一、创建一个 PyQt 应用程序,该应用程序能够:
- 使用 OpenCV 加载一张图像。
- 在 PyQt 的窗口中显示这张图像。
- 提供四个按钮(QPushButton):
- 一个用于将图像转换为灰度图
- 一个用于将图像恢复为原始彩色图
- 一个用于将图像进行翻转
- 一个用于将图像进行旋转
- 4.当用户点击按钮时,相应地更新窗口中显示的图像。
import sys
import cv2
from PyQt6.QtGui import QImage, QPixmap
from PyQt6.QtWidgets import QWidget, QApplication, QLabel, QPushButton
from PyQt6 import uic# 封装一个我的窗口类
class MyWidget(QWidget):def __init__(self):super().__init__()# 通过 uic 将 ui 界面加载到程序中来ui = uic.loadUi("./form.ui", self)# 加载图像self.original_image = cv2.imread("../images/lena.png")if self.original_image is None:print("无法加载图像,请检查图像路径。")sys.exit(1)self.current_image = self.original_image.copy()self.label: QLabel = ui.labelself.btn1: QPushButton = ui.btn1self.btn2: QPushButton = ui.btn2self.btn3: QPushButton = ui.btn3self.btn4: QPushButton = ui.btn4# 显示原始图像self.display_image(self.current_image)self.label.setScaledContents(True)# 连接按钮信号和槽函数self.btn1.clicked.connect(self.convert_to_gray)self.btn2.clicked.connect(self.restore_color)self.btn3.clicked.connect(self.flip_image)self.btn4.clicked.connect(self.rotate_image)def display_image(self, image):height, width, channel = image.shapebytes_per_line = 3 * widthq_img = QImage(image.data, width, height, bytes_per_line, QImage.Format.Format_BGR888)pixmap = QPixmap.fromImage(q_img)self.label.setPixmap(pixmap)def convert_to_gray(self):self.current_image = cv2.cvtColor(self.current_image, cv2.COLOR_BGR2GRAY)self.current_image = cv2.cvtColor(self.current_image, cv2.COLOR_GRAY2BGR)self.display_image(self.current_image)def restore_color(self):self.current_image = self.original_image.copy()self.display_image(self.current_image)def flip_image(self):self.current_image = cv2.flip(self.current_image, 1)self.display_image(self.current_image)def rotate_image(self):self.current_image = cv2.rotate(self.current_image, cv2.ROTATE_90_CLOCKWISE)self.display_image(self.current_image)if __name__ == '__main__':app = QApplication(sys.argv)myWidget = MyWidget()myWidget.show()sys.exit(app.exec())
结果展示:
二、创建一个 PyQt 应用程序,该应用程序能够:
- 使用 OpenCV 加载一张彩色图像,并在 PyQt 的窗口中显示它。
- 提供一个滑动条(QSlider),允许用户调整图像的亮度。
- 当用户调整滑动条时,实时更新窗口中显示的图像亮度。
- 添加另一个滑动条(QSlider),允许用户调整图像的对比度。
- 当用户调整滚动条时,实时更新窗口中显示的图像对比度。
- 提供一个按钮(QPushButton),允许用户将图像保存为新的文件。
- 当用户点击保存按钮时,将调整后的图像保存到指定的路径,OpenCV中使用cv2.imwrite()来保存图片。
import sys
import cv2
from PyQt6.QtGui import QImage, QPixmap
from PyQt6.QtWidgets import QWidget, QApplication, QLabel, QPushButton, QSlider, QFileDialog
from PyQt6 import uicclass MyWidget(QWidget):def __init__(self):super().__init__()# 通过 uic 将 ui 界面加载到程序中来ui = uic.loadUi("./form1.ui", self)self.original_image = cv2.imread("../images/lena.png")if self.original_image is None:print("无法加载图像,请检查图像路径。")sys.exit(1)self.current_image = self.original_image.copy()self.label: QLabel = ui.labelself.Slider1: QSlider = ui.Slider1self.Slider2: QSlider = ui.Slider2self.pushButton: QPushButton = ui.pushButton# 初始化滑动条范围self.Slider1.setRange(-100, 100)self.Slider2.setRange(0, 200)self.Slider1.setValue(0)self.Slider2.setValue(100)# 连接信号和槽self.Slider1.valueChanged.connect(self.adjust_brightness)self.Slider2.valueChanged.connect(self.adjust_contrast)self.pushButton.clicked.connect(self.save_image)self.display_image(self.current_image)self.label.setScaledContents(True)def display_image(self, image):height, width, channel = image.shapebytes_per_line = 3 * widthq_img = QImage(image.data, width, height, bytes_per_line, QImage.Format.Format_BGR888)pixmap = QPixmap.fromImage(q_img)self.label.setPixmap(pixmap)def adjust_brightness(self, value):# 调整亮度alpha = 1.0beta = valueself.current_image = cv2.convertScaleAbs(self.original_image, alpha=alpha, beta=beta)self.display_image(self.current_image)def adjust_contrast(self, value):# 调整对比度alpha = value / 100.0beta = 0self.current_image = cv2.convertScaleAbs(self.original_image, alpha=alpha, beta=beta)self.display_image(self.current_image)def save_image(self):# 选择保存路径file_path, _ = QFileDialog.getSaveFileName(self, "保存图像", "", "图像文件 (*.png *.jpg *.jpeg)")if file_path:try:cv2.imwrite(file_path, self.current_image)print(f"图像已保存到 {file_path}")except Exception as e:print(f"保存图像时出错: {e}")if __name__ == '__main__':app = QApplication(sys.argv)myWidget = MyWidget()myWidget.show()sys.exit(app.exec())
结果展示:
三、创建一个 PyQt 应用程序,该应用程序能够:
- 使用 OpenCV 加载一张图像。
- 在 PyQt 的窗口中显示这张图像。
- 提供一个下拉列表(QComboBox),对图像做(模糊、锐化、边缘检测)处理:
- 模糊——使用cv2.GaussianBlur()实现
- 锐化——使用cv2.Laplacian()、cv2.Sobel()实现
- 边缘检测——使用cv2.Canny()实现
- 当用户点击下拉列表选项时,相应地更新窗口中显示的图像。
- 提供一个按钮,当用户点击按钮时,能保存调整后的图像。
import sys
import cv2
from PyQt6.QtGui import QImage, QPixmap
from PyQt6.QtWidgets import QWidget, QApplication, QLabel, QPushButton, QSlider, QFileDialog, QComboBox
from PyQt6 import uic# 封装一个我的窗口类
class MyWidget(QWidget):def __init__(self):super().__init__()# 通过uic将ui界面加载到程序中来ui = uic.loadUi("./form2.ui",self)self.original_image = cv2.imread("../images/lena.png")if self.original_image is None:print("无法加载图像,请检查图像路径。")sys.exit(1)self.current_image = self.original_image.copy()self.label: QLabel = ui.labelself.comboBox:QComboBox = ui.comboBoxself.pushButton:QPushButton = ui.pushButtonself.comboBox.addItems(["原始图像","模糊处理","锐化处理","边缘检测"])self.display_image(self.current_image)self.label.setScaledContents(True)self.comboBox.currentIndexChanged.connect(self.comboBox_slot)self.pushButton.clicked.connect(self.save_image)def display_image(self, image):height, width, channel = image.shapebytes_per_line = 3 * widthq_img = QImage(image.data, width, height, bytes_per_line, QImage.Format.Format_BGR888)pixmap = QPixmap.fromImage(q_img)self.label.setPixmap(pixmap)def comboBox_slot(self):if self.comboBox.currentText() == "原始图像":self.current_image = self.original_image.copy()elif self.comboBox.currentText() == "模糊处理":self.current_image = cv2.GaussianBlur(self.original_image,(5,5),0)elif self.comboBox.currentText() == "锐化处理":laplacian = cv2.Laplacian(self.original_image,cv2.CV_64F)self.current_image = cv2.convertScaleAbs(laplacian)elif self.comboBox.currentText() == "边缘检测":# 使用 Canny 边缘检测self.current_image = cv2.Canny(self.original_image, 100, 200)# 转换为三通道图像以便显示self.current_image = cv2.cvtColor(self.current_image, cv2.COLOR_GRAY2BGR)self.display_image(self.current_image)def save_image(self):# 选择保存路径file_path, _ = QFileDialog.getSaveFileName(self, "保存图像", "", "图像文件 (*.png *.jpg *.jpeg)")if file_path:try:cv2.imwrite(file_path, self.current_image)print(f"图像已保存到 {file_path}")except Exception as e:print(f"保存图像时出错: {e}")if __name__ == '__main__':app = QApplication(sys.argv)myWidget = MyWidget()myWidget.show()sys.exit(app.exec())
结果展示:
四、请编写一段Python代码,实现以下功能:
- 读取一张二维码图片
- 进行二值化处理和形态学操作,获取二维码轮廓
- 通过轮廓外接特征检测或者多边形逼近等获取 二维码的四个点
- 进行透视变换,矫正二维码图像
import cv2
import numpy as npdef order_points(pts):"""对四个点进行排序:左上,右上,右下,左下"""rect = np.zeros((4, 2), dtype="float32")s = pts.sum(axis=1)rect[0] = pts[np.argmin(s)] # 左上(x+y最小)rect[2] = pts[np.argmax(s)] # 右下(x+y最大)diff = np.diff(pts, axis=1)rect[1] = pts[np.argmin(diff)] # 右上(y-x最小)rect[3] = pts[np.argmax(diff)] # 左下(y-x最大)return rect# 1. 读取图片
image = cv2.imread('../images/erwei.jpg')
image = cv2.resize(image,(0,0),fx=0.5,fy=0.5)
orig = image.copy()# 2. 预处理
gray = cv2.cvtColor(image, cv2.COLOR_BGR2GRAY)
blur = cv2.GaussianBlur(gray, (5, 5), 0)
_, thresh = cv2.threshold(blur, 127, 255, cv2.THRESH_BINARY + cv2.THRESH_OTSU)# 形态学操作(闭运算填充内部空隙)
kernel = np.ones((3, 3), np.uint8)
closed = cv2.morphologyEx(thresh, cv2.MORPH_CLOSE, kernel, iterations=2)# 3. 轮廓检测
contours, _ = cv2.findContours(closed, cv2.RETR_EXTERNAL, cv2.CHAIN_APPROX_SIMPLE)# 筛选最大轮廓并进行多边形逼近
max_area = 0
screen_pts = None
for cnt in contours:area = cv2.contourArea(cnt)if area < 1000: # 过滤小面积噪声continueperi = cv2.arcLength(cnt, True)approx = cv2.approxPolyDP(cnt, 0.02 * peri, True)if len(approx) == 4:if area > max_area:max_area = areascreen_pts = approx.reshape(4, 2)if screen_pts is None:raise ValueError("未检测到二维码轮廓")# 4. 透视变换
rect = order_points(screen_pts)
(tl, tr, br, bl) = rect# 计算目标图像尺寸
width_a = np.linalg.norm(br - bl)
width_b = np.linalg.norm(tr - tl)
max_width = max(int(width_a), int(width_b))height_a = np.linalg.norm(tr - br)
height_b = np.linalg.norm(tl - bl)
max_height = max(int(height_a), int(height_b))# 目标点坐标
dst = np.array([[0, 0],[max_width - 1, 0],[max_width - 1, max_height - 1],[0, max_height - 1]], dtype="float32")# 计算变换矩阵并执行变换
M = cv2.getPerspectiveTransform(rect, dst)
warped = cv2.warpPerspective(orig, M, (max_width, max_height))# 显示结果
cv2.imshow("Original", orig)
cv2.imshow("Corrected QR Code", warped)
cv2.waitKey(0)
cv2.destroyAllWindows()
五、 请编写一段Python代码,实现以下功能:
- 读取一张彩色图像
- 制作要提取颜色的掩膜
- 输出抠图后的前景图 和 背景图
import cv2
import numpy as npdef extract_colors(image_path):# 1. 读取彩色图像img = cv2.imread(image_path)hsv = cv2.cvtColor(img, cv2.COLOR_BGR2HSV)# 2. 定义颜色范围(示例:提取红色系)# 可根据需求修改阈值范围lower_red1 = np.array([0, 43, 46]) # 红色HSV下限1upper_red1 = np.array([10, 255, 255]) # 红色HSV上限1lower_red2 = np.array([156, 43, 46]) # 红色HSV下限2(处理色相环闭合)upper_red2 = np.array([180, 255, 255]) # 红色HSV上限2# 生成掩膜mask1 = cv2.inRange(hsv, lower_red1, upper_red1)mask2 = cv2.inRange(hsv, lower_red2, upper_red2)mask = cv2.bitwise_or(mask1, mask2)# 形态学优化(填充空洞、去除噪声)kernel = np.ones((5,5), np.uint8)mask = cv2.morphologyEx(mask, cv2.MORPH_CLOSE, kernel, iterations=2)mask = cv2.morphologyEx(mask, cv2.MORPH_OPEN, kernel, iterations=1)# 3. 分割前景和背景foreground = cv2.bitwise_and(img, img, mask=mask)background = cv2.bitwise_and(img, img, mask=cv2.bitwise_not(mask))# 4. 显示结果# cv2.imshow("Original", img)cv2.imshow("Foreground", foreground)cv2.imshow("Background", background)cv2.waitKey(0)cv2.destroyAllWindows()# 执行函数(替换为你的图片路径)
extract_colors("../images/redflowers.png")
结果展示: