import cv2
import numpy as np

# 創(chuàng)建一張黑色背景圖
img = np.zeros((500, 500, 3), dtype=np.uint8)

# 定義左上角和右下角坐標
pt1 = (50, 50)      # (x, y)
pt2 = (400, 300)    # (x, y)

# 定義顏色 (OpenCV 是 BGR，所以 (0, 0, 255) 是紅色)
color = (0, 0, 255)

# 定義線寬 (如果是 -1，表示填充)
thickness = 3

# 畫矩形
cv2.rectangle(img, pt1, pt2, color, thickness)

cv2.imshow("OpenCV Rectangle", img)
cv2.waitKey(0)
cv2.destroyAllWindows()

# 畫一個綠色的實心矩形
cv2.rectangle(img, (50, 350), (450, 450), (0, 255, 0), -1)

# 簡單的圓角矩形函數(shù)
def draw_rounded_rectangle(img, pt1, pt2, color, radius, thickness):
    x1, y1 = pt1
    x2, y2 = pt2
    # 畫四條邊
    cv2.line(img, (x1 + radius, y1), (x2 - radius, y1), color, thickness)
    cv2.line(img, (x1 + radius, y2), (x2 - radius, y2), color, thickness)
    cv2.line(img, (x1, y1 + radius), (x1, y2 - radius), color, thickness)
    cv2.line(img, (x2, y1 + radius), (x2, y2 - radius), color, thickness)
    # 畫四個角
    cv2.circle(img, (x1 + radius, y1 + radius), radius, color, thickness)
    cv2.circle(img, (x2 - radius, y1 + radius), radius, color, thickness)
    cv2.circle(img, (x1 + radius, y2 - radius), radius, color, thickness)
    cv2.circle(img, (x2 - radius, y2 - radius), radius, color, thickness)

# 使用
draw_rounded_rectangle(img, (50, 50), (250, 200), (255, 255, 0), 20, 2)

from PIL import Image, ImageDraw

# 創(chuàng)建白色背景圖
img = Image.new('RGB', (500, 500), color='white')
draw = ImageDraw.Draw(img)

# 坐標可以是 [左上角x, 左上角y, 右下角x, 右下角y]
box = [50, 50, 400, 300]

# 畫藍色邊框，寬度為 3
draw.rectangle(box, outline='blue', width=3)

# 畫一個紅色實心矩形
draw.rectangle([50, 350, 450, 450], fill='red')

img.show()

import cv2

img = cv2.imread("test.jpg") # 假設(shè)有一張原圖
x, y, w, h = 100, 100, 200, 300 # 模擬檢測框

# 1. 畫矩形框
cv2.rectangle(img, (x, y), (x+w, y+h), (0, 255, 0), 2)

# 2. 畫文字背景（實心小矩形）
label = "Person"
(text_width, text_height), _ = cv2.getTextSize(label, cv2.FONT_HERSHEY_SIMPLEX, 0.6, 2)
cv2.rectangle(img, (x, y - 25), (x + text_width, y), (0, 255, 0), -1) # 填充

# 3. 寫文字
cv2.putText(img, label, (x, y - 5), cv2.FONT_HERSHEY_SIMPLEX, 0.6, (255, 255, 255), 2)

cv2.imshow("Labeled", img)
cv2.waitKey(0)

def apply_mosaic(img, x, y, w, h, block_size=10):
    """
    對指定區(qū)域 (x, y, w, h) 進行馬賽克處理
    """
    roi = img[y:y+h, x:x+w]
    # 縮小再放大，模擬馬賽克
    roi = cv2.resize(roi, (w // block_size, h // block_size), interpolation=cv2.INTER_LINEAR)
    roi = cv2.resize(roi, (w, h), interpolation=cv2.INTER_NEAREST)
    img[y:y+h, x:x+w] = roi
    return img

# 使用
img = cv2.imread("face.jpg")
img = apply_mosaic(img, 50, 50, 200, 200)
cv2.imshow("Mosaic", img)
cv2.waitKey(0)

import cv2
import numpy as np

img = cv2.imread("test.jpg")
overlay = img.copy()

# 定義區(qū)域
x, y, w, h = 100, 100, 300, 300

# 在覆蓋層上畫一個半透明矩形
# 先畫一個實心矩形
cv2.rectangle(overlay, (x, y), (x+w, y+h), (255, 0, 0), -1)

# 混合原圖和覆蓋層 (alpha=0.3 表示覆蓋層透明度)
cv2.addWeighted(overlay, 0.3, img, 0.7, 0, img)

cv2.imshow("Transparent Overlay", img)
cv2.waitKey(0)