Skip to main content
`Ctrl`+`K`

# Source code for silx.gui.dialog.ImageFileDialog

    # /*##########################################################################
    #
    # Copyright (c) 2016-2021 European Synchrotron Radiation Facility
    #
    # Permission is hereby granted, free of charge, to any person obtaining a copy
    # of this software and associated documentation files (the "Software"), to deal
    # in the Software without restriction, including without limitation the rights
    # to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
    # copies of the Software, and to permit persons to whom the Software is
    # furnished to do so, subject to the following conditions:
    #
    # The above copyright notice and this permission notice shall be included in
    # all copies or substantial portions of the Software.
    #
    # THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
    # IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
    # FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
    # AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
    # LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
    # OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
    # THE SOFTWARE.
    #
    # ###########################################################################*/
    """
    This module contains an :class:`ImageFileDialog`.
    """

    __authors__ = ["V. Valls"]
    __license__ = "MIT"
    __date__ = "05/03/2019"

    import logging
    from silx.gui.plot import actions
    from silx.gui import qt
    from silx.gui.plot.PlotWidget import PlotWidget
    from .AbstractDataFileDialog import AbstractDataFileDialog
    import silx.io

    _logger = logging.getLogger(__name__)

    class _ImageSelection(qt.QWidget):
        """Provide a widget allowing to select an image from an hypercube by
        selecting a slice."""

        selectionChanged = qt.Signal()
        """Emitted when the selection change."""

        def __init__(self, parent=None):
            qt.QWidget.__init__(self, parent)
            self.__shape = None
            self.__axis = []
            layout = qt.QVBoxLayout()
            self.setLayout(layout)

        def hasVisibleSelectors(self):
            return self.__visibleSliders > 0

        def isUsed(self):
            if self.__shape is None:
                return False
            return len(self.__shape) > 2

        def getSelectedData(self, data):
            slicing = self.slicing()
            image = data[slicing]
            return image

        def setData(self, data):
            if data is None:
                self.__visibleSliders = 0
                return

            shape = data.shape
            if self.__shape is not None:
                # clean up
                for widget in self.__axis:
                    self.layout().removeWidget(widget)
                    widget.deleteLater()
                self.__axis = []

            self.__shape = shape
            self.__visibleSliders = 0

            if shape is not None:
                # create expected axes
                for index in range(len(shape) - 2):
                    axis = qt.QSlider(self)
                    axis.setMinimum(0)
                    axis.setMaximum(shape[index] - 1)
                    axis.setOrientation(qt.Qt.Horizontal)
                    if shape[index] == 1:
                        axis.setVisible(False)
                    else:
                        self.__visibleSliders += 1

                    axis.valueChanged.connect(self.__axisValueChanged)
                    self.layout().addWidget(axis)
                    self.__axis.append(axis)

            self.selectionChanged.emit()

        def __axisValueChanged(self):
            self.selectionChanged.emit()

        def slicing(self):
            slicing = []
            for axes in self.__axis:
                slicing.append(axes.value())
            return tuple(slicing)

        def setSlicing(self, slicing):
            for i, value in enumerate(slicing):
                if i > len(self.__axis):
                    break
                self.__axis[i].setValue(value)

        def selectSlicing(self, slicing):
            """Select a slicing.

            The provided value could be unconsistent and therefore is not supposed
            to be retrivable with a getter.

            :param Union[None,Tuple[int]] slicing:
            """
            if slicing is None:
                # Create a default slicing
                needed = self.__visibleSliders
                slicing = (0,) * needed
            if len(slicing) < self.__visibleSliders:
                slicing = slicing + (0,) * (self.__visibleSliders - len(slicing))
            self.setSlicing(slicing)

    class _ImagePreview(qt.QWidget):
        """Provide a preview of the selected image"""

        def __init__(self, parent=None):
            super(_ImagePreview, self).__init__(parent)

            self.__data = None
            self.__plot = PlotWidget(self)
            self.__plot.setAxesDisplayed(False)
            self.__plot.setKeepDataAspectRatio(True)
            layout = qt.QVBoxLayout()
            layout.setContentsMargins(0, 0, 0, 0)
            layout.addWidget(self.__plot)
            self.setLayout(layout)

        def resizeEvent(self, event):
            self.__updateConstraints()
            return qt.QWidget.resizeEvent(self, event)

        def sizeHint(self):
            return qt.QSize(200, 200)

        def plot(self):
            return self.__plot

        def setData(self, data, fromDataSelector=False):
            if data is None:
                self.clear()
                return

            resetzoom = not fromDataSelector
            previousImage = self.data()
            if previousImage is not None and data.shape != previousImage.shape:
                resetzoom = True

            self.__plot.addImage(legend="data", data=data, resetzoom=resetzoom)
            self.__data = data
            self.__updateConstraints()

        def __updateConstraints(self):
            """
            Update the constraints depending on the size of the widget
            """
            image = self.data()
            if image is None:
                return
            size = self.size()
            if size.width() == 0 or size.height() == 0:
                return

            heightData, widthData = image.shape

            widthContraint = heightData * size.width() / size.height()
            if widthContraint > widthData:
                heightContraint = heightData
            else:
                heightContraint = heightData * size.height() / size.width()
                widthContraint = widthData

            midWidth, midHeight = widthData * 0.5, heightData * 0.5
            heightContraint, widthContraint = heightContraint * 0.5, widthContraint * 0.5

            axis = self.__plot.getXAxis()
            axis.setLimitsConstraints(midWidth - widthContraint, midWidth + widthContraint)
            axis = self.__plot.getYAxis()
            axis.setLimitsConstraints(
                midHeight - heightContraint, midHeight + heightContraint
            )

        def __imageItem(self):
            image = self.__plot.getImage("data")
            return image

        def data(self):
            if self.__data is not None:
                if hasattr(self.__data, "name"):
                    # in case of HDF5
                    if self.__data.name is None:
                        # The dataset was closed
                        self.__data = None
            return self.__data

        def colormap(self):
            image = self.__imageItem()
            if image is not None:
                return image.getColormap()
            return self.__plot.getDefaultColormap()

        def setColormap(self, colormap):
            self.__plot.setDefaultColormap(colormap)

        def clear(self):
            self.__data = None
            image = self.__imageItem()
            if image is not None:
                self.__plot.removeImage(legend="data")

    class ImageFileDialog(AbstractDataFileDialog):
        """The `ImageFileDialog` class provides a dialog that allow users to select
        an image from a file.

        The `ImageFileDialog` class enables a user to traverse the file system in
        order to select one file. Then to traverse the file to select a frame or
        a slice of a dataset.

        .. image:: img/imagefiledialog_h5.png

        It supports fast access to image files using `FabIO`. Which is not the case
        of the default silx API. Image files still also can be available using the
        NeXus layout, by editing the file type combo box.

        .. image:: img/imagefiledialog_edf.png

        The selected data is an numpy array with 2 dimension.

        Using an `ImageFileDialog` can be done like that.

        .. code-block:: python

            dialog = ImageFileDialog()
            result = dialog.exec()
            if result:
                print("Selection:")
                print(dialog.selectedFile())
                print(dialog.selectedUrl())
                print(dialog.selectedImage())
            else:
                print("Nothing selected")
        """

        def selectedImage(self):
            """Returns the selected image data as numpy

            :rtype: numpy.ndarray
            """
            url = self.selectedUrl()
            return silx.io.get_data(url)

        def _createPreviewWidget(self, parent):
            previewWidget = _ImagePreview(parent)
            previewWidget.setSizePolicy(qt.QSizePolicy.Expanding, qt.QSizePolicy.Expanding)
            return previewWidget

        def _createSelectorWidget(self, parent):
            return _ImageSelection(parent)

        def _createPreviewToolbar(self, parent, dataPreviewWidget, dataSelectorWidget):
            plot = dataPreviewWidget.plot()
            toolbar = qt.QToolBar(parent)
            toolbar.setIconSize(qt.QSize(16, 16))
            toolbar.setStyleSheet("QToolBar { border: 0px }")
            toolbar.addAction(actions.mode.ZoomModeAction(plot, parent))
            toolbar.addAction(actions.mode.PanModeAction(plot, parent))
            toolbar.addSeparator()
            toolbar.addAction(actions.control.ResetZoomAction(plot, parent))
            toolbar.addSeparator()
            toolbar.addAction(actions.control.ColormapAction(plot, parent))
            return toolbar

        def _isDataSupportable(self, data):
            """Check if the selected data can be supported at one point.

            If true, the data selector will be checked and it will update the data
            preview. Else the selecting is disabled.

            :rtype: bool
            """
            if not hasattr(data, "dtype"):
                # It is not an HDF5 dataset nor a fabio image wrapper
                return False

            if data is None or data.shape is None:
                return False

            if data.dtype.kind not in set(["f", "u", "i", "b"]):
                return False

            dim = len(data.shape)
            return dim >= 2

        def _isFabioFilesSupported(self):
            return True

        def _isDataSupported(self, data):
            """Check if the data can be returned by the dialog.

            If true, this data can be returned by the dialog and the open button
            while be enabled. If false the button will be disabled.

            :rtype: bool
            """
            dim = len(data.shape)
            return dim == 2

        def _displayedDataInfo(self, dataBeforeSelection, dataAfterSelection):
            """Returns the text displayed under the data preview.

            This zone is used to display error in case or problem of data selection
            or problems with IO.

            :param numpy.ndarray dataAfterSelection: Data as it is after the
                selection widget (basically the data from the preview widget)
            :param numpy.ndarray dataAfterSelection: Data as it is before the
                selection widget (basically the data from the browsing widget)
            :rtype: bool
            """
            destination = self.__formatShape(dataAfterSelection.shape)
            source = self.__formatShape(dataBeforeSelection.shape)
            return "%s \u2192 %s" % (source, destination)

        def __formatShape(self, shape):
            result = []
            for s in shape:
                if isinstance(s, slice):
                    v = "\u2026"
                else:
                    v = str(s)
                result.append(v)
            return " \u00D7 ".join(result)