Source code for pyqtgraph.graphicsItems.ImageItem

# -*- coding: utf-8 -*-
import numpy

from .GraphicsObject import GraphicsObject
from .. import debug as debug
from .. import functions as fn
from .. import getConfigOption
from ..Point import Point
from ..Qt import QtGui, QtCore
from ..util.cupy_helper import getCupy

import warnings
from import Callable

translate = QtCore.QCoreApplication.translate

__all__ = ['ImageItem']

[docs]class ImageItem(GraphicsObject): """ **Bases:** :class:`GraphicsObject <pyqtgraph.GraphicsObject>` """ # Overall description of ImageItem (including examples) moved to documentation text sigImageChanged = QtCore.Signal() sigRemoveRequested = QtCore.Signal(object) # self; emitted when 'remove' is selected from context menu
[docs] def __init__(self, image=None, **kargs): """ See :func:`~pyqtgraph.ImageItem.setOpts` for further keyword arguments and and :func:`~pyqtgraph.ImageItem.setImage` for information on supported formats. Parameters ---------- image: array Image data """ GraphicsObject.__init__(self) = 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._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.axisOrder = getConfigOption('imageAxisOrder') self._dataTransform = self._inverseDataTransform = None self._update_data_transforms( self.axisOrder ) # install initial transforms # In some cases, we use a modified lookup table to handle both rescaling # and LUT more efficiently self._effectiveLut = None 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): """ Change the composition mode of the item. This is useful when overlaying multiple items. Parameters ---------- mode : ``QtGui.QPainter.CompositionMode`` Composition of the item, often used when overlaying items. Common options include: ``QPainter.CompositionMode.CompositionMode_SourceOver`` (Default) Image replaces the background if it is opaque. Otherwise, it uses the alpha channel to blend the image with the background. ``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 ``QPainter::CompositionMode`` in the Qt Documentation for more options and details """ self.paintMode = mode self.update()
[docs] def setBorder(self, b): """ Defines the border drawn around the image. Accepts all arguments supported by :func:`~pyqtgraph.functions.mkPen`. """ self.border = fn.mkPen(b) self.update()
def width(self): if self.image is None: return None axis = 0 if self.axisOrder == 'col-major' else 1 return self.image.shape[axis] def height(self): if self.image is None: return None axis = 1 if self.axisOrder == 'col-major' else 0 return self.image.shape[axis] def channels(self): if self.image is None: return None return self.image.shape[2] if self.image.ndim == 3 else 1 def boundingRect(self): if self.image is None: return QtCore.QRectF(0., 0., 0., 0.) return QtCore.QRectF(0., 0., float(self.width()), float(self.height()))
[docs] def setLevels(self, levels, update=True): """ Sets image scaling levels. See :func:`makeARGB <pyqtgraph.makeARGB>` for more details on how levels are applied. Parameters ---------- levels: list_like - [`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. update: bool, optional Controls if image immediately updates to reflect the new levels. """ 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 self._effectiveLut = None if update: self.updateImage()
[docs] def getLevels(self): """ Returns the list representing the current level settings. See :func:`~setLevels`. When ``autoLevels`` is active, the format is [`blackLevel`, `whiteLevel`]. """ return self.levels
[docs] def setLookupTable(self, lut, update=True): """ Sets lookup table `lut` to use for false color display of a monochrome image. See :func:`makeARGB <pyqtgraph.makeARGB>` for more information on how this is used. Optionally, `lut` can be a callable that accepts the current image as an argument and returns the lookup table to use. Ordinarily, this table is supplied by a :class:`~pyqtgraph.HistogramLUTItem`, :class:`~pyqtgraph.GradientEditorItem` or :class:`~pyqtgraph.ColorBarItem`. Setting `update` to False avoids an immediate image update. """ if lut is not self.lut: if self._xp is not None: lut = self._ensure_proper_substrate(lut, self._xp) self.lut = lut self._effectiveLut = None if update: self.updateImage()
@staticmethod def _ensure_proper_substrate(data, substrate): if data is None or isinstance(data, Callable) or isinstance(data, substrate.ndarray): return data cupy = getCupy() if substrate == cupy and not isinstance(data, cupy.ndarray): data = cupy.asarray(data) elif substrate == numpy: if cupy is not None and isinstance(data, cupy.ndarray): data = data.get() else: data = numpy.asarray(data) return data
[docs] def setAutoDownsample(self, active=True): """ Controls automatic downsampling for this ImageItem. 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 setOpts(self, update=True, **kargs): """ Sets display and processing options for this ImageItem. :func:`~pyqtgraph.ImageItem.__init__` and :func:`~pyqtgraph.ImageItem.setImage` support all keyword arguments listed here. Parameters ---------- autoDownsample: bool See :func:`~pyqtgraph.ImageItem.setAutoDownsample`. axisOrder: str | `'col-major'`: The shape of the array represents (width, height) of the image. This is the default. | `'row-major'`: The shape of the array represents (height, width). border: bool Sets a pen to draw to draw an image border. See :func:`~pyqtgraph.ImageItem.setBorder`. compositionMode: See :func:`~pyqtgraph.ImageItem.setCompositionMode` lut: array Sets a color lookup table to use when displaying the image. See :func:`~pyqtgraph.ImageItem.setLookupTable`. levels: list_like, usally [`min`, `max`] Sets minimum and maximum values to use when rescaling the image data. By default, these will be set to the estimated minimum and maximum values in the image. If the image array has dtype uint8, no rescaling is necessary. See :func:`~pyqtgraph.ImageItem.setLevels`. opacity: float, 0.0-1.0 Overall opacity for an RGB image. rect: QRectF, QRect or array_like of floats (`x`,`y`,`w`,`h`) Displays the current image within the specified rectangle in plot coordinates. See :func:`~pyqtgraph.ImageItem.setRect`. update : bool, optional Controls if image immediately updates to reflect the new options. """ if 'axisOrder' in kargs: val = kargs['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 'lut' in kargs: self.setLookupTable(kargs['lut'], update=update) if 'levels' in kargs: self.setLevels(kargs['levels'], update=update) #if 'clipLevel' in kargs: #self.setClipLevel(kargs['clipLevel']) if 'opacity' in kargs: self.setOpacity(kargs['opacity']) if 'compositionMode' in kargs: self.setCompositionMode(kargs['compositionMode']) if 'border' in kargs: self.setBorder(kargs['border']) if 'removable' in kargs: self.removable = kargs['removable'] = None if 'autoDownsample' in kargs: self.setAutoDownsample(kargs['autoDownsample']) if 'rect' in kargs: self.setRect(kargs['rect']) if update: self.update()
[docs] def setRect(self, *args): """ setRect(rect) or setRect(x,y,w,h) Sets translation and scaling of this ImageItem to display the current image within the rectangle given as ``QtCore.QRect`` or ``QtCore.QRectF`` `rect`, or described by parameters `x, y, w, h`, defining starting position, width and height. This method cannot be used before an image is assigned. See the :ref:`examples <ImageItem_examples>` for how to manually set transformations. """ if len(args) == 0: self.resetTransform() # reset scaling and rotation when called without argument 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 rect = QtCore.QRectF( *args ) # QRectF(x,y,w,h), but also accepts other initializers tr = QtGui.QTransform() tr.translate(rect.left(), tr.scale(rect.width() / self.width(), rect.height() / self.height()) self.setTransform(tr)
[docs] def clear(self): """ Clears the assigned image. """ self.image = None self.prepareGeometryChange() self.informViewBoundsChanged() self.update()
def _buildQImageBuffer(self, shape): self._displayBuffer = numpy.empty(shape[:2] + (4,), dtype=numpy.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=None, autoLevels=None, **kargs): """ Updates the image displayed by this ImageItem. For more information on how the image is processed before displaying, see :func:`~pyqtgraph.makeARGB>`. 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:: 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>`. All keywords supported by :func:`~pyqtgraph.ImageItem.setOpts` are also allowed here. Parameters ---------- image: array 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). rect: QRectF, QRect or list_like of floats (`x, y, w, h`), optional If given, sets translation and scaling to display the image within the specified rectangle. See :func:`~pyqtgraph.ImageItem.setRect`. autoLevels: bool, optional If True, ImageItem will automatically select levels based on the maximum and minimum values encountered in the data. For performance reasons, this search subsamples the images and may miss individual bright or or dark points in the data set. If False, the search will be omitted. The default is `False` if a ``levels`` keyword argument is given, and `True` otherwise. levelSamples: int, default 65536 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. """ 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 numpy 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() if self.image is None or image.dtype != self.image.dtype: self._effectiveLut = None self.image = image if self.image.shape[0] > 2**15-1 or self.image.shape[1] > 2**15-1: if 'autoDownsample' not in kargs: kargs['autoDownsample'] = True if shapeChanged: self.prepareGeometryChange() self.informViewBoundsChanged() profile() if autoLevels is None: if 'levels' in kargs: autoLevels = False else: autoLevels = True if autoLevels: level_samples = kargs.pop('levelSamples', 2**16) mn, mx = self.quickMinMax( targetSize=level_samples ) # 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 kargs['levels'] = [mn,mx] profile() self.setOpts(update=False, **kargs) 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='col-major'): """ Sets up the transforms needed to map between input array and display """ 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): """ Returns the transform that maps from this image's input array to its local coordinate system. This transform corrects for the transposition that occurs when image data is interpreted in row-major order. :meta private: """ # Might eventually need to account for downsampling / clipping here # transforms are updated in setOpts call. return self._dataTransform def inverseDataTransform(self): """Return the transform that maps from this image's local coordinate system to its input array. See dataTransform() for more information. :meta private: """ # transforms are updated in setOpts call. return self._inverseDataTransform def mapToData(self, obj): return def mapFromData(self, obj): return
[docs] def quickMinMax(self, targetSize=1e6): """ Estimates the min/max values of the image data by subsampling. Subsampling is performed at regular strides chosen to evaluate a number of samples equal to or less than `targetSize`. Returns (`min`, `max`). """ data = self.image if targetSize < 2: # keep at least two pixels targetSize = 2 while True: h, w = data.shape[:2] if h * w <= targetSize: break if h > w: data = data[::2, ::] # downsample first axis else: data = data[::, ::2] # downsample second axis return self._xp.nanmin(data), self._xp.nanmax(data)
def updateImage(self, *args, **kargs): ## used for re-rendering qimage from self.image. ## can we make any assumptions here that speed things up? ## dtype, range, size are all the same? defaults = { 'autoLevels': False, } defaults.update(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), self._xp) else: lut = self.lut else: lut = None if self.autoDownsample: xds, yds = self._computeDownsampleFactors() if xds is None: return axes = [1, 0] if self.axisOrder == 'row-major' else [0, 1] image = fn.downsample(self.image, xds, axis=axes[0]) image = fn.downsample(image, yds, axis=axes[1]) self._lastDownsample = (xds, yds) # Check if downsampling reduced the image size to zero due to inf values. if image.size == 0: return else: image = self.image # 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 augmented_alpha = False if lut is not None and lut.dtype != self._xp.uint8: # Both _try_rescale_float() and _try_combine_lut() assume that # lut is of type uint8. It is considered a usage error if that # is not the case. # However, the makeARGB() codepath 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 image.dtype.kind == 'f': image, levels, lut, augmented_alpha = self._try_rescale_float(image, levels, lut) # if we succeeded, we will have an uint8 image with levels None. # lut if not None will have <= 256 entries # if the image data is a small int, then we can combine levels + lut # into a single lut for better performance elif image.dtype in (self._xp.ubyte, self._xp.uint16): image, levels, lut, augmented_alpha = self._try_combine_lut(image, levels, lut) qimage = self._try_make_qimage(image, levels, lut, augmented_alpha) 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 _try_rescale_float(self, image, levels, lut): xp = self._xp augmented_alpha = False can_handle = False while True: if levels is None or levels.ndim != 1: # float images always need levels # can't handle multi-channel levels break # awkward, but fastest numpy native nan evaluation if xp.isnan(image.min()): # don't handle images with nans # this should be an uncommon case break can_handle = True break if not can_handle: return image, levels, lut, augmented_alpha # Decide on maximum scaled value if lut is not None: scale = lut.shape[0] num_colors = lut.shape[0] else: scale = 255. num_colors = 256 dtype = xp.min_scalar_type(num_colors-1) minVal, maxVal = levels if minVal == maxVal: maxVal = xp.nextafter(maxVal, 2*maxVal) rng = maxVal - minVal rng = 1 if rng == 0 else rng fn_numba = fn.getNumbaFunctions() if xp == numpy and image.flags.c_contiguous and dtype == xp.uint16 and fn_numba is not None: lut, augmented_alpha = self._convert_2dlut_to_1dlut(lut) image = fn_numba.rescale_and_lookup1d(image, scale/rng, minVal, lut) if image.dtype == xp.uint32: image = image[..., xp.newaxis].view(xp.uint8) return image, None, None, augmented_alpha else: image = fn.rescaleData(image, scale/rng, offset=minVal, dtype=dtype, clip=(0, num_colors-1)) levels = None if image.dtype == xp.uint16 and image.ndim == 2: image, augmented_alpha = self._apply_lut_for_uint16_mono(image, lut) lut = None # image is now of type uint8 return image, levels, lut, augmented_alpha def _try_combine_lut(self, image, levels, lut): augmented_alpha = False xp = self._xp can_handle = False while True: if levels is not None and levels.ndim != 1: # can't handle multi-channel levels break if image.dtype == xp.uint16 and levels is None and \ image.ndim == 3 and image.shape[2] == 3: # uint16 rgb can't be directly displayed, so make it # pass through effective lut processing levels = [0, 65535] if levels is None and lut is None: # nothing to combine break can_handle = True break if not can_handle: return image, levels, lut, augmented_alpha # distinguish between lut for levels and colors levels_lut = None colors_lut = lut lut = None eflsize = 2**(image.itemsize*8) if levels is None: info = xp.iinfo(image.dtype) minlev, maxlev = info.min, info.max else: minlev, maxlev = levels levdiff = maxlev - minlev levdiff = 1 if levdiff == 0 else levdiff # don't allow division by 0 if colors_lut is None: if image.dtype == xp.ubyte and image.ndim == 2: # uint8 mono image ind = xp.arange(eflsize) levels_lut = fn.rescaleData(ind, scale=255./levdiff, offset=minlev, dtype=xp.ubyte) # image data is not scaled. instead, levels_lut is used # as (grayscale) Indexed8 ColorTable to get the same effect. # due to the small size of the input to rescaleData(), we # do not bother caching the result return image, None, levels_lut, augmented_alpha else: # uint16 mono, uint8 rgb, uint16 rgb # rescale image data by computation instead of by memory lookup image = fn.rescaleData(image, scale=255./levdiff, offset=minlev, dtype=xp.ubyte) return image, None, colors_lut, augmented_alpha else: num_colors = colors_lut.shape[0] effscale = num_colors / levdiff lutdtype = xp.min_scalar_type(num_colors - 1) if image.dtype == xp.ubyte or lutdtype != xp.ubyte: # combine if either: # 1) uint8 mono image # 2) colors_lut has more entries than will fit within 8-bits if self._effectiveLut is None: ind = xp.arange(eflsize) levels_lut = fn.rescaleData(ind, scale=effscale, offset=minlev, dtype=lutdtype, clip=(0, num_colors-1)) efflut = colors_lut[levels_lut] levels_lut = None colors_lut = None self._effectiveLut = efflut efflut = self._effectiveLut # apply the effective lut early for the following types: if image.dtype == xp.uint16 and image.ndim == 2: image, augmented_alpha = self._apply_lut_for_uint16_mono(image, efflut) efflut = None return image, None, efflut, augmented_alpha else: # uint16 image with colors_lut <= 256 entries # don't combine, we will use QImage ColorTable image = fn.rescaleData(image, scale=effscale, offset=minlev, dtype=lutdtype, clip=(0, num_colors-1)) return image, None, colors_lut, augmented_alpha def _apply_lut_for_uint16_mono(self, image, lut): # Note: compared to makeARGB(), we have already clipped the data to range xp = self._xp augmented_alpha = False # if lut is 1d, then lut[image] is fastest # if lut is 2d, then lut.take(image, axis=0) is faster than lut[image] if not image.flags.c_contiguous: image = lut.take(image, axis=0) # if lut had dimensions (N, 1), then our resultant image would # have dimensions (h, w, 1) if image.ndim == 3 and image.shape[-1] == 1: image = image[..., 0] return image, augmented_alpha # if we are contiguous, we can take a faster codepath where we # ensure that the lut is 1d lut, augmented_alpha = self._convert_2dlut_to_1dlut(lut) fn_numba = fn.getNumbaFunctions() if xp == numpy and fn_numba is not None: image = fn_numba.numba_take(lut, image) else: image = lut[image] if image.dtype == xp.uint32: image = image[..., xp.newaxis].view(xp.uint8) return image, augmented_alpha def _convert_2dlut_to_1dlut(self, lut): # converts: # - uint8 (N, 1) to uint8 (N,) # - uint8 (N, 3) or (N, 4) to uint32 (N,) # this allows faster lookup as 1d lookup is faster xp = self._xp augmented_alpha = False if lut.ndim == 1: return lut, augmented_alpha if lut.shape[1] == 3: # rgb # convert rgb lut to rgba so that it is 32-bits lut = xp.column_stack([lut, xp.full(lut.shape[0], 255, dtype=xp.uint8)]) augmented_alpha = True if lut.shape[1] == 4: # rgba lut = lut.view(xp.uint32) lut = lut.ravel() return lut, augmented_alpha def _try_make_qimage(self, image, levels, lut, augmented_alpha): xp = self._xp ubyte_nolvl = image.dtype == xp.ubyte and levels is None is_passthru8 = ubyte_nolvl and lut is None is_indexed8 = ubyte_nolvl and image.ndim == 2 and \ lut is not None and lut.shape[0] <= 256 is_passthru16 = image.dtype == xp.uint16 and levels is None and lut is None can_grayscale16 = is_passthru16 and image.ndim == 2 and \ hasattr(QtGui.QImage.Format, 'Format_Grayscale16') is_rgba64 = is_passthru16 and image.ndim == 3 and image.shape[2] == 4 # bypass makeARGB for supported combinations supported = is_passthru8 or is_indexed8 or can_grayscale16 or is_rgba64 if not supported: return None if self._xp == getCupy(): image = image.get() # worthwhile supporting non-contiguous arrays image = numpy.ascontiguousarray(image) fmt = None ctbl = None if is_passthru8: # both levels and lut are None # these images are suitable for display directly if image.ndim == 2: fmt = QtGui.QImage.Format.Format_Grayscale8 elif image.shape[2] == 3: fmt = QtGui.QImage.Format.Format_RGB888 elif image.shape[2] == 4: if augmented_alpha: fmt = QtGui.QImage.Format.Format_RGBX8888 else: fmt = QtGui.QImage.Format.Format_RGBA8888 elif is_indexed8: # levels and/or lut --> lut-only fmt = QtGui.QImage.Format.Format_Indexed8 if lut.ndim == 1 or lut.shape[1] == 1: ctbl = [QtGui.qRgb(x,x,x) for x in lut.ravel().tolist()] elif lut.shape[1] == 3: ctbl = [QtGui.qRgb(*rgb) for rgb in lut.tolist()] elif lut.shape[1] == 4: ctbl = [QtGui.qRgba(*rgba) for rgba in lut.tolist()] elif can_grayscale16: # single channel uint16 # both levels and lut are None fmt = QtGui.QImage.Format.Format_Grayscale16 elif is_rgba64: # uint16 rgba # both levels and lut are None fmt = QtGui.QImage.Format.Format_RGBA64 # endian-independent if fmt is None: raise ValueError("unsupported image type") qimage = fn.ndarray_to_qimage(image, fmt) if ctbl is not None: qimage.setColorTable(ctbl) return qimage def paint(self, p, *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: p.setCompositionMode(self.paintMode) profile('set comp mode') shape = self.image.shape[:2] if self.axisOrder == 'col-major' else self.image.shape[:2][::-1] p.drawImage(QtCore.QRectF(0,0,*shape), self.qimage) profile('p.drawImage') if self.border is not None: p.setPen(self.border) p.drawRect(self.boundingRect())
[docs] def save(self, fileName, *args): """ Saves this image to file. Note that this saves the visible image (after scale/color changes), not the original data. """ if self._renderRequired: self.render(), *args)
[docs] def getHistogram(self, bins='auto', step='auto', perChannel=False, targetImageSize=200, targetHistogramSize=500, **kwds): """ Returns `x` and `y` arrays containing the histogram values for the current image. For an explanation of the return format, see numpy.histogram(). 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. The `bins` argument and any extra keyword arguments are passed to ``self.xp.histogram()``. If `bins` is `auto`, a bin number is automatically chosen based on the image characteristics: * Integer images will have approximately `targetHistogramSize` bins, with each bin having an integer width. * All other types will have `targetHistogramSize` bins. If `perChannel` is `True`, then a histogram is computed for each channel, and the output is a list of the results. """ # 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)) kwds['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, **kwds) 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, **kwds) if cp: return cp.asnumpy(hist[1][:-1]), cp.asnumpy(hist[0]) else: return hist[1][:-1], hist[0]
[docs] def setPxMode(self, b): """ Sets whether the item ignores transformations and draws directly to screen pixels. 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 ``GraphicsItem::ItemIgnoresTransformations`` in the Qt documentation) """ self.setFlag(self.GraphicsItemFlag.ItemIgnoresTransformations, b)
def setScaledMode(self): self.setPxMode(False) def getPixmap(self): if self._renderRequired: self.render() if self._unrenderable: return None return QtGui.QPixmap.fromImage(self.qimage)
[docs] def pixelSize(self): """ Returns the scene-size of a single pixel in the image """ br = self.sceneBoundingRect() if self.image is None: return 1,1 return br.width()/self.width(), br.height()/self.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): # 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 None, None w = Point(x - o).length() h = Point(y - o).length() if w == 0 or h == 0: return None, None 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: if 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 menu = self.scene().addParentContextMenus(self, menu, ev) pos = ev.screenPos() menu.popup(QtCore.QPoint(pos.x(), pos.y())) return True def getMenu(self): if is None: if not self.removable: return None = QtGui.QMenu()"ImageItem", "Image")) remAct = QtGui.QAction(translate("ImageItem", "Remove image"), remAct.triggered.connect(self.removeClicked) = remAct return def hoverEvent(self, ev): if not ev.isExit() and self.drawKernel is not None and ev.acceptDrags(QtCore.Qt.MouseButton.LeftButton): ev.acceptClicks(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.RightButton) elif not ev.isExit() and self.removable: ev.acceptClicks(QtCore.Qt.MouseButton.RightButton) ## accept context menu clicks def tabletEvent(self, ev): pass #print(ev.device()) #print(ev.pointerType()) #print(ev.pressure()) def drawAt(self, pos, ev=None): pos = [int(pos.x()), int(pos.y())] 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 Exception("Unknown draw mode '%s'" % 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)