import cv2

# 打開默認(rèn)攝像頭（通常是0）
cap = cv2.VideoCapture(0)

# 檢查攝像頭是否成功打開
if not cap.isOpened():
    print("無(wú)法打開攝像頭")
    exit()

print("攝像頭已打開，按 'q' 鍵退出")

while True:
    # 讀取一幀
    ret, frame = cap.read()
    
    # 檢查幀是否讀取成功
    if not ret:
        print("無(wú)法讀取幀")
        break
    
    # 顯示幀
    cv2.imshow('攝像頭', frame)
    
    # 按'q'鍵退出
    if cv2.waitKey(1) & 0xFF == ord('q'):
        break

# 釋放資源
cap.release()
cv2.destroyAllWindows()

import cv2

cap = cv2.VideoCapture(0)

# 設(shè)置攝像頭參數(shù)
cap.set(cv2.CAP_PROP_FRAME_WIDTH, 640)   # 寬度
cap.set(cv2.CAP_PROP_FRAME_HEIGHT, 480)  # 高度
cap.set(cv2.CAP_PROP_FPS, 30)            # 幀率

# 獲取實(shí)際參數(shù)值
width = cap.get(cv2.CAP_PROP_FRAME_WIDTH)
height = cap.get(cv2.CAP_PROP_FRAME_HEIGHT)
fps = cap.get(cv2.CAP_PROP_FPS)

print(f"攝像頭分辨率: {width}x{height}, 幀率: {fps}")

while True:
    ret, frame = cap.read()
    if not ret:
        break
    
    # 在畫面上顯示信息
    cv2.putText(frame, f"分辨率: {int(width)}x{int(height)}", (10, 30), 
                cv2.FONT_HERSHEY_SIMPLEX, 0.7, (0, 255, 0), 2)
    cv2.putText(frame, f"幀率: {fps}", (10, 60), 
                cv2.FONT_HERSHEY_SIMPLEX, 0.7, (0, 255, 0), 2)
    
    cv2.imshow('攝像頭', frame)
    
    if cv2.waitKey(1) & 0xFF == ord('q'):
        break

cap.release()
cv2.destroyAllWindows()

import cv2

# 嘗試打開多個(gè)攝像頭
caps = []
for i in range(3):  # 嘗試打開0,1,2號(hào)攝像頭
    cap = cv2.VideoCapture(i)
    if cap.isOpened():
        caps.append(cap)
        print(f"攝像頭 {i} 已連接")
    else:
        print(f"攝像頭 {i} 未連接")

if not caps:
    print("沒有可用的攝像頭")
    exit()

print(f"共找到 {len(caps)} 個(gè)攝像頭")

while True:
    frames = []
    for i, cap in enumerate(caps):
        ret, frame = cap.read()
        if ret:
            # 在每幀上標(biāo)記攝像頭編號(hào)
            cv2.putText(frame, f"Camera {i}", (10, 30), 
                        cv2.FONT_HERSHEY_SIMPLEX, 1, (0, 255, 0), 2)
            frames.append(frame)
    
    if not frames:
        break
    
    # 合并顯示多個(gè)攝像頭畫面
    if len(frames) == 1:
        combined = frames[0]
    elif len(frames) == 2:
        combined = cv2.hconcat(frames)
    else:
        # 對(duì)于3個(gè)或更多攝像頭，可以調(diào)整布局
        top = cv2.hconcat(frames[:2])
        bottom = cv2.hconcat(frames[2:]) if len(frames) > 2 else frames[2]
        combined = cv2.vconcat([top, bottom]) if len(frames) > 2 else top
    
    cv2.imshow('多攝像頭', combined)
    
    if cv2.waitKey(1) & 0xFF == ord('q'):
        break

# 釋放所有攝像頭
for cap in caps:
    cap.release()
cv2.destroyAllWindows()

import cv2

cap = cv2.VideoCapture(0)

# 設(shè)置視頻編碼器和輸出文件
fourcc = cv2.VideoWriter_fourcc(*'XVID')
out = cv2.VideoWriter('output.avi', fourcc, 20.0, (640, 480))

recording = False
print("按 'r' 開始/停止錄制，按 'q' 退出")

while True:
    ret, frame = cap.read()
    if not ret:
        break
    
    # 如果正在錄制，保存幀
    if recording:
        out.write(frame)
        cv2.putText(frame, "錄制中...", (10, 30), 
                    cv2.FONT_HERSHEY_SIMPLEX, 1, (0, 0, 255), 2)
    
    cv2.imshow('攝像頭', frame)
    
    key = cv2.waitKey(1) & 0xFF
    if key == ord('q'):
        break
    elif key == ord('r'):
        recording = not recording
        print("錄制" if recording else "停止錄制")

cap.release()
out.release()  # 釋放視頻寫入器
cv2.destroyAllWindows()

import cv2
import numpy as np

cap = cv2.VideoCapture(0)

mode = 0  # 0: 原圖, 1: 灰度, 2: 邊緣檢測(cè), 3: 模糊
modes = ['原圖', '灰度', '邊緣檢測(cè)', '模糊']

print("按 'm' 切換模式，按 'q' 退出")

while True:
    ret, frame = cap.read()
    if not ret:
        break
    
    # 根據(jù)模式處理圖像
    if mode == 1:
        processed = cv2.cvtColor(frame, cv2.COLOR_BGR2GRAY)
        processed = cv2.cvtColor(processed, cv2.COLOR_GRAY2BGR)  # 轉(zhuǎn)回BGR用于顯示
    elif mode == 2:
        gray = cv2.cvtColor(frame, cv2.COLOR_BGR2GRAY)
        processed = cv2.Canny(gray, 100, 200)
        processed = cv2.cvtColor(processed, cv2.COLOR_GRAY2BGR)
    elif mode == 3:
        processed = cv2.GaussianBlur(frame, (15, 15), 0)
    else:
        processed = frame.copy()
    
    # 顯示當(dāng)前模式
    cv2.putText(processed, f"模式: {modes[mode]}", (10, 30), 
                cv2.FONT_HERSHEY_SIMPLEX, 0.7, (0, 255, 0), 2)
    
    cv2.imshow('攝像頭', processed)
    
    key = cv2.waitKey(1) & 0xFF
    if key == ord('q'):
        break
    elif key == ord('m'):
        mode = (mode + 1) % len(modes)
        print(f"切換到模式: {modes[mode]}")

cap.release()
cv2.destroyAllWindows()

# 顯示一幀圖像
    cv2.imshow('frame', frame)

    # 如果按下'q'鍵，退出循環(huán)
    if cv2.waitKey(1) & 0xFF == ord('q'):
        break