic’, ‘bilinear’, ‘blackman’, ‘catrom’, ‘gaussian’, ‘hamming’, ‘hanning’, ‘hermite’, ‘kaiser’, ‘lanczos’, ‘mitchell’, ‘nearest’, ‘spline16’, ‘spline36’

Returns: The current interpolation mode
Return type: str

property iso_threshold¶

threshold for isosurface.

Type: float

property level_shapes¶

Shapes of each level of the multiscale or just of image.

Type: array

property loaded¶

Has the data for this layer been loaded yet.

With asynchronous loading the layer might exist but its data for the current slice has not been loaded.

property metadata¶

Key/value map for user-stored data.

Return type: dict

property name¶

Unique name of the layer.

Type: str

property ndim¶

Number of dimensions in the data.

Type: int

property opacity¶

Opacity value between 0.0 and 1.0.

Type: float

refresh(event=None)¶: Refresh all layer data based on current view slice.

property rendering¶

Return current rendering mode.

Selects a preset rendering mode in vispy that determines how volume is displayed. Options include:

translucent: voxel colors are blended along the view ray until
the result is opaque.
mip: maximum intensity projection. Cast a ray and display the
maximum value that was encountered.
minip: minimum intensity projection. Cast a ray and display the
minimum value that was encountered.
attenuated_mip: attenuated maximum intensity projection. Cast a
ray and attenuate values based on integral of encountered values, display the maximum value that was encountered after attenuation. This will make nearer objects appear more prominent.
additive: voxel colors are added along the view ray until
the result is saturated.
iso: isosurface. Cast a ray until a certain threshold is
encountered. At that location, lighning calculations are performed to give the visual appearance of a surface.
average: average intensity projection. Cast a ray and display the
average of values that were encountered.

Returns: The current rendering mode
Return type: str

reset_contrast_limits(mode=None)¶: Scale contrast limits to data range

reset_contrast_limits_range()¶

Scale contrast limits range to data type.

Currently, this only does something if the data type is an unsigned integer… otherwise it’s unclear what the full range should be.

property rotate¶

Rotation matrix in world coordinates.

Type: array

save(path, plugin=None)¶

Save this layer to path with default (or specified) plugin.

Parameters

path (str) – A filepath, directory, or URL to open. Extensions may be used to specify output format (provided a plugin is available for the requested format).
plugin (str, optional) – Name of the plugin to use for saving. If None then all plugins corresponding to appropriate hook specification will be looped through to find the first one that can save the data.

Returns

File paths of any files that were written.

Return type

list of str

property scale¶

Anisotropy factors to scale data into world coordinates.

Type: list

property shear¶

Shear matrix in world coordinates.

Type: array

property thumbnail¶

Integer array of thumbnail for the layer

Type: array

property translate¶

Factors to shift the layer by in units of world coordinates.

Type: list

property translate_grid¶

Factors to shift the layer by.

Type: list

property visible¶

Whether the visual is currently being displayed.

Type: bool

world_to_data(position)¶

Convert from world coordinates to data coordinates.

Parameters: position (tuple, list, 1D array) – Position in world coordinates. If longer then the number of dimensions of the layer, the later dimensions will be used.
Returns: Position in data coordinates.
Return type: tuple