# Python + OpenCV 示例代碼
import cv2
import numpy as np

# 讀取圖像
image = cv2.imread('example.jpg')

# 顯示圖像信息
print(f"圖像形狀: {image.shape}")
print(f"圖像類型: {image.dtype}")
print(f"圖像大小: {image.size} bytes")

# 顯示圖像
cv2.imshow('Image', image)
cv2.waitKey(0)
cv2.destroyAllWindows()

┌─────────────────────────────────────────────────────────┐
│                  計(jì)算機(jī)視覺技術(shù)棧                        │
├─────────────────────────────────────────────────────────┤
│  ┌─────────────┐  ┌─────────────┐  ┌─────────────┐     │
│  │  圖像獲取   │  │  圖像處理   │  │  特征提取   │     │
│  │  (Camera)   │  │  (Process)  │  │  (Feature)  │     │
│  └─────────────┘  └─────────────┘  └─────────────┘     │
│         ↑                                    ↓          │
│  ┌─────────────────────────────────────────────────┐   │
│  │              深度學(xué)習(xí)模型 (CNN/Transformer)       │   │
│  └─────────────────────────────────────────────────┘   │
└─────────────────────────────────────────────────────────┘

import cv2
import numpy as np

class ImageProcessor:
    """圖像處理示例類"""
    
    def __init__(self, image_path):
        """
        初始化圖像處理器
        
        Args:
            image_path: 圖像文件路徑
        """
        self.image = cv2.imread(image_path)
        if self.image is None:
            raise ValueError(f"無法讀取圖像: {image_path}")
        
        self.height, self.width = self.image.shape[:2]
        print(f"圖像尺寸: {self.width} x {self.height}")
    
    def to_grayscale(self):
        """轉(zhuǎn)換為灰度圖"""
        return cv2.cvtColor(self.image, cv2.COLOR_BGR2GRAY)
    
    def resize(self, scale_percent):
        """按比例縮放圖像"""
        width = int(self.width * scale_percent / 100)
        height = int(self.height * scale_percent / 100)
        return cv2.resize(self.image, (width, height))
    
    def apply_gaussian_blur(self, kernel_size=(5, 5)):
        """應(yīng)用高斯模糊"""
        return cv2.GaussianBlur(self.image, kernel_size, 0)
    
    def detect_edges(self, threshold1=100, threshold2=200):
        """邊緣檢測"""
        gray = self.to_grayscale()
        return cv2.Canny(gray, threshold1, threshold2)

# 使用示例
if __name__ == "__main__":
    processor = ImageProcessor("example.jpg")
    
    # 灰度轉(zhuǎn)換
    gray = processor.to_grayscale()
    cv2.imwrite("gray.jpg", gray)
    
    # 邊緣檢測
    edges = processor.detect_edges()
    cv2.imwrite("edges.jpg", edges)

# 創(chuàng)建虛擬環(huán)境
python -m venv cv_env
source cv_env/bin/activate  # Linux/Mac
# 或 cv_env\Scripts\activate  # Windows

# 安裝OpenCV
pip install opencv-python
pip install opencv-contrib-python  # 包含額外模塊

# 安裝其他常用庫
pip install numpy matplotlib pillow

# 驗(yàn)證安裝
python -c "import cv2; print(cv2.__version__)"

# 檢查環(huán)境配置
import cv2
import numpy as np
import matplotlib.pyplot as plt

print(f"OpenCV版本: {cv2.__version__}")
print(f"NumPy版本: {np.__version__}")

# 檢查是否支持GPU
print(f"CUDA支持: {cv2.cuda.getCudaEnabledDeviceCount()}")

import cv2
import numpy as np

# 讀取圖像
image = cv2.imread('image.jpg')

# 檢查是否成功讀取
if image is None:
    print("錯(cuò)誤：無法讀取圖像")
else:
    # 顯示圖像信息
    print(f"圖像尺寸: {image.shape}")
    print(f"數(shù)據(jù)類型: {image.dtype}")
    
    # 顯示圖像
    cv2.imshow('Original Image', image)
    
    # 轉(zhuǎn)換為灰度圖
    gray = cv2.cvtColor(image, cv2.COLOR_BGR2GRAY)
    cv2.imshow('Gray Image', gray)
    
    # 等待按鍵
    cv2.waitKey(0)
    cv2.destroyAllWindows()

import cv2
import numpy as np

def process_image(image_path):
    """完整的圖像處理流程"""
    
    # 1. 讀取圖像
    image = cv2.imread(image_path)
    if image is None:
        raise ValueError("無法讀取圖像")
    
    # 2. 轉(zhuǎn)換為灰度圖
    gray = cv2.cvtColor(image, cv2.COLOR_BGR2GRAY)
    
    # 3. 高斯模糊去噪
    blurred = cv2.GaussianBlur(gray, (5, 5), 0)
    
    # 4. 邊緣檢測
    edges = cv2.Canny(blurred, 50, 150)
    
    # 5. 查找輪廓
    contours, _ = cv2.findContours(edges, cv2.RETR_EXTERNAL, cv2.CHAIN_APPROX_SIMPLE)
    
    # 6. 繪制輪廓
    result = image.copy()
    cv2.drawContours(result, contours, -1, (0, 255, 0), 2)
    
    print(f"檢測到 {len(contours)} 個(gè)輪廓")
    
    return result

# 使用示例
result = process_image('objects.jpg')
cv2.imshow('Result', result)
cv2.waitKey(0)
cv2.destroyAllWindows()

import cv2
import numpy as np

class FeatureDetector:
    """特征檢測器類"""
    
    def __init__(self):
        # 初始化ORB檢測器
        self.orb = cv2.ORB_create()
        # 初始化SIFT檢測器（需要opencv-contrib-python）
        # self.sift = cv2.SIFT_create()
    
    def detect_and_compute(self, image):
        """檢測關(guān)鍵點(diǎn)并計(jì)算描述子"""
        keypoints, descriptors = self.orb.detectAndCompute(image, None)
        return keypoints, descriptors
    
    def match_features(self, img1, img2):
        """特征匹配"""
        # 檢測特征點(diǎn)
        kp1, des1 = self.detect_and_compute(img1)
        kp2, des2 = self.detect_and_compute(img2)
        
        # 創(chuàng)建匹配器
        bf = cv2.BFMatcher(cv2.NORM_HAMMING, crossCheck=True)
        
        # 匹配特征點(diǎn)
        matches = bf.match(des1, des2)
        
        # 按距離排序
        matches = sorted(matches, key=lambda x: x.distance)
        
        # 繪制匹配結(jié)果
        result = cv2.drawMatches(img1, kp1, img2, kp2, matches[:20], None, flags=2)
        
        return result, len(matches)
    
    def find_homography(self, img1, img2):
        """計(jì)算單應(yīng)性矩陣"""
        kp1, des1 = self.detect_and_compute(img1)
        kp2, des2 = self.detect_and_compute(img2)
        
        bf = cv2.BFMatcher(cv2.NORM_HAMMING)
        matches = bf.knnMatch(des1, des2, k=2)
        
        # 應(yīng)用比率測試
        good = []
        for m, n in matches:
            if m.distance < 0.75 * n.distance:
                good.append(m)
        
        if len(good) > 10:
            src_pts = np.float32([kp1[m.queryIdx].pt for m in good]).reshape(-1, 1, 2)
            dst_pts = np.float32([kp2[m.trainIdx].pt for m in good]).reshape(-1, 1, 2)
            
            H, mask = cv2.findHomography(src_pts, dst_pts, cv2.RANSAC, 5.0)
            return H
        
        return None

# 使用示例
detector = FeatureDetector()
img1 = cv2.imread('image1.jpg', 0)
img2 = cv2.imread('image2.jpg', 0)

result, num_matches = detector.match_features(img1, img2)
print(f"匹配點(diǎn)數(shù)量: {num_matches}")

cv2.imshow('Matches', result)
cv2.waitKey(0)
cv2.destroyAllWindows()

ERROR: Could not find a version that satisfies the requirement opencv-python

# 更新pip
python -m pip install --upgrade pip

# 使用國內(nèi)鏡像
pip install opencv-python -i https://pypi.tuna.tsinghua.edu.cn/simple

# 如果還是失敗，嘗試安裝特定版本
pip install opencv-python==4.5.5.64

ImportError: libGL.so.1: cannot open shared object file

# Ubuntu/Debian
sudo apt-get install libgl1-mesa-glx
sudo apt-get install libglib2.0-0

# 或安裝headless版本
pip install opencv-python-headless

import cv2
import os

# 檢查文件是否存在
image_path = "image.jpg"
if not os.path.exists(image_path):
    print(f"文件不存在: {image_path}")
else:
    image = cv2.imread(image_path)
    if image is None:
        print("文件存在但無法讀取，可能是格式問題")
    else:
        print("讀取成功")

# 處理中文路徑問題
def cv_imread(file_path):
    """支持中文路徑的圖像讀取"""
    cv_img = cv2.imdecode(np.fromfile(file_path, dtype=np.uint8), -1)
    return cv_img

import cv2

# 分塊處理大圖像
def process_large_image(image_path, block_size=1000):
    """分塊處理大圖像"""
    image = cv2.imread(image_path)
    h, w = image.shape[:2]
    
    results = []
    for y in range(0, h, block_size):
        for x in range(0, w, block_size):
            # 提取圖像塊
            block = image[y:y+block_size, x:x+block_size]
            # 處理圖像塊
            processed = process_block(block)
            results.append(processed)
    
    return results

def process_block(block):
    """處理單個(gè)圖像塊"""
    # 這里添加具體的處理邏輯
    return cv2.GaussianBlur(block, (5, 5), 0)

# 1. 使用有意義的變量名
image_height, image_width = image.shape[:2]  # ? 好
h, w = image.shape[:2]  # ? 不夠清晰

# 2. 添加文檔字符串
def detect_faces(image, scale_factor=1.1, min_neighbors=5):
    """
    檢測圖像中的人臉
    
    Args:
        image: 輸入圖像（BGR格式）
        scale_factor: 圖像縮放因子
        min_neighbors: 候選框鄰居數(shù)量
    
    Returns:
        faces: 人臉邊界框列表 [(x, y, w, h), ...]
    """
    pass

# 3. 使用類型注解
def resize_image(image: np.ndarray, scale: float) -> np.ndarray:
    h, w = image.shape[:2]
    new_size = (int(w * scale), int(h * scale))
    return cv2.resize(image, new_size)

# 4. 異常處理
try:
    image = cv2.imread('image.jpg')
    if image is None:
        raise ValueError("無法讀取圖像")
    # 處理圖像...
except Exception as e:
    print(f"錯(cuò)誤: {e}")