PyQt5 – 如何从任何图像中创建圆形图像

在这篇文章中，我们将看到如何从任何宽度和高度的图像中只显示圆形/圆形图像，即

为了 做到这一点，我们必须做以下步骤。

1.加载图片

2.裁剪图像，使其成为方形

3.使用Painter将其遮蔽并制作成圆圈

4.将其转换为像素图象

代码。

下面是原始图像：

# importing libraries
from PyQt5.QtCore import * 
from PyQt5.QtGui import * 
from PyQt5.QtWidgets import *
  
# function to alter image
def mask_image(imgdata, imgtype ='png', size = 64):
  
    # Load image
    image = QImage.fromData(imgdata, imgtype)
  
    # convert image to 32-bit ARGB (adds an alpha
    # channel ie transparency factor):
    image.convertToFormat(QImage.Format_ARGB32)
  
    # Crop image to a square:
    imgsize = min(image.width(), image.height())
    rect = QRect(
        (image.width() - imgsize) / 2,
        (image.height() - imgsize) / 2,
        imgsize,
        imgsize,
     )
       
    image = image.copy(rect)
  
    # Create the output image with the same dimensions 
    # and an alpha channel and make it completely transparent:
    out_img = QImage(imgsize, imgsize, QImage.Format_ARGB32)
    out_img.fill(Qt.transparent)
  
    # Create a texture brush and paint a circle 
    # with the original image onto the output image:
    brush = QBrush(image)
  
    # Paint the output image
    painter = QPainter(out_img)
    painter.setBrush(brush)
  
    # Don't draw an outline
    painter.setPen(Qt.NoPen)
  
    # drawing circle
    painter.drawEllipse(0, 0, imgsize, imgsize)
  
    # closing painter event
    painter.end()
  
    # Convert the image to a pixmap and rescale it. 
    pr = QWindow().devicePixelRatio()
    pm = QPixmap.fromImage(out_img)
    pm.setDevicePixelRatio(pr)
    size *= pr
    pm = pm.scaled(size, size, Qt.KeepAspectRatio, 
                               Qt.SmoothTransformation)
  
    # return back the pixmap data
    return pm
  
  
class Window(QWidget):
      
    """Simple window that shows our masked image and text label."""
    def __init__(self):
        super().__init__()
  
        # setting up the geometry
        self.setGeometry(100, 100, 600, 400)
  
        # image path
        imgpath = "image.png"
  
        # loading image
        imgdata = open(imgpath, 'rb').read()
  
        # calling the function
        pixmap = mask_image(imgdata)
  
        # creating label
        self.ilabel = QLabel(self)
  
        # putting image on label
        self.ilabel.setPixmap(pixmap)
  
        # moving the label
        self.ilabel.move(240, 180)
  
        # another label to put text
        self.tlabel = QLabel('This is circular image', self)
        self.tlabel.move(200, 250)
  
  
  
# main function
if __name__ == '__main__':
    import sys
    from PyQt5.QtWidgets import QApplication
  
    # app created
    app = QApplication(sys.argv)
    w = Window()
    w.show()
  
    # begin the app
    sys.exit(app.exec_())

输出 :