根据任何图像几何调整GraphicView

Question

我的 QGraphicsView 应该显示一个大分辨率的图像。大小应适合可调整大小的窗口。目前，图像以我想要的方式查看，但只能通过为初始视图几何图形提供一些手动调整的值。这看起来不整洁。我也尝试参考这里发布的解决方案：Graphics View and Pixmap Size

我当前的窗口是这样的：

class ImageCheck(Ui_ImageCheck.Ui_MainWindow, QMainWindow):
    def __init__(self, parent=None):
        super(ImageCheck, self).__init__()
        self.setupUi(self)
        self.setWindowTitle("Image Analyzer")

        self.crop_ratio_w = 1
        self.crop_ratio_h = 1

        self.path = None
        self.scene = QGraphicsScene()
        self.scene.clear()
        self.image_item = QGraphicsPixmapItem()
        # This is the approximate shift in coordinates of my initial view from the window
        self.view.setGeometry(self.geometry().x()+ 10, self.geometry().y()+ 39, 
                    self.geometry().width()- 55, self.geometry().height()- 110)

        self.view.setAlignment(Qt.AlignCenter)
        self.view.setFrameShape(QFrame.NoFrame)

        def setImage(self, path):
           self.path = path
           self.crop_ratio_w = self.pixmap.width() / self.view.width()
           self.crop_ratio_h = self.pixmap.height() / self.view.height()

           pixmap = QPixmap(path)
           smaller_pixmap = pixmap.scaled(self.view.width(), self.view.height(),
                    Qt.IgnoreAspectRatio, t.FastTransformation)

           self.image_item.setPixmap(smaller_pixmap)
           self.scene.addItem(self.image_item)

           self.scene.setSceneRect(0, 0, self.view.width(), self.view.height())
           self.view.setGeometry(0, 0, self.view.width(), self.view.height())   

           self.view.setVerticalScrollBarPolicy(Qt.ScrollBarAlwaysOff)
           self.view.setHorizontalScrollBarPolicy(Qt.ScrollBarAlwaysOff)
           self.view.setScene(self.scene)
           self.view.setSceneSize()

        def resizeEvent(self, event):
           self.view.setGeometry(self.geometry().x()+ 10, self.geometry().y()+ 39, 
                    self.geometry().width()- 55, self.geometry().height()- 110)
           self.setImage(self.path)

当我试图确定两点之间的距离时，我的手动覆盖可能不是一个好主意。即使是按比例缩放的距离也给了我一个稍微错误的值。

Answer 1

我不能使用你的代码，因为有很多隐藏的东西，所以我将提出下一个解决方案，即每次窗口改变大小时根据场景重新缩放视图。我还实现了一个信号，根据图像的坐标传输图像中的点击信息。

from PyQt5 import QtCore, QtGui, QtWidgets


class ClickableGraphicsView(QtWidgets.QGraphicsView):
    clicked = QtCore.pyqtSignal(QtCore.QPoint)

    def __init__(self, parent=None):
        super(ClickableGraphicsView, self).__init__(parent)
        scene = QtWidgets.QGraphicsScene(self)
        self.setScene(scene)
        self.pixmap_item = None

    def setImage(self, path):
        pixmap = QtGui.QPixmap(path)
        self.pixmap_item = self.scene().addPixmap(pixmap)
        self.pixmap_item.setShapeMode(
            QtWidgets.QGraphicsPixmapItem.BoundingRectShape
        )

    def mousePressEvent(self, event):
        if self.pixmap_item is not None:
            if self.pixmap_item == self.itemAt(event.pos()):
                sp = self.mapToScene(event.pos())
                lp = self.pixmap_item.mapToItem(self.pixmap_item, sp)
                p = lp.toPoint()
                if self.pixmap_item.pixmap().rect().contains(p):
                    self.clicked.emit(p)
        super(ClickableGraphicsView, self).mousePressEvent(event)

    def resizeEvent(self, event):
        self.fitInView(self.sceneRect(), QtCore.Qt.IgnoreAspectRatio)
        super(ClickableGraphicsView, self).resizeEvent(event)


class MainWindow(QtWidgets.QMainWindow):
    def __init__(self, parent=None):
        super(MainWindow, self).__init__(parent)
        self.setWindowTitle("Image Analyzer")
        view = ClickableGraphicsView()
        view.clicked.connect(print)
        view.setImage("image.jpg")

        label = QtWidgets.QLabel("Distance")
        display = QtWidgets.QLCDNumber()

        buttonbox = QtWidgets.QDialogButtonBox(
            QtWidgets.QDialogButtonBox.Ok | QtWidgets.QDialogButtonBox.Cancel
        )

        widget = QtWidgets.QWidget()
        self.setCentralWidget(widget)
        lay = QtWidgets.QGridLayout(widget)
        lay.addWidget(view, 0, 0, 1, 2)
        hlay = QtWidgets.QHBoxLayout()
        hlay.addWidget(label)
        hlay.addWidget(display)
        hlay.addStretch()
        lay.addLayout(hlay, 1, 0)
        lay.addWidget(buttonbox, 1, 1)


if __name__ == "__main__":
    import sys

    app = QtWidgets.QApplication(sys.argv)
    w = MainWindow()
    w.show()
    sys.exit(app.exec_())