我是Python和PyQt的初学者。我尝试基于acbetter的代码创建图像查看器，并希望添加图像裁剪功能。最终，我要使用这两个代码创建一个代码，在其中可以打开某个图像并裁剪图像的特定部分，然后在另一个窗口中显示它。您想帮助如何组合这两个代码吗？
from PyQt5.QtCore import Qt
from PyQt5.QtGui import QImage, QPixmap, QPalette, QPainter
from PyQt5.QtPrintSupport import QPrintDialog, QPrinter
from PyQt5.QtWidgets import QLabel, QSizePolicy, QScrollArea, QMessageBox, QMainWindow, QMenu, QAction, \
qApp, QFileDialog
class QImageViewer(QMainWindow):
def __init__(self):
super().__init__()
self.printer = QPrinter()
self.scaleFactor = 0.0
self.imageLabel = QLabel()
self.imageLabel.setBackgroundRole(QPalette.Base)
self.imageLabel.setSizePolicy(QSizePolicy.Ignored, QSizePolicy.Ignored)
self.imageLabel.setScaledContents(True)
self.scrollArea = QScrollArea()
self.scrollArea.setBackgroundRole(QPalette.Dark)
self.scrollArea.setWidget(self.imageLabel)
self.scrollArea.setVisible(False)
self.setCentralWidget(self.scrollArea)
self.createActions()
self.createMenus()
self.setWindowTitle("Image Viewer")
self.resize(800, 600)
def open(self):
options = QFileDialog.Options()
# fileName = QFileDialog.getOpenFileName(self, "Open File", QDir.currentPath())
fileName, _ = QFileDialog.getOpenFileName(self, 'QFileDialog.getOpenFileName()', '',
'Images (*.png *.jpeg *.jpg *.bmp *.gif)', options=options)
if fileName:
image = QImage(fileName)
if image.isNull():
QMessageBox.information(self, "Image Viewer", "Cannot load %s." % fileName)
return
self.imageLabel.setPixmap(QPixmap.fromImage(image))
self.scaleFactor = 1.0
self.scrollArea.setVisible(True)
self.printAct.setEnabled(True)
self.fitToWindowAct.setEnabled(True)
self.updateActions()
if not self.fitToWindowAct.isChecked():
self.imageLabel.adjustSize()
def print_(self):
dialog = QPrintDialog(self.printer, self)
if dialog.exec_():
painter = QPainter(self.printer)
rect = painter.viewport()
size = self.imageLabel.pixmap().size()
size.scale(rect.size(), Qt.KeepAspectRatio)
painter.setViewport(rect.x(), rect.y(), size.width(), size.height())
painter.setWindow(self.imageLabel.pixmap().rect())
painter.drawPixmap(0, 0, self.imageLabel.pixmap())
def zoomIn(self):
self.scaleImage(1.25)
def zoomOut(self):
self.scaleImage(0.8)
def normalSize(self):
self.imageLabel.adjustSize()
self.scaleFactor = 1.0
def fitToWindow(self):
fitToWindow = self.fitToWindowAct.isChecked()
self.scrollArea.setWidgetResizable(fitToWindow)
if not fitToWindow:
self.normalSize()
self.updateActions()
def about(self):
QMessageBox.about(self, "About Image Viewer",
"<p>The <b>Image Viewer</b> example shows how to combine "
"QLabel and QScrollArea to display an image. QLabel is "
"typically used for displaying text, but it can also display "
"an image. QScrollArea provides a scrolling view around "
"another widget. If the child widget exceeds the size of the "
"frame, QScrollArea automatically provides scroll bars.</p>"
"<p>The example demonstrates how QLabel's ability to scale "
"its contents (QLabel.scaledContents), and QScrollArea's "
"ability to automatically resize its contents "
"(QScrollArea.widgetResizable), can be used to implement "
"zooming and scaling features.</p>"
"<p>In addition the example shows how to use QPainter to "
"print an image.</p>")
def createActions(self):
self.openAct = QAction("&Open...", self, shortcut="Ctrl+O", triggered=self.open)
self.printAct = QAction("&Print...", self, shortcut="Ctrl+P", enabled=False, triggered=self.print_)
self.exitAct = QAction("E&xit", self, shortcut="Ctrl+Q", triggered=self.close)
self.zoomInAct = QAction("Zoom &In (25%)", self, shortcut="Ctrl++", enabled=False, triggered=self.zoomIn)
self.zoomOutAct = QAction("Zoom &Out (25%)", self, shortcut="Ctrl+-", enabled=False, triggered=self.zoomOut)
self.normalSizeAct = QAction("&Normal Size", self, shortcut="Ctrl+S", enabled=False, triggered=self.normalSize)
self.fitToWindowAct = QAction("&Fit to Window", self, enabled=False, checkable=True, shortcut="Ctrl+F",
triggered=self.fitToWindow)
self.aboutAct = QAction("&About", self, triggered=self.about)
self.aboutQtAct = QAction("About &Qt", self, triggered=qApp.aboutQt)
def createMenus(self):
self.fileMenu = QMenu("&File", self)
self.fileMenu.addAction(self.openAct)
self.fileMenu.addAction(self.printAct)
self.fileMenu.addSeparator()
self.fileMenu.addAction(self.exitAct)
self.viewMenu = QMenu("&View", self)
self.viewMenu.addAction(self.zoomInAct)
self.viewMenu.addAction(self.zoomOutAct)
self.viewMenu.addAction(self.normalSizeAct)
self.viewMenu.addSeparator()
self.viewMenu.addAction(self.fitToWindowAct)
self.helpMenu = QMenu("&Help", self)
self.helpMenu.addAction(self.aboutAct)
self.helpMenu.addAction(self.aboutQtAct)
self.menuBar().addMenu(self.fileMenu)
self.menuBar().addMenu(self.viewMenu)
self.menuBar().addMenu(self.helpMenu)
def updateActions(self):
self.zoomInAct.setEnabled(not self.fitToWindowAct.isChecked())
self.zoomOutAct.setEnabled(not self.fitToWindowAct.isChecked())
self.normalSizeAct.setEnabled(not self.fitToWindowAct.isChecked())
def scaleImage(self, factor):
self.scaleFactor *= factor
self.imageLabel.resize(self.scaleFactor * self.imageLabel.pixmap().size())
self.adjustScrollBar(self.scrollArea.horizontalScrollBar(), factor)
self.adjustScrollBar(self.scrollArea.verticalScrollBar(), factor)
self.zoomInAct.setEnabled(self.scaleFactor < 3.0)
self.zoomOutAct.setEnabled(self.scaleFactor > 0.333)
def adjustScrollBar(self, scrollBar, factor):
scrollBar.setValue(int(factor * scrollBar.value()
+ ((factor - 1) * scrollBar.pageStep() / 2)))
if __name__ == '__main__':
import sys
from PyQt5.QtWidgets import QApplication
app = QApplication(sys.argv)
imageViewer = QImageViewer()
imageViewer.show()
sys.exit(app.exec_())
import cv2
mouse_is_pressing = False
start_x, start_y = -1, -1
def mouse_callback(event, x, y, flags, param):
global start_x, start_y, mouse_is_pressing
img_result = src.copy()
if event == cv2.EVENT_LBUTTONDOWN:
mouse_is_pressing = True
start_x, start_y = x,y
cv2.circle(img_result, (x,y), 10, (0,255,0),-1)
cv2.imshow("img_color", img_result)
elif event == cv2.EVENT_MOUSEMOVE:
if mouse_is_pressing:
cv2.rectangle(img_result, (start_x, start_y), (x,y), (0,255,0), 3)
cv2.imshow("img_color", img_result)
elif event == cv2.EVENT_LBUTTONUP:
mouse_is_pressing = False
img_part = img_result[start_y:y, start_x:x]
cv2.imshow("img_color", img_result)
cv2.imshow("img_part", img_part)
src = cv2.imread("D:/python data/image/image.jpg")
cv2.imshow("img_color", src)
cv2.setMouseCallback("img_color", mouse_callback)
cv2.waitKey(0)
cv2.destroyAllWindows()
在基于QScrollArea的查看器中使用QLabel来实现裁剪变得不必要地复杂，因为该转换很难跟踪，而是使用QGraphicsView，QGraphicsScene和QGraphicsPixmapItem实现相同的逻辑。如下所示，已经实现了很多逻辑：
from PyQt5 import QtCore, QtGui, QtWidgets, QtPrintSupport
class Viewer(QtWidgets.QGraphicsView):
def __init__(self, parent=None):
super().__init__(QtWidgets.QGraphicsScene(), parent)
self.pixmap_item = self.scene().addPixmap(QtGui.QPixmap())
self.setAlignment(QtCore.Qt.AlignTop | QtCore.Qt.AlignLeft)
self.setBackgroundRole(QtGui.QPalette.Dark)
self.setDragMode(QtWidgets.QGraphicsView.RubberBandDrag)
self.rubberBandChanged.connect(self.onRubberBandChanged)
self.last_rect = QtCore.QPointF()
def setPixmap(self, pixmap):
self.pixmap_item.setPixmap(pixmap)
def zoomIn(self):
self.scale(1.25, 1.25)
def zoomOut(self):
self.scale(0.8, 0.8)
def resetZoom(self):
self.resetTransform()
def fitToWindow(self):
self.fitInView(self.pixmap_item)
@QtCore.pyqtSlot(QtCore.QRect, QtCore.QPointF, QtCore.QPointF)
def onRubberBandChanged(self, rubberBandRect, fromScenePoint, toScenePoint):
if rubberBandRect.isNull():
pixmap = self.pixmap_item.pixmap()
rect = self.pixmap_item.mapFromScene(self.last_rect).boundingRect().toRect()
if not rect.intersected(pixmap.rect()).isNull():
crop_pixmap = pixmap.copy(rect)
label = QtWidgets.QLabel(pixmap=crop_pixmap)
dialog = QtWidgets.QDialog(self)
lay = QtWidgets.QVBoxLayout(dialog)
lay.addWidget(label)
dialog.exec_()
self.last_rect = QtCore.QRectF()
else:
self.last_rect = QtCore.QRectF(fromScenePoint, toScenePoint)
class QImageViewer(QtWidgets.QMainWindow):
def __init__(self, parent=None):
super().__init__()
self.view = Viewer()
self.setCentralWidget(self.view)
self.printer = QtPrintSupport.QPrinter()
self.createActions()
self.createMenus()
self.setWindowTitle("Image Viewer")
self.resize(800, 600)
def open(self):
fileName, _ = QtWidgets.QFileDialog.getOpenFileName(
self,
"QFileDialog.getOpenFileName()",
"",
"Images (*.png *.jpeg *.jpg *.bmp *.gif)",
)
if fileName:
pixmap = QtGui.QPixmap(fileName)
if pixmap.isNull():
QtWidgets.QMessageBox.information(
self, "Image Viewer", "Cannot load %s." % fileName
)
return
self.view.setPixmap(pixmap)
self.printAct.setEnabled(True)
self.fitToWindowAct.setEnabled(True)
self.updateActions()
if not self.fitToWindowAct.isChecked():
pass
# self.imageLabel.adjustSize()
def print_(self):
dialog = QtPrintSupport.QPrintDialog(self.printer, self)
if dialog.exec_():
pixmap = self.view.pixmap_item.pixmap()
painter = QtGui.QPainter(self.printer)
rect = painter.viewport()
size = pixmap.size()
size.scale(rect.size(), QtCore.Qt.KeepAspectRatio)
painter.setViewport(rect.x(), rect.y(), size.width(), size.height())
painter.setWindow(pixmap.rect())
painter.drawPixmap(0, 0, pixmap)
def fitToWindow(self):
if self.fitToWindowAct.isChecked():
self.view.fitToWindow()
else:
self.view.resetZoom()
self.updateActions()
def about(self):
QtWidgets.QMessageBox.about(
self,
"About Image Viewer",
"<p>The <b>Image Viewer</b> example shows how to combine "
"QLabel and QScrollArea to display an image. QLabel is "
"typically used for displaying text, but it can also display "
"an image. QScrollArea provides a scrolling view around "
"another widget. If the child widget exceeds the size of the "
"frame, QScrollArea automatically provides scroll bars.</p>"
"<p>The example demonstrates how QLabel's ability to scale "
"its contents (QLabel.scaledContents), and QScrollArea's "
"ability to automatically resize its contents "
"(QScrollArea.widgetResizable), can be used to implement "
"zooming and scaling features.</p>"
"<p>In addition the example shows how to use QPainter to "
"print an image.</p>",
)
def createActions(self):
self.openAct = QtWidgets.QAction(
"&Open...", self, shortcut="Ctrl+O", triggered=self.open
)
self.printAct = QtWidgets.QAction(
"&Print...", self, shortcut="Ctrl+P", enabled=False, triggered=self.print_
)
self.exitAct = QtWidgets.QAction(
"E&xit", self, shortcut="Ctrl+Q", triggered=self.close
)
self.zoomInAct = QtWidgets.QAction(
"Zoom &In (25%)",
self,
shortcut="Ctrl++",
enabled=False,
triggered=self.view.zoomIn,
)
self.zoomOutAct = QtWidgets.QAction(
"Zoom &Out (25%)",
self,
shortcut="Ctrl+-",
enabled=False,
triggered=self.view.zoomOut,
)
self.normalSizeAct = QtWidgets.QAction(
"&Normal Size",
self,
shortcut="Ctrl+S",
enabled=False,
triggered=self.view.resetZoom,
)
self.fitToWindowAct = QtWidgets.QAction(
"&Fit to Window",
self,
enabled=False,
checkable=True,
shortcut="Ctrl+F",
triggered=self.fitToWindow,
)
self.aboutAct = QtWidgets.QAction("&About", self, triggered=self.about)
self.aboutQtAct = QtWidgets.QAction(
"About &Qt", self, triggered=QtWidgets.qApp.aboutQt
)
def createMenus(self):
self.fileMenu = QtWidgets.QMenu("&File", self)
self.fileMenu.addAction(self.openAct)
self.fileMenu.addAction(self.printAct)
self.fileMenu.addSeparator()
self.fileMenu.addAction(self.exitAct)
self.viewMenu = QtWidgets.QMenu("&View", self)
self.viewMenu.addAction(self.zoomInAct)
self.viewMenu.addAction(self.zoomOutAct)
self.viewMenu.addAction(self.normalSizeAct)
self.viewMenu.addSeparator()
self.viewMenu.addAction(self.fitToWindowAct)
self.helpMenu = QtWidgets.QMenu("&Help", self)
self.helpMenu.addAction(self.aboutAct)
self.helpMenu.addAction(self.aboutQtAct)
self.menuBar().addMenu(self.fileMenu)
self.menuBar().addMenu(self.viewMenu)
self.menuBar().addMenu(self.helpMenu)
def updateActions(self):
self.zoomInAct.setEnabled(not self.fitToWindowAct.isChecked())
self.zoomOutAct.setEnabled(not self.fitToWindowAct.isChecked())
self.normalSizeAct.setEnabled(not self.fitToWindowAct.isChecked())
if __name__ == "__main__":
import sys
from PyQt5.QtWidgets import QApplication
app = QApplication(sys.argv)
imageViewer = QImageViewer()
imageViewer.show()
sys.exit(app.exec_())