以下是一个简单的PyQt5程序,用于绘制图像上的感兴趣区域(ROI)。这个程序使用了QPainter来处理绘图,并且提供了鼠标点击和拖动事件来绘制矩形ROI。
import sys
from PyQt5.QtWidgets import QApplication, QMainWindow, QWidget, QPainter, QMessageBox
from PyQt5.QtCore import Qt, QPoint
from PyQt5.QtGui import QPen, QBrush
 
class ROIWindow(QWidget):
    def __init__(self):
        super().__init__()
        self.initUI()
        self.roi = []
 
    def initUI(self):
        self.setMouseTracking(True)
        self.setMinimumSize(400, 300)
        self.setWindowTitle('ROI Drawer')
 
    def mousePressEvent(self, event):
        if event.button() == Qt.LeftButton:
            self.start = event.pos()
            self.end = self.start
            self.roi.append((self.start, self.end))
            self.update()
 
    def mouseMoveEvent(self, event):
        if event.buttons() & Qt.LeftButton:
            self.end = event.pos()
            self.update()
 
    def paintEvent(self, event):
        painter = QPainter(self)
        painter.setPen(QPen(Qt.red, 1))
        painter.setBrush(QBrush(Qt.transparent))
 
        for i in range(len(self.roi)):
            rect = self.roi[i]
            painter.drawRect(rect[0].x(), rect[0].y(), self.end.x() - rect[0].x(), self.end.y() - rect[0].y())
 
    def keyPressEvent(self, event):
        if event.key() == Qt.Key_Escape:
            self.roi = []
            self.update()
        elif event.key() == Qt.Key_S:
            QMessageBox.information(self, 'ROI', f'ROI count: {len(self.roi)}')
 
def main():
    app = QApplication(sys.argv)
    ex = ROIWindow()
    ex.show()
    sys.exit(app.exec_())
 
if __name__ == '__main__':
    main()这段代码定义了一个名为ROIWindow的类,它继承自QWidget。程序初始化时,会启用鼠标跟踪。鼠标左键点击和移动事件被重写以绘制矩形。按下Esc键将清除所有绘制的ROI,按S键将显示当前ROI的数量。