Question

跟进this Question以及tcaswell提供的解决方案我尝试采用imshow()的代码来生成一个非冻结窗口，其中包含用于图像处理的滑块，例如高斯模糊过滤器。（我在彼此的顶部绘制了两个图像，因为我想在稍后阶段显示部分透明的蒙版。）

我希望你们中的一些人可能觉得这很有用，虽然我仍然可以使用一些帮助。

编辑：您可以在下面的第三节中找到当前状态。我正在为希望深入了解详细信息的其他用户保留旧版本。

我派生了两个不同的工作代码，每个代码都有一些（次要）问题，我真的很感激一些建议。

第一个代码：

只要拖动QSlider线程正在运行。但是，您不能简单地单击滑块。有什么建议吗？
图像轴未正确绘制，即它们再次消失。为什么？
情节更新不是我所说的快速，尽管它比每次调用imshow()更快。我怎样才能加快速度呢？
在更新绘图的极短时间内，窗口仍然处于冻结状态。（循环运行时窗口拖动是口吃。）可以改进吗？

为了不进入QThread: Destroyed while thread is still running我在closeEvent()中放了一个time.sleep（1）。我知道这真的很糟糕，但如果没有新的旗帜我怎么能避免呢？

import time, sys
from PyQt4 import QtCore
from PyQt4 import QtGui
from scipy import misc
from scipy import ndimage
from matplotlib.figure import Figure
import numpy as np
from matplotlib.backends.backend_qt4agg import FigureCanvasQTAgg as FigureCanvas

class ApplicationWindow(QtGui.QMainWindow):
    get_data = QtCore.pyqtSignal()
    close_request = QtCore.pyqtSignal()

    def __init__(self, parent = None):

        QtGui.QMainWindow.__init__(self, parent)

        self.thread = QtCore.QThread(parent=self)
        self.worker = Worker(parent=None)
        self.worker.moveToThread(self.thread)
        self.create_main_frame()

        self.close_request.connect(self.thread.quit)
        self.startButton.clicked.connect(self.start_calculation) 
        self.stopButton.clicked.connect(self.stop_calculation)
        self.worker.started.connect(self.thread.start)
        self.worker.new_pixel_array.connect(self.update_figure)
        self.slider.sliderPressed.connect(self.start_calculation)
        self.slider.valueChanged.connect(self.slider_value_changed)
        self.slider.sliderReleased.connect(self.stop_calculation)
        self.get_data.connect(self.worker.get_data)
        self.thread.start()

    def create_main_frame(self):
        self.main_frame = QtGui.QWidget()

        self.dpi = 100
        self.width = 5
        self.height = 5
        self.fig = Figure(figsize=(self.width, self.height), dpi=self.dpi)
        self.axes = self.fig.add_subplot(111)               
        self.axes.axis((0,512,0,512))

        self.canvas = FigureCanvas(self.fig)
        self.canvas.setParent(self.main_frame)
        self.canvas.updateGeometry()    
        self.canvas.draw()
        self.background = None
        self.background = self.canvas.copy_from_bbox(self.axes.bbox)
        self.im1 = self.axes.imshow(misc.ascent(), cmap='bone', interpolation='lanczos', extent=[0,512,0,512], aspect=(1), animated=True)        
        self.im2 = self.axes.imshow(misc.lena(), cmap='afmhot', interpolation='lanczos', extent=[0,265,0,256], aspect=(1), animated=True)  

        self.startButton = QtGui.QPushButton(self.tr("Keep Calculating"))
        self.stopButton = QtGui.QPushButton(self.tr("Stop Calculation"))
        self.slider = QtGui.QSlider(QtCore.Qt.Horizontal)
        self.slider.setRange(0, 100)
        self.slider.setValue(50)
        self.slider.setTracking(True)
        self.slider.setTickPosition(QtGui.QSlider.TicksBothSides)
        layout = QtGui.QGridLayout()
        layout.addWidget(self.canvas, 0, 0)
        layout.addWidget(self.slider, 1, 0) 
        layout.addWidget(self.startButton, 2, 0)       
        layout.addWidget(self.stopButton, 3, 0)
        self.main_frame.setLayout(layout)
        self.setCentralWidget(self.main_frame)
        self.setWindowTitle(self.tr("Gaussian Filter - Slider not clickable"))

    def slider_value_changed(self):
        #self.worker.blockSignals(False)
        self.worker.slider = self.slider.value()    

    def start_calculation(self):
        self.worker.exiting = False
        self.worker.slider = self.slider.value()
        self.startButton.setEnabled(False)
        self.stopButton.setEnabled(True)
        self.get_data.emit()

    def stop_calculation(self):
        self.worker.exiting = True
        self.startButton.setEnabled(True)
        self.stopButton.setEnabled(False)
        self.cleanup_UI()  

    def update_figure(self, im1_data,im2_data):
        self.canvas.restore_region(self.background)
        self.im1.set_array(im1_data)
        self.im2.set_array(im2_data)
        self.axes.draw_artist(self.im1) 
        self.axes.draw_artist(self.im2) 
        self.canvas.blit(self.axes.bbox)  

    def cleanup_UI(self):
        self.background = None
        self.canvas.draw()

    def closeEvent(self, event):
        self.stop_calculation()
        self.close_request.emit()
        time.sleep(1)  
        ## ugly workaround to prevent window from closing before thread is closed. (calculation takes time) How can this be avoided without additional flag?
        event.accept()        

class Worker(QtCore.QObject):

    new_pixel_array = QtCore.pyqtSignal(np.ndarray,np.ndarray)
    started = QtCore.pyqtSignal()

    def __init__(self, parent = None):
        QtCore.QObject.__init__(self, parent)
        self.exiting = True
        self.slider = 0

    @QtCore.pyqtSlot()
    def get_data(self):
        while self.exiting == False:
            self.started.emit()
            im1_data = self.gauss(misc.ascent(),self.slider)
            im2_data = self.gauss(misc.lena(),self.slider)
            self.new_pixel_array.emit(im1_data, im2_data)
            print 'Slider Value: ', self.slider  

    def gauss(self,im,radius):
        gaussed = ndimage.gaussian_filter(im, radius)
        return gaussed

def main():
    app = QtGui.QApplication(sys.argv)
    form = ApplicationWindow()
    form.show()
    app.exec_()

if __name__ == "__main__":
    main()

第二个代码：

您现在也可以点击滑块。
背景（轴）重建仍然无效。当然，在self.canvas.draw()中调用cleanup_UI()会以某种方式修复此问题。

单击滑块时，计算执行一次，但如果拖动并释放滑块，则计算将以相同的值执行两次。为什么？我试图用blockSignals捕捉到这个但有时（当滑块被快速拖动并释放时）图中的第二个图像没有正确更新。你通过两种不同的模糊来识别它。

import sys
from PyQt4 import QtCore
from PyQt4 import QtGui
from scipy import misc
from scipy import ndimage
from matplotlib.figure import Figure
import numpy as np
from matplotlib.backends.backend_qt4agg import FigureCanvasQTAgg as FigureCanvas

class ApplicationWindow(QtGui.QMainWindow):
    get_data = QtCore.pyqtSignal()

    def __init__(self, parent = None):

        QtGui.QMainWindow.__init__(self, parent)

        self.thread = QtCore.QThread(parent=self)
        self.worker = Worker(parent=None)
        self.worker.moveToThread(self.thread)
        self.create_main_frame()

        self.startButton.clicked.connect(self.start_calculation) 
        self.worker.new_pixel_array.connect(self.update_figure)
        self.worker.done.connect(self.stop_calculation)
        self.slider.sliderPressed.connect(self.start_calculation)
        self.slider.valueChanged.connect(self.slider_value_changed) 
        self.slider.actionTriggered.connect(self.start_calculation)
        self.get_data.connect(self.worker.get_data)
        self.thread.start()

    def create_main_frame(self):
        self.main_frame = QtGui.QWidget()

        self.dpi = 100
        self.width = 5
        self.height = 5
        self.fig = Figure(figsize=(self.width, self.height), dpi=self.dpi)
        self.axes = self.fig.add_subplot(111)               
        self.axes.axis((0,512,0,512))

        self.canvas = FigureCanvas(self.fig)
        self.canvas.setParent(self.main_frame)
        self.canvas.updateGeometry()    
        self.canvas.draw()
        self.background = None
        self.background = self.canvas.copy_from_bbox(self.axes.bbox)
        self.im1 = self.axes.imshow(misc.ascent(), cmap='bone', interpolation='lanczos', extent=[0,512,0,512], aspect=(1), animated=True)        
        self.im2 = self.axes.imshow(misc.lena(), cmap='afmhot', interpolation='lanczos', extent=[0,265,0,256], aspect=(1), animated=True)  

        self.startButton = QtGui.QPushButton(self.tr("Do a Calculation"))
        self.slider = QtGui.QSlider(QtCore.Qt.Horizontal)
        self.slider.setRange(0, 100)
        self.slider.setValue(50)
        self.slider.setTracking(True)
        self.slider.setTickPosition(QtGui.QSlider.TicksBothSides)
        layout = QtGui.QGridLayout()
        layout.addWidget(self.canvas, 0, 0)
        layout.addWidget(self.slider, 1, 0) 
        layout.addWidget(self.startButton, 2, 0)       

        self.main_frame.setLayout(layout)
        self.setCentralWidget(self.main_frame)
        self.setWindowTitle(self.tr("Gaussian Filter"))

    def slider_value_changed(self):
        #self.worker.blockSignals(False)
        self.worker.slider = self.slider.value()

    def start_calculation(self):
        self.slider_value_changed()
        self.worker.exiting = False
        self.startButton.setEnabled(False)
        self.get_data.emit()

    def stop_calculation(self):
        self.worker.exiting = True
        self.startButton.setEnabled(True)
        self.cleanup_UI()  

    def update_figure(self, im1_data,im2_data):  
        self.im1.set_array(im1_data)
        self.im2.set_array(im2_data)
        self.axes.draw_artist(self.im1) 
        self.axes.draw_artist(self.im2) 
        self.canvas.blit(self.axes.bbox)       

    def cleanup_UI(self):
        self.canvas.restore_region(self.background)
        #self.canvas.draw() 
        #self.worker.blockSignals(True)

class Worker(QtCore.QObject):

    new_pixel_array = QtCore.pyqtSignal(np.ndarray,np.ndarray)
    done = QtCore.pyqtSignal()

    def __init__(self, parent = None):
        QtCore.QObject.__init__(self, parent)
        self.exiting = True
        self.slider = 0

    @QtCore.pyqtSlot()
    def get_data(self):
        if self.exiting == False:
            im1_data = self.gauss(misc.ascent(),self.slider)            
            im2_data = self.gauss(misc.lena(),self.slider)
            self.new_pixel_array.emit(im1_data,im2_data)
            print 'Calculation performed, Slider Value: ', self.slider  
            self.done.emit()
        else: None

    def gauss(self,im,radius):
        gaussed = ndimage.gaussian_filter(im, radius)
        return gaussed

def main():
    app = QtGui.QApplication(sys.argv)
    form = ApplicationWindow()
    form.show()
    app.exec_()

if __name__ == "__main__":
    main()

编辑：第三段代码（已解决的主要问题和更新率有限）

滑块现在只在前一个线程的计算完成时才启动新线程。这是由disconnect实现的。
绘图仍然很慢，（模糊功能也是如此）。
restore_region似乎仍然没有效果。
我现在已将两个图像的计算放入线程中，并通过Queue()返回结果。如果你看到一些改进的可能性，请告诉我。

我曾尝试切换到multiprocessing模块并将计算放在Pool()内，但它会引发Can't pickle...错误。由于我对多处理完全陌生，我非常希望了解更多信息。

import sys
from PyQt4 import QtCore
from PyQt4 import QtGui
from scipy import misc
from scipy import ndimage
from matplotlib.figure import Figure
import numpy as np
from matplotlib.backends.backend_qt4agg import FigureCanvasQTAgg as FigureCanvas
from threading import Thread
from Queue import Queue

class ApplicationWindow(QtGui.QMainWindow):
    get_data = QtCore.pyqtSignal()

    def __init__(self, parent = None):

        QtGui.QMainWindow.__init__(self, parent)

        self.thread = QtCore.QThread(parent=self)
        self.worker = Worker(parent=None)
        self.worker.moveToThread(self.thread)
        self.create_main_frame()

        self.startButton.clicked.connect(self.start_calculation) 
        self.stopButton.clicked.connect(self.stop_calculation)
        self.worker.started.connect(self.thread.start)
        self.worker.new_pixel_array.connect(self.update_figure)
        self.slider.actionTriggered.connect(self.start_calculation)
        self.slider.valueChanged.connect(self.slider_value_changed)
        self.worker.done.connect(self.stop_calculation)
        self.get_data.connect(self.worker.get_data)
        self.thread.start()

    def create_main_frame(self):
        self.main_frame = QtGui.QWidget()

        self.dpi = 100
        self.width = 5
        self.height = 5
        self.fig = Figure(figsize=(self.width, self.height), dpi=self.dpi)
        self.axes = self.fig.add_subplot(111)               
        self.axes.axis((0,512,0,512))

        self.canvas = FigureCanvas(self.fig)
        self.canvas.setParent(self.main_frame)
        self.canvas.updateGeometry()    
        self.background = None
        self.canvas.draw()
        self.background = self.canvas.copy_from_bbox(self.axes.bbox)
        self.im1 = self.axes.imshow(misc.ascent(), cmap='bone', interpolation='lanczos', extent=[0,512,0,512], aspect=(1), animated=True)        
        self.im2 = self.axes.imshow(misc.lena(), cmap='afmhot', interpolation='lanczos', extent=[0,265,0,256], aspect=(1), animated=True)  

        self.startButton = QtGui.QPushButton(self.tr("Start Calculation"))
        self.stopButton = QtGui.QPushButton(self.tr("Stop Calculation"))
        self.slider = QtGui.QSlider(QtCore.Qt.Horizontal)
        self.slider.setRange(0, 100)
        self.slider.setValue(50)
        self.slider.setTracking(True)
        self.slider.setTickPosition(QtGui.QSlider.TicksBothSides)
        layout = QtGui.QGridLayout()
        layout.addWidget(self.canvas, 0, 0)
        layout.addWidget(self.slider, 1, 0) 
        layout.addWidget(self.startButton, 2, 0)       
        layout.addWidget(self.stopButton, 3, 0)
        self.main_frame.setLayout(layout)
        self.setCentralWidget(self.main_frame)
        self.setWindowTitle(self.tr("Gaussian Filter"))

    def slider_value_changed(self):
        self.worker.slider = self.slider.value()    

    def start_calculation(self):
        if self.worker.exiting:
            self.slider.actionTriggered.disconnect(self.start_calculation)
            self.worker.slider = self.slider.value()
            self.startButton.setEnabled(False)
            self.stopButton.setEnabled(True)
            self.get_data.emit()
            self.worker.exiting = False


    def stop_calculation(self):
        if not self.worker.exiting:
            self.slider.actionTriggered.connect(self.start_calculation)
            self.worker.exiting = True
            self.startButton.setEnabled(True)
            self.stopButton.setEnabled(False)  
        self.cleanup_UI()  

    def update_figure(self, im1_data,im2_data):
        #self.canvas.restore_region(self.background)
        self.im1.set_array(im1_data)
        self.im2.set_array(im2_data)
        self.axes.draw_artist(self.im1) 
        self.axes.draw_artist(self.im2) 
        self.canvas.blit(self.axes.bbox)  

    def cleanup_UI(self):
        self.background = None
        self.canvas.draw()    

class Worker(QtCore.QObject):

    new_pixel_array = QtCore.pyqtSignal(np.ndarray,np.ndarray)
    started = QtCore.pyqtSignal()
    done = QtCore.pyqtSignal()

    def __init__(self, parent = None):
        QtCore.QObject.__init__(self, parent)
        self.exiting = True
        self.slider = 0

    @QtCore.pyqtSlot()
    def get_data(self):
        while self.exiting == False:
            self.started.emit()
            queue1  = Queue()
            queue2  = Queue()
            im1T = Thread(target=self.gauss, args=(misc.ascent(),queue1))
            im2T = Thread(target=self.gauss, args=(misc.lena(),queue2))
            slider_val = self.slider
            im1T.start()
            im2T.start()
            im1T.join()            
            im2T.join()            
            im1_data = queue1.get() 
            im2_data = queue2.get() 
            self.new_pixel_array.emit(im1_data, im2_data)
            if slider_val == self.slider:
                self.done.emit()
                print 'Slider Value: ', self.slider  
                break

    def gauss(self,im,output_queue):
        gaussed = ndimage.gaussian_filter(im,self.slider)
        output_queue.put(gaussed)   

def main():
    app = QtGui.QApplication(sys.argv)
    form = ApplicationWindow()
    form.show()
    app.exec_()

if __name__ == "__main__":
    main()

在QThread（pyQt4）中加速imshow（）（Matplotlib）和fig.canvas.restore_region（）

0 个答案: