Python使用OpenCV实现帧间差异检测

import cv2
import numpy as np
 
class FrameObject:
    def __init__(self):
        self.prev_frame = None
        self.color_list = [(0, 255, 0), (0, 0, 255), (255, 0, 0), (0, 255, 255), (255, 255, 0)]  # 预定义几种颜色
 
    def init_parameters(self, *args, **kwargs):
        pass
 
    def get_complementary_color(self, color):
        """计算互补色"""
        return (255 - color[0], 255 - color[1], 255 - color[2])
 
    def do(self, frame, device):
        # 转换为灰度图像
        gray_frame = cv2.cvtColor(frame, cv2.COLOR_BGR2GRAY)
 
        # 如果是第一次处理，保存当前帧并返回原图
        if self.prev_frame is None:
            self.prev_frame = gray_frame
            return frame
 
        # 计算当前帧和上一帧的差异
        diff = cv2.absdiff(self.prev_frame, gray_frame)
 
        # 对差异图像应用阈值，以突出显示变化区域
        _, thresh = cv2.threshold(diff, 25, 255, cv2.THRESH_BINARY)
 
        # 找到轮廓，标识出变化的区域
        contours, _ = cv2.findContours(thresh, cv2.RETR_EXTERNAL, cv2.CHAIN_APPROX_SIMPLE)
 
        color_idx = 0  # 颜色索引
 
        # 在原始图像上绘制变化区域的轮廓
        for contour in contours:
            if cv2.contourArea(contour) > 500:  # 过滤掉小的变化区域
                (x, y, w, h) = cv2.boundingRect(contour)
                color = self.color_list[color_idx % len(self.color_list)]  # 循环使用颜色
                complementary_color = self.get_complementary_color(color)  # 获取对比色
 
                # 使用不同的颜色绘制矩形框
                cv2.rectangle(frame, (x, y), (x + w, y + h), color, 2)
                
                # 绘制轮廓边界使用对比色
                cv2.drawContours(frame, [contour], -1, complementary_color, 2)
 
                # 增加颜色索引，以便为下一个变化区域使用不同颜色
                color_idx += 1
 
        # 更新上一帧
        self.prev_frame = gray_frame
 
        return frame

gray_frame = cv2.cvtColor(frame, cv2.COLOR_BGR2GRAY)

diff = cv2.absdiff(self.prev_frame, gray_frame)

_, thresh = cv2.threshold(diff, 25, 255, cv2.THRESH_BINARY)

contours, _ = cv2.findContours(thresh, cv2.RETR_EXTERNAL, cv2.CHAIN_APPROX_SIMPLE)

cv2.rectangle(frame, (x, y), (x + w, y + h), color, 2) cv2.drawContours(frame, [contour], -1, complementary_color, 2)