import os
import pathlib
import warnings
from collections.abc import Callable
import numpy as np
import numpy.typing as npt
from .. import colormap
from .. import debug as debug
from .. import functions as fn
from .. import functions_qimage
from .. import getConfigOption
from ..Point import Point
from ..Qt import QtCore, QtGui, QtWidgets
from ..util.cupy_helper import getCupy
from .GraphicsObject import GraphicsObject
translate = QtCore.QCoreApplication.translate
__all__ = ['ImageItem']
[docs]
class ImageItem(GraphicsObject):
"""
Graphics object used to display image data.
ImageItem can render images with 1, 3 or 4 channels, use lookup tables to apply
false colors to images, and users can either set levels limits, or rely on
the auto-sampling.
Performance can vary wildly based on the attributes of the inputs provided, see
:ref:`performance <ImageItem_performance>` for guidance if performance is an
important factor.
There is optional `numba` and `cupy` support.
**Bases:** :class:`pyqtgraph.GraphicsObject`
Parameters
----------
image : np.ndarray or None, default None
Image data.
**kargs : dict, optional
Arguments directed to `setImage` and `setOpts`, refer to each method for
documentation for possible arguments.
Signals
-------
sigImageChanged: :class:`Signal`
Emitted when the image is changed.
sigRemoveRequested: :class:`Signal`
Emitted when there is a request to remove the image. Signal emits the instance
of the :class:`~pyqtgraph.ImageItem` whose removal is requested.
See Also
--------
setImage :
For descriptions of available keyword arguments.
setOpts :
For information on supported formats.
"""
sigImageChanged = QtCore.Signal()
sigRemoveRequested = QtCore.Signal(object)
def __init__(self, image: np.ndarray | None=None, **kargs):
super().__init__()
self.menu = None
self.image = None ## original image data
self.qimage = None ## rendered image for display
self.paintMode = None
self.levels = None ## [min, max] or [[redMin, redMax], ...]
self.lut = None
self.autoDownsample = False
self._nanPolicy = 'propagate'
self._colorMap = None # This is only set if a color map is assigned directly
self._lastDownsample = (1, 1)
self._processingBuffer = None
self._displayBuffer = None
self._renderRequired = True
self._unrenderable = False
self._xp = None # either numpy or cupy, to match the image data
self._defferedLevels = None
self._imageHasNans = None # None : not yet known
self._imageNanLocations = None
self._defaultAutoLevels = True
self.axisOrder = getConfigOption('imageAxisOrder')
self._dataTransform = self._inverseDataTransform = QtGui.QTransform()
self._update_data_transforms( self.axisOrder ) # install initial transforms
self.drawKernel = None
self.border = None
self.removable = False
if image is not None:
self.setImage(image, **kargs)
else:
self.setOpts(**kargs)
[docs]
def setCompositionMode(self, mode: QtGui.QPainter.CompositionMode):
"""
Change the composition mode of the item, useful when overlaying multiple items.
Parameters
----------
mode : :class:`QPainter.CompositionMode <QPainter.CompositionMode>`
Composition of the item, often used when overlaying items. Common
options include:
* `QPainter.CompositionMode.CompositionMode_SourceOver`
Image replaces the background if it is opaque. Otherwise, it uses the
alpha channel to blend the image with the background, default.
* `QPainter.CompositionMode.CompositionMode_Overlay` Image color is
mixed with the background color to reflect the lightness or darkness of
the background.
* `QPainter.CompositionMode.CompositionMode_Plus` Both the alpha and
color of the image and background pixels are added together.
* `QPainter.CompositionMode.CompositionMode_Plus` The output is the
image color multiplied by the background.
See :class:`QPainter.CompositionMode <QPainter.CompositionMode>` in the Qt
documentation for more options and details.
See Also
--------
:class:`QPainter.CompositionMode <QPainter.CompositionMode>` :
Details all the possible composition mode options accepted.
"""
self.paintMode = mode
self.update()
[docs]
def setBorder(self, b):
"""
Define the color of the border drawn around the image.
Parameters
----------
b : color_like
Accepts all arguments supported by :func:`~pyqtgraph.mkPen`.
"""
self.border = fn.mkPen(b)
self.update()
def width(self) -> int | None:
if self.image is None:
return None
axis = 0 if self.axisOrder == 'col-major' else 1
return self.image.shape[axis]
def height(self) -> int | None:
if self.image is None:
return None
axis = 1 if self.axisOrder == 'col-major' else 0
return self.image.shape[axis]
def channels(self) -> int | None:
if self.image is None:
return None
return self.image.shape[2] if self.image.ndim == 3 else 1
def boundingRect(self) -> QtCore.QRectF:
if self.image is None:
return QtCore.QRectF(0., 0., 0., 0.)
if (width := self.width()) is None:
width = 0.
if (height := self.height()) is None:
height = 0.
return QtCore.QRectF(0., 0., float(width), float(height))
[docs]
def setAutoLevels(self, bState: bool):
"""
Controls whether automatic image scaling takes place for this ImageItem,
if not otherwise overridden by ``autoLevels`` or ``levels`` keyword
arguments in a call to :func:`~pyqtgraph.ImageItem.setImage`.
"""
self._defaultAutoLevels = bState
[docs]
def setLevels(self, levels: npt.ArrayLike | None, update: bool=True):
"""
Set image scaling levels.
Calling this method, even with ``levels=None`` will disable auto leveling
which is equivalent to :meth:`setImage` with ``autoLevels=False``.
Parameters
----------
levels : array_like or None
Sets the numerical values that correspond to the limits of the color range.
* ``[blackLevel, whiteLevel]``
sets black and white levels for monochrome data and can be used with a
lookup table.
* ``[[minR, maxR], [minG, maxG], [minB, maxB]]``
sets individual scaling for RGB values. Not compatible with lookup
tables.
* ``None``
Disables the application of levels, but setting to ``None`` prevents
the auto-levels mechanism from sampling the image. Not compatible with
images that use floating point dtypes.
update : bool, default True
Update the image immediately to reflect the new levels.
See Also
--------
pyqtgraph.functions.makeARGB
For more details on how levels are applied.
"""
if self._xp is None:
self.levels = levels
self._defferedLevels = levels
return
if levels is not None:
levels = self._xp.asarray(levels)
self.levels = levels
if update:
self.updateImage()
[docs]
def getLevels(self) -> np.ndarray | None:
"""
Return the array representing the current level settings.
See :meth:`setLevels`. When `autoLevels` is active, the format is
``[blackLevel, whiteLevel]``.
Returns
-------
np.ndarray or None
The value that the levels are set to.
"""
return self.levels
[docs]
def setColorMap(self, colorMap: colormap.ColorMap | str):
"""
Set a color map for false color display of a monochrome image.
Parameters
----------
colorMap : :class:`~pyqtgraph.ColorMap` or `str`
A string argument will be passed to
:func:`colormap.get() <pyqtgraph.colormap.get>`.
Raises
------
TypeError
Raised when `colorMap` is not of type `str` or :class:`~pyqtgraph.ColorMap`.
"""
if isinstance(colorMap, colormap.ColorMap):
self._colorMap = colorMap
elif isinstance(colorMap, str):
self._colorMap = colormap.get(colorMap)
else:
raise TypeError("'colorMap' argument must be ColorMap or string")
self.setLookupTable( self._colorMap.getLookupTable(nPts=256) )
[docs]
def getColorMap(self) -> colormap.ColorMap | None:
"""
Retrieve the :class:`~pyqtgraph.ColorMap` object currently used.
Returns
-------
ColorMap or None
The assigned :class:`~pyqtgraph.ColorMap`, or `None` if not available.
"""
return self._colorMap
[docs]
def setLookupTable(self, lut: npt.ArrayLike | Callable, update: bool=True):
"""
Set lookup table `lut` to use for false color display of a monochrome image.
Ordinarily, this table is supplied by a :class:`~pyqtgraph.HistogramLUTItem`,
:class:`~pyqtgraph.GradientEditorItem` or :class:`~pyqtgraph.ColorBarItem`.
Parameters
----------
lut : array_like or callable
If `lut` is an np.ndarray, ensure the dtype is `np.uint8`. Alternatively
can be a callable that accepts the current image as an argument and
returns the lookup table to use. Support for callable will be removed
in a future version of pyqtgraph.
update : bool, default True
Update the intermediate image.
See Also
--------
:func:`pyqtgraph.functions.makeARGB`
See this function for more information on how this is used.
:meth:`ColorMap.getLookupTable <pyqtgraph.ColorMap.getLookupTable>`
Can construct a lookup table from a :class:`~pyqtgraph.ColorMap` object.
Notes
-----
For performance reasons, if not passing a callable, every effort should be made
to keep the number of entries to `<= 256`.
"""
if lut is not self.lut:
if self._xp is not None:
lut = self._ensure_proper_substrate(lut, self._xp)
self.lut = lut
if update:
self.updateImage()
@staticmethod
def _ensure_proper_substrate(data: Callable | npt.ArrayLike, substrate) -> np.ndarray:
if data is None or isinstance(data, (Callable, substrate.ndarray)):
return data
cupy = getCupy()
if substrate == cupy and not isinstance(data, cupy.ndarray):
data = cupy.asarray(data)
elif substrate == np:
if cupy is not None and isinstance(data, cupy.ndarray):
data = data.get()
else:
data = np.asarray(data)
return data
[docs]
def setAutoDownsample(self, active: bool=True):
"""
Control automatic downsampling for this ImageItem.
Parameters
----------
active : bool, default True
If `active` is ``True``, the image is automatically downsampled to match
the screen resolution. This improves performance for large images and
reduces aliasing. If `autoDownsample` is not specified, then ImageItem will
choose whether to downsample the image based on its size. ``False``
disables automatic downsampling.
"""
self.autoDownsample = active
self._renderRequired = True
self.update()
[docs]
def nanPolicy(self) -> str:
"""
Retrieve the string representing the current NaN policy.
See :meth:setNanPolicy.
Returns
-------
{ 'propagate', 'omit' }
The NaN policy that this ImageItem uses during downsampling.
"""
return self._nanPolicy
[docs]
def setNanPolicy(self, nanPolicy: str):
"""
Control how NaN values are handled during downsampling for this ImageItem.
Parameters
----------
nanPolicy : { 'propagate', 'omit' }
If 'nanPolicy' is 'ignore', NaNs are automatically ignored during
downsampling, at the expense of performance. If 'nanPolicy' is 'propagate',
NaNs are kept during downsampling. Unless a different policy was specified,
a new ImageItem is created with ``nanPolicy='propagate'``.
"""
if nanPolicy not in ['propagate', 'omit']:
raise ValueError(f"{nanPolicy=} must be one of {'propagate', 'omit'}")
self._nanPolicy = nanPolicy
self._renderRequired = True
self.update()
[docs]
def setOpts(self, update: bool=True, **kwargs):
"""
Set display and processing options for this ImageItem.
:class:`~pyqtgraph.ImageItem` and :meth:`setImage` support all keyword
arguments listed here.
Parameters
----------
update : bool, default True
Controls if image immediately updates to reflect the new options.
**kwargs : dict, optional
Extra arguments that are directed to the respective methods. Expected
keys include:
* `autoDownsample` whose value is directed to :meth:`setAutoDownsample`
* `nanPolicy` whose value is directed to :meth:`setNanPolicy`
* `axisOrder`, which needs to be one of {'row-major', 'col-major'},
determines the relationship between the numpy axis and visual axis
of the data.
* `border`, whose value is directed to :meth:`setBorder`
* `colorMap`, whose value is directed to :meth:`setColorMap`
* `compositionMode`, whose value is directed to :meth:`setCompositionMode`
* `levels` whose value is directed to :meth:`setLevels`
* `lut`, whose value is directed to :meth:`setLookupTable`
* `opacify` whose value is directed to
:meth:`QGraphicsItem.setOpacity <QGraphicsItem.setOpacity>`
* `rect` whose value is directed to :meth:`setRect`
* `removable` boolean, determines if the context menu is available
See Also
--------
:meth:`setAutoDownsample`
Accepts the value of ``kwargs['autoDownsample']``.
:meth:`setAutoLevels`
Accepts the value of ``kwargs['autoLevels']``.
:meth:`setNanPolicy`
Accepts the value of ``kwargs['nanPolicy']``.
:meth:`setBorder`
Accepts the value of ``kwargs['border']``.
:meth:`setColorMap`
Accepts the value of ``kwargs['colorMap']``.
:meth:`setCompositionMode`
Accepts the value of ``kwargs['compositionMode']``.
:meth:`setImage`
Accepts the value of ``kwargs['image']``.
:meth:`setLevels`
Accepts the value of ``kwargs['levels']``.
:meth:`setLookupTable`
Accepts the value of ``kwargs['lut']``.
:meth:`QGraphicsItem.setOpacity <QGraphicsItem.setOpacity>`
Accepts the value of ``kwargs['opacity']``.
:meth:`setRect`
Accepts the value of ``kwargs['rect']``.
"""
if 'axisOrder' in kwargs:
val = kwargs['axisOrder']
if val not in ('row-major', 'col-major'):
raise ValueError("axisOrder must be either 'row-major' or 'col-major'")
self.axisOrder = val
self._update_data_transforms(self.axisOrder) # update cached transforms
if 'colorMap' in kwargs:
self.setColorMap(kwargs['colorMap'])
if 'lut' in kwargs:
self.setLookupTable(kwargs['lut'], update=update)
if 'levels' in kwargs:
self.setLevels(kwargs['levels'], update=update)
#if 'clipLevel' in kargs:
#self.setClipLevel(kargs['clipLevel'])
if 'opacity' in kwargs:
self.setOpacity(kwargs['opacity'])
if 'compositionMode' in kwargs:
self.setCompositionMode(kwargs['compositionMode'])
if 'border' in kwargs:
self.setBorder(kwargs['border'])
if 'removable' in kwargs:
self.removable = kwargs['removable']
self.menu = None
if 'autoDownsample' in kwargs:
self.setAutoDownsample(kwargs['autoDownsample'])
if 'autoLevels' in kwargs:
self.setAutoLevels(kwargs['autoLevels'])
if 'nanPolicy' in kwargs:
self.setNanPolicy(kwargs['nanPolicy'])
if 'rect' in kwargs:
self.setRect(kwargs['rect'])
if update:
self.update()
[docs]
def setRect(self, *args):
"""
Set view rectangle for the :class:`~pyqtgraph.ImageItem` to occupy.
In addition to accepting a :class:`QRectF`, you can pass the numerical values
representing the `x, y, w, h`, where `x, y` represent the x, y coordinates
of the top left corner, and `w` and `h` represent the width and height
respectively.
Parameters
----------
*args : tuple
Contains one of :class:`QRectF`, :class:`QRect`, or arguments that can be
used to construct :class:`QRectF`.
See Also
--------
:class:`QRectF` :
See constructor methods for allowable `*args`.
Notes
-----
This method cannot be used before an image is assigned. See the
:ref:`examples <ImageItem_examples>` for how to manually set transformations.
"""
if not args:
# reset scaling and rotation when called without argument
self.resetTransform()
return
if isinstance(args[0], (QtCore.QRectF, QtCore.QRect)):
rect = args[0] # use QRectF or QRect directly
else:
if hasattr(args[0],'__len__'):
args = args[0] # promote tuple or list of values
# QRectF(x,y,w,h), but also accepts other initializers
rect = QtCore.QRectF( *args )
tr = QtGui.QTransform()
tr.translate(rect.left(), rect.top())
if (width := self.width()) is None:
width = 1.
if (height := self.height()) is None:
height = 1.
tr.scale(rect.width() / width, rect.height() / height)
self.setTransform(tr)
[docs]
def clear(self):
"""
Clear the assigned image.
"""
self.image = None
self.prepareGeometryChange()
self.informViewBoundsChanged()
self.update()
def _buildQImageBuffer(self, shape: tuple[int, int, int]):
self._displayBuffer = np.empty(shape[:2] + (4,), dtype=np.ubyte)
if self._xp == getCupy():
self._processingBuffer = self._xp.empty(
shape[:2] + (4,),
dtype=self._xp.ubyte
)
else:
self._processingBuffer = self._displayBuffer
self.qimage = None
[docs]
def setImage(
self,
image: np.ndarray | None=None,
autoLevels: bool | None=None,
levelSamples: int = 65536,
**kwargs
):
"""
Update the image displayed by this ImageItem.
All keywords supported by :meth:`setOpts` are also allowed here.
Parameters
----------
image : np.ndarray or None, default None
Image data given as NumPy array with an integer or floating point dtype of
any bit depth. A 2-dimensional array describes single-valued
(monochromatic) data. A 3-dimensional array is used to give individual
color components. The third dimension must be of length 3 (RGB) or 4
(RGBA). ``np.nan`` values are treated as transparent pixels.
autoLevels : bool or None, default None
If ``True``, ImageItem will automatically select levels based on the maximum
and minimum values encountered in the data. For performance reasons, this
search sub-samples the images and may miss individual bright or dark points
in the data set. If ``False``, the search will be omitted. If ``None``, the
value set by :func:`~pyqtgraph.ImageItem.setOpts` is used, unless a ``levels``
keyword argument is given, which implies `False`.
levelSamples : int, default 65536
Only used when ``autoLevels is None``. When determining minimum and
maximum values, ImageItem only inspects a subset of pixels no larger than
this number. Setting this larger than the total number of pixels considers
all values. See `quickMinMax`.
**kwargs : dict, optional
Extra arguments that are passed to `setOpts`.
See Also
--------
quickMinMax
See this method for how levelSamples value is utilized.
:func:`pyqtgraph.functions.makeARGB`
See this function for how image data is modified prior to rendering.
Notes
-----
For backward compatibility, image data is assumed to be in column-major order
(column, row) by default. However, most data is stored in row-major order
(row, column). It can either be transposed before assignment
.. code-block:: python
imageitem.setImage(imagedata.T)
or the interpretation of the data can be changed locally through the
`axisOrder` keyword or by changing the `imageAxisOrder`
:ref:`global configuration option <apiref_config>`.
"""
profile = debug.Profiler()
gotNewData = False
if image is None:
if self.image is None:
return
else:
old_xp = self._xp
cp = getCupy()
self._xp = cp.get_array_module(image) if cp else np
gotNewData = True
processingSubstrateChanged = old_xp != self._xp
if processingSubstrateChanged:
self._processingBuffer = None
shapeChanged = (
processingSubstrateChanged or
self.image is None or
image.shape != self.image.shape
)
image = image.view()
self.image = image
self._imageHasNans = None
self._imageNanLocations = None
if 'autoDownsample' not in kwargs and (
self.image.shape[0] > 2**15-1 or self.image.shape[1] > 2**15-1
):
kwargs['autoDownsample'] = True
if shapeChanged:
self.prepareGeometryChange()
self.informViewBoundsChanged()
profile()
if autoLevels is None:
autoLevels = False if 'levels' in kwargs else self._defaultAutoLevels
if autoLevels:
mn, mx = self.quickMinMax( targetSize=levelSamples )
# mn and mx can still be NaN if the data is all-NaN
if mn == mx or self._xp.isnan(mn) or self._xp.isnan(mx):
mn = 0
mx = 255
kwargs['levels'] = self._xp.asarray((mn,mx))
profile()
self.setOpts(update=False, **kwargs)
profile()
self._renderRequired = True
self.update()
profile()
if gotNewData:
self.sigImageChanged.emit()
if self._defferedLevels is not None:
levels = self._defferedLevels
self._defferedLevels = None
self.setLevels((levels))
def _update_data_transforms(self, axisOrder: str='col-major'):
"""
Set up the transforms needed to map between input array and display.
Parameters
----------
axisOrder : { 'col-major', 'row-major' }
The axis order to update the data transformation to.
"""
self._dataTransform = QtGui.QTransform()
self._inverseDataTransform = QtGui.QTransform()
if self.axisOrder == 'row-major': # transpose both
self._dataTransform.scale(1, -1)
self._dataTransform.rotate(-90)
self._inverseDataTransform.scale(1, -1)
self._inverseDataTransform.rotate(-90)
def dataTransform(self):
"""
Get the transform mapping image array to local coordinate system.
This transform corrects for the transposition that occurs when image data is
interpreted in row-major order.
:meta private:
Returns
-------
:class:`QTransform`
The transform that is used for mapping.
"""
# Might eventually need to account for downsampling / clipping here
# transforms are updated in setOpts call.
return self._dataTransform
def inverseDataTransform(self) -> QtGui.QTransform:
"""
Get the transform mapping local coordinate system to image array.
:meta private:
Returns
-------
:class:`QTransform`
The transform that is used for mapping.
See Also
--------
dataTransform
See dataTransform() for more information.
"""
# transforms are updated in setOpts call.
return self._inverseDataTransform
def mapToData(self, obj):
return self._inverseDataTransform.map(obj)
def mapFromData(self, obj):
return self._dataTransform.map(obj)
[docs]
def quickMinMax(self, targetSize: int=1_000_000) -> tuple[float, float]:
"""
Estimate the min and max values of the image data by sub-sampling.
Sampling is performed at regular strides chosen to evaluate a number of
samples equal to or less than `targetSize`. Returns the estimated min and max
values of the image data.
Parameters
----------
targetSize : int, default 1_000_000
The number of pixels to downsample the image to.
Returns
-------
float, float
Estimated minimum and maximum values of the image data.
"""
data = self.image
if data is None:
# image hasn't been set yet
return 0., 0.
targetSize = max(targetSize, 2) # keep at least 2 pixels
while True:
h, w = data.shape[:2]
if h * w <= targetSize: break
data = data[::2, ::] if h > w else data[::, ::2]
return self._xp.nanmin(data), self._xp.nanmax(data)
def updateImage(self, *args, **kargs):
defaults = {
'autoLevels': False,
} | kargs
return self.setImage(*args, **defaults)
def render(self):
# Convert data to QImage for display.
self._unrenderable = True
if self.image is None or self.image.size == 0:
return
# Request a lookup table if this image has only one channel
if self.image.ndim == 2 or self.image.shape[2] == 1:
self.lut = self._ensure_proper_substrate(self.lut, self._xp)
if isinstance(self.lut, Callable):
lut = self._ensure_proper_substrate(
self.lut(self.image, 256),
self._xp
)
else:
lut = self.lut
else:
lut = None
if self._imageHasNans is None:
# awkward, but fastest numpy native nan evaluation
self._imageHasNans = (
self.image.dtype.kind == 'f' and
self._xp.isnan(self.image.min())
)
self._imageNanLocations = None
image = self.image
if self.autoDownsample:
xds, yds = self._computeDownsampleFactors()
if xds is None:
return
axes = [1, 0] if self.axisOrder == 'row-major' else [0, 1]
nan_policy = self._nanPolicy if self._imageHasNans else 'propagate'
image = fn.downsample(image, xds, axis=axes[0], nanPolicy=nan_policy)
image = fn.downsample(image, yds, axis=axes[1], nanPolicy=nan_policy)
self._lastDownsample = (xds, yds)
# changes in view transform cause changes in downsampling factors,
# which invalidates any previously calculated nan locations
self._imageNanLocations = None
# Check if downsampling reduced the image size to zero due to inf values.
if image.size == 0:
return
# Convert single-channel image to 2D array
if image.ndim == 3 and image.shape[-1] == 1:
image = image[..., 0]
# Assume images are in column-major order for backward compatibility
# (most images are in row-major order)
if self.axisOrder == 'col-major':
image = image.swapaxes(0, 1)
levels = self.levels
qimage = None
if lut is not None and lut.dtype != self._xp.uint8:
# try_make_image() assumes that lut is of type uint8.
# It is considered a usage error if that is not the case.
# However, the makeARGB() code-path has previously allowed such
# a usage to work. Rather than fail outright, we delegate this
# case to makeARGB().
warnings.warn(
("Using non-uint8 LUTs is an undocumented accidental feature and may "
"be removed at some point in the future. Please open an issue if you "
"instead believe this to be worthy of protected inclusion in "
"pyqtgraph."),
DeprecationWarning,
stacklevel=2
)
elif not self._imageHasNans:
qimage = functions_qimage.try_make_qimage(image, levels=levels, lut=lut)
elif image.ndim in (2, 3):
# float images with nans
if self._imageNanLocations is None:
# the number of nans is expected to be small
nanmask = self._xp.isnan(image)
if nanmask.ndim == 3:
nanmask = nanmask.any(axis=2)
self._imageNanLocations = nanmask.nonzero()
qimage = functions_qimage.try_make_qimage(
image,
levels=levels,
lut=lut,
transparentLocations=self._imageNanLocations
)
if qimage is not None:
self._processingBuffer = None
self._displayBuffer = None
self.qimage = qimage
self._renderRequired = False
self._unrenderable = False
return
if (
self._processingBuffer is None or
self._processingBuffer.shape[:2] != image.shape[:2]
):
self._buildQImageBuffer(image.shape)
fn.makeARGB(image, lut=lut, levels=levels, output=self._processingBuffer)
if self._xp == getCupy():
self._processingBuffer.get(out=self._displayBuffer)
self.qimage = fn.ndarray_to_qimage(
self._displayBuffer,
QtGui.QImage.Format.Format_ARGB32
)
self._renderRequired = False
self._unrenderable = False
def paint(self, painter, *args):
profile = debug.Profiler()
if self.image is None:
return
if self._renderRequired:
self.render()
if self._unrenderable:
return
profile('render QImage')
if self.paintMode is not None:
painter.setCompositionMode(self.paintMode)
profile('set comp mode')
shape = (
self.image.shape[:2]
if self.axisOrder == 'col-major'
else self.image.shape[:2][::-1]
)
painter.drawImage(QtCore.QRectF(0,0,*shape), self.qimage)
profile('p.drawImage')
if self.border is not None:
painter.setPen(self.border)
painter.drawRect(self.boundingRect())
[docs]
def save(self, fileName: str | pathlib.Path, *args) -> None:
"""
Save this image to file.
Note that this saves the visible image, after scale/color changes, not the
original data.
Parameters
----------
fileName : os.PathLike
File path to save the image data to.
*args : tuple
Arguments that are passed to :meth:`QImage.save <QImage.save>`.
See Also
--------
:meth:`QImage.save <QImage.save>` :
``*args`` is relayed to this method.
"""
if self.qimage is None:
return None
if self._renderRequired:
self.render()
self.qimage.save(os.fsdecode(fileName), *args)
[docs]
def getHistogram(
self,
bins: str | int='auto',
step: str | np.generic='auto',
perChannel: bool=False,
targetImageSize: int=200,
**kwargs
) -> list[tuple[np.ndarray, np.ndarray]] | tuple[np.ndarray, np.ndarray] | tuple[None, None]:
"""
Generate arrays containing the histogram values.
Similar to :func:`numpy.histogram`
Parameters
----------
bins : int or str, default 'auto'
The `bins` argument and any extra keyword arguments are passed to
:func:`numpy.histogram()`. If ``bins == 'auto'``, a bin number is
automatically chosen based on the image characteristics.
step : int or str, default 'auto'
The `step` argument causes pixels to be skipped when computing the
histogram to save time. If `step` is 'auto', then a step is chosen such
that the analyzed data has dimensions approximating `targetImageSize`
for each axis.
perChannel : bool, default False
If ``True``, then a histogram is computed for each channel, and the output
is a list of the results.
targetImageSize : int, default 200
This parameter is used if ``step == 'auto'``, If so, the `step` size is
calculated by ``step = ceil(image.shape[0] / targetImageSize)``.
**kwargs : dict, optional
Dictionary of arguments passed to :func:`numpy.histogram()`.
Returns
-------
numpy.ndarray, numpy.ndarray or None, None or list of tuple of numpy.ndarray, numpy.ndarray
Returns `x` and `y` arrays containing the histogram values for the current
image. For an explanation of the return format, see
:func:`numpy.histogram()`.
Returns ``[(numpy.ndarray, numpy.ndarray),...]`` if ``perChannel=True``, one
element per channel.
Returns ``(None, None)`` is there is no image, or image size is 0.
Warns
-----
RuntimeWarning
Emits when `targetHistogramSize` argument is passed in, which does nothing.
See Also
--------
numpy.histogram :
Describes return format in greater detail.
numpy.histogram_bin_edges:
Details the different string values accepted as the `bins` parameter.
"""
if 'targetHistogramSize' in kwargs:
warnings.warn(
"'targetHistogramSize' option is not used",
RuntimeWarning,
stacklevel=2
)
# This method is also used when automatically computing levels.
if self.image is None or self.image.size == 0:
return None, None
if step == 'auto':
step = (max(1, int(self._xp.ceil(self.image.shape[0] / targetImageSize))),
max(1, int(self._xp.ceil(self.image.shape[1] / targetImageSize))))
if self._xp.isscalar(step):
step = (step, step)
stepData = self.image[::step[0], ::step[1]]
if isinstance(bins, str) and bins == 'auto':
mn = self._xp.nanmin(stepData).item()
mx = self._xp.nanmax(stepData).item()
if mx == mn:
# degenerate image, arange will fail
mx += 1
if self._xp.isnan(mn) or self._xp.isnan(mx):
# the data are all-nan
return None, None
if stepData.dtype.kind in "ui":
# For integer data, we select the bins carefully to avoid aliasing
step = int(self._xp.ceil((mx - mn) / 500.))
bins = []
if step > 0.0:
bins = self._xp.arange(mn, mx + 1.01 * step, step, dtype=int)
else:
# for float data, let numpy select the bins.
bins = self._xp.linspace(mn, mx, 500)
if len(bins) == 0:
bins = self._xp.asarray((mn, mx))
kwargs['bins'] = bins
cp = getCupy()
if perChannel:
hist = []
for i in range(stepData.shape[-1]):
stepChan = stepData[..., i]
stepChan = stepChan[self._xp.isfinite(stepChan)]
h = self._xp.histogram(stepChan, **kwargs)
if cp:
hist.append((cp.asnumpy(h[1][:-1]), cp.asnumpy(h[0])))
else:
hist.append((h[1][:-1], h[0]))
return hist
else:
stepData = stepData[self._xp.isfinite(stepData)]
hist = self._xp.histogram(stepData, **kwargs)
if cp:
return cp.asnumpy(hist[1][:-1]), cp.asnumpy(hist[0])
else:
return hist[1][:-1], hist[0]
[docs]
def setPxMode(self, b: bool):
"""
Set whether item ignores transformations and draws directly to screen pixels.
Parameters
----------
b : bool
If ``True``, the item will not inherit any scale or rotation
transformations from its parent items, but its position will be transformed
as usual.
See Also
--------
:class:`QGraphicsItem.GraphicsItemFlag <QGraphicsItem.GraphicsItemFlag>` :
Read the description of `ItemIgnoresTransformations` for more information.
"""
self.setFlag(
QtWidgets.QGraphicsItem.GraphicsItemFlag.ItemIgnoresTransformations,
b
)
def setScaledMode(self):
self.setPxMode(False)
def getPixmap(self) -> QtGui.QPixmap | None:
if self._renderRequired:
self.render()
if self._unrenderable:
return None
if self.qimage is None:
return QtGui.QPixmap()
return QtGui.QPixmap.fromImage(self.qimage)
[docs]
def pixelSize(self) -> tuple[float, float]:
"""
Get the `x` and `y` size of each pixel in the view coordinate system.
Returns
-------
float, float
The `x` and `y` size of each pixel in scene space.
"""
br = self.sceneBoundingRect()
if self.image is None:
return 1.,1.
if (width := self.width()) is None:
width = 0.
if (height := self.height()) is None:
height = 0.
return br.width() / width, br.height() / height
def viewTransformChanged(self):
if self.autoDownsample:
xds, yds = self._computeDownsampleFactors()
if xds is None:
self._renderRequired = True
self._unrenderable = True
return
if (xds, yds) != self._lastDownsample:
self._renderRequired = True
self.update()
def _computeDownsampleFactors(self) -> tuple[int, int]:
# reduce dimensions of image based on screen resolution
o = self.mapToDevice(QtCore.QPointF(0, 0))
x = self.mapToDevice(QtCore.QPointF(1, 0))
y = self.mapToDevice(QtCore.QPointF(0, 1))
# scene may not be available yet
if o is None:
return 1, 1
w = Point(x - o).length()
h = Point(y - o).length()
if w == 0 or h == 0:
return 1, 1
return max(1, int(1.0 / w)), max(1, int(1.0 / h))
def mouseDragEvent(self, ev):
if ev.button() != QtCore.Qt.MouseButton.LeftButton:
ev.ignore()
return
elif self.drawKernel is not None:
ev.accept()
self.drawAt(ev.pos(), ev)
def mouseClickEvent(self, ev):
if (
ev.button() == QtCore.Qt.MouseButton.RightButton and
self.raiseContextMenu(ev)
):
ev.accept()
if self.drawKernel is not None and ev.button() == QtCore.Qt.MouseButton.LeftButton:
self.drawAt(ev.pos(), ev)
def raiseContextMenu(self, ev):
menu = self.getMenu()
if menu is None:
return False
if self.scene() is None:
warnings.warn(
(
"Attempting to raise a context menu with the GraphicsScene has "
"not been set. Returning None"
),
RuntimeWarning,
stacklevel=2
)
return None
menu = self.scene().addParentContextMenus(self, menu, ev)
pos = ev.screenPos()
menu.popup(QtCore.QPoint(int(pos.x()), int(pos.y())))
return True
def getMenu(self):
if self.menu is None:
if not self.removable:
return None
self.menu = QtWidgets.QMenu()
self.menu.setTitle(translate("ImageItem", "Image"))
remAct = QtGui.QAction(translate("ImageItem", "Remove image"), self.menu)
remAct.triggered.connect(self.removeClicked)
self.menu.addAction(remAct)
self.menu.remAct = remAct
return self.menu
def hoverEvent(self, ev):
if not ev.isExit():
if self.drawKernel is not None and ev.acceptDrags(
QtCore.Qt.MouseButton.LeftButton
):
# we don't use the click, but we also don't want anyone else to use it
ev.acceptClicks(QtCore.Qt.MouseButton.LeftButton)
ev.acceptClicks(QtCore.Qt.MouseButton.RightButton)
elif self.removable:
# accept context menu clicks
ev.acceptClicks(QtCore.Qt.MouseButton.RightButton)
def tabletEvent(self, ev):
pass
def drawAt(self, pos, ev=None):
if self.axisOrder == "col-major":
pos = [int(pos.x()), int(pos.y())]
else:
pos = [int(pos.y()), int(pos.x())]
dk = self.drawKernel
kc = self.drawKernelCenter
sx = [0,dk.shape[0]]
sy = [0,dk.shape[1]]
tx = [pos[0] - kc[0], pos[0] - kc[0]+ dk.shape[0]]
ty = [pos[1] - kc[1], pos[1] - kc[1]+ dk.shape[1]]
for i in [0,1]:
dx1 = -min(0, tx[i])
dx2 = min(0, self.image.shape[0]-tx[i])
tx[i] += dx1+dx2
sx[i] += dx1+dx2
dy1 = -min(0, ty[i])
dy2 = min(0, self.image.shape[1]-ty[i])
ty[i] += dy1+dy2
sy[i] += dy1+dy2
ts = (slice(tx[0],tx[1]), slice(ty[0],ty[1]))
ss = (slice(sx[0],sx[1]), slice(sy[0],sy[1]))
mask = self.drawMask
src = dk
if isinstance(self.drawMode, Callable):
self.drawMode(dk, self.image, mask, ss, ts, ev)
else:
src = src[ss]
if self.drawMode == 'set':
if mask is not None:
mask = mask[ss]
self.image[ts] = self.image[ts] * (1-mask) + src * mask
else:
self.image[ts] = src
elif self.drawMode == 'add':
self.image[ts] += src
else:
raise ValueError(f"Unknown draw mode '{self.drawMode}'")
self.updateImage()
def setDrawKernel(self, kernel=None, mask=None, center=(0,0), mode='set'):
self.drawKernel = kernel
self.drawKernelCenter = center
self.drawMode = mode
self.drawMask = mask
def removeClicked(self):
## Send remove event only after we have exited the menu event handler
self.removeTimer = QtCore.QTimer()
self.removeTimer.timeout.connect(self.emitRemoveRequested)
self.removeTimer.start(0)
def emitRemoveRequested(self):
self.removeTimer.timeout.disconnect(self.emitRemoveRequested)
self.sigRemoveRequested.emit(self)
