python pyqt5 显示opencv mat格式的图像

记录一下：

 def show_img(self, mat):
        # cv2.imwrite("5.jpg", data)  # ok
        self.label.clear()
        if mat is not None:
            # image_height, image_width = mat.shape  # 读取图像高宽深度
            # print("he", image_height)
            # print("wi", image_width)
            # qim = QImage(mat.data, image_width, image_height,  image_width * 3, QImage.Format_RGB888) #  彩色图像
            qim = QImage(mat[:], mat.shape[1], mat.shape[0], QImage.Format_Indexed8)  # 灰度图像

            pix = QPixmap(qim).scaled(self.label.width(), self.label.height())

            self.label.setPixmap(pix)

            self.label.setScaledContents(True)