segfault on application exit

[Fabian Isensee]

Hey there,

I implemented a very basic image viewer that is supposed to show a batch of image stacks that are synced together, meaning that the same slice number should be displayed for all stacks. The viewer runs very well, but I get a Segmentation fault (core dumped) after closing the application. I have been trying to fix this for a while now but don't find the mistake. Your help would be very much appreciated!

Here is my code. It runs out of the box (displays random noise).

Cheers,

Fabian

from pyqtgraph.Qt import QtGui, QtCore
import pyqtgraph as pg
import sys
import numpy as np

class ImageViewer2DWidget(QtGui.QWidget):
    def __init__(self, width=300, height=300):
        QtGui.QWidget.__init__(self)
        self.image = None
        self.init(width, height)

    def init(self, width, height):
        self.rect = QtCore.QRect(0, 0, width, height)
        self.imageItem = pg.ImageItem()
        self.imageItem.setImage(None)

        self.graphicsScene = pg.GraphicsScene()
        self.graphicsScene.addItem(self.imageItem)

        self.graphicsView = pg.GraphicsView()
        self.graphicsView.setRenderHint(QtGui.QPainter.Antialiasing)
        self.graphicsView.setScene(self.graphicsScene)

        layout = QtGui.QHBoxLayout()
        layout.addWidget(self.graphicsView)
        self.setLayout(layout)
        self.setMaximumSize(width, height)
        self.setMinimumSize(width-10, height-10)

    def setImage(self, image):
        assert len(image.shape) == 2 or len(image.shape) == 3
        if len(image.shape) == 4:
            assert image.shape[-1] == 4
        self.image = image
        self.imageItem.setImage(self.image)
        self.imageItem.setRect(self.rect)

    def setLevels(self, levels, update=True):
        self.imageItem.setLevels(levels, update)

class ImageSlicingWidget(ImageViewer2DWidget):
    def __init__(self, width=300, height=300):
        self.slice = 0
        ImageViewer2DWidget.__init__(self, width, height)

    def setImage(self, image):
        assert len(image.shape) == 3 or len(image.shape) == 4
        if len(image.shape) == 4:
            assert image.shape[-1] == 4
        self.image = image
        self._updateImageSlice()

    def _updateImageSlice(self):
        self.imageItem.setImage(self.image[self.slice])
        self.imageItem.setRect(self.rect)

    def setSlice(self, slice):
        slice = np.max((0, slice))
        slice = np.min((slice, self.image.shape[0] - 1))
        self.slice = slice
        self._updateImageSlice()

    def getSlice(self):
        return self.slice

class BatchViewer(QtGui.QWidget):
    def __init__(self, width=300, height=300):
        QtGui.QWidget.__init__(self)
        self.batch = None
        self.width = width
        self.height = height
        self.slicingWidgets = {}
        self._init_gui()

    def setBatch(self, batch):
        assert len(batch.shape) == 4
        for v in self.slicingWidgets.values():
            self._my_layout.removeWidget(v)
        self.slicingWidgets = {}

        self.batch = batch
        for i in range(self.batch.shape[0]):
            w = ImageSlicingWidget(self.width, self.height)
            w.setImage(self.batch[i])
            w.setLevels([self.batch[i].min(), self.batch[i].max()])
            w.setSlice(0)
            self._my_layout.addWidget(w)
            self.slicingWidgets[i] = w

    def _init_gui(self):
        self._my_layout = QtGui.QHBoxLayout()
        self.slicingWidgets = {}
        self.setLayout(self._my_layout)
        self.setWindowTitle("Batch Viewer")

    def wheelEvent(self, QWheelEvent):
        for v in self.slicingWidgets.values():
            v.setSlice(v.getSlice() + QWheelEvent.delta()/120)



if __name__ == '__main__':
    app = QtGui.QApplication(sys.argv)
    sv = BatchViewer()
    batch = np.random.random((5, 300, 300, 300))
    sv.setBatch(batch)
    sv.show()
    if (sys.flags.interactive != 1) or not hasattr(QtCore, 'PYQT_VERSION'):
        app.exec_()
    # import IPython
    # IPython.embed()

[vas...@gmail.com]

Have no problems with your code on Windows. Maybe you could try to add few lines to the end of your code to look like:

if (sys.flags.interactive != 1) or not hasattr(QtCore, 'PYQT_VERSION'):
  app.exec_()

  app.deleteLater()
  sys.exit()

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[Fabian Isensee]

Hi,

thank you very much! That fixed the problem!

Cheers,

Fabian

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