OpenCV-Python系列·第十九集-1：视频处理（negative film）

最新推荐文章于 2024-03-23 11:56:03 发布

Seung-Yim Yau

最新推荐文章于 2024-03-23 11:56:03 发布

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分类专栏： OpenCV-Python

本文链接：https://blog.youkuaiyun.com/Miracle0_0/article/details/82082286

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博客介绍了利用鼠标事件绘制矩形框，并对框内像素点进行反转的操作，涉及信息技术中图形绘制与像素处理相关内容。

Tip：应用鼠标事件画出一个矩形框，再对像素点进行反转

# -*- coding: utf-8 -*-
"""
Created on Sun Aug 26 16:30:20 2018

@author: Miracle
"""

import cv2

def drawRectangle(event,x,y,flags,params):
    global init_x,init_y,drawing,point_top_left,point_bottom_right
    #鼠标响应
    if event == cv2.EVENT_LBUTTONDOWN:
        drawing = True
        init_x,init_y = x,y
    elif event == cv2.EVENT_MOUSEMOVE:
        if drawing:
            point_top_left = (min(init_x,x),min(init_y,y))
            point_bottom_right = (max(init_x,x),max(init_y,y))
            image[init_y:y,init_x:x] = 255 - image[init_y:y,init_x:x]
    elif event == cv2.EVENT_LBUTTONUP:
        drawing = False
        point_top_left = (min(init_x,x),min(init_y,y))
        point_bottom_right = (max(init_x,x),max(init_y,y))
        image[init_y:y,init_x:x] = 255 - image[init_y:y,init_x:x]

if __name__ == '__main__':
    drawing = False
    point_bottom_right,point_top_left = (-1,-1),(-1,-1)
    
    cap = cv2.VideoCapture(0)
    
    if not cap.isOpened():
        raise IOError('Cannot open webcam!')
    
    cv2.namedWindow('webcam')
    cv2.setMouseCallback('webcam',drawRectangle)
    
    while True:
        ret,frame = cap.read()
        image = cv2.resize(frame,None,fx = 1.25,fy = 1.25,
                           interpolation = cv2.INTER_LINEAR)
        
        (x0,y0),(x1,y1) = point_top_left,point_bottom_right
        image[y0:y1,x0:x1] = 255 - image[y0:y1,x0:x1] 
        cv2.imshow('webcam',image)
        
        key = cv2.waitKey(1)
        if key == 27:
            break
    
    cap.release()
    cv2.destroyAllWindows()