【Opencv中的Jpeg有损压缩】

import cv2
import numpy as np

def compress_and_decompress_image(image_path, quality=75):
    # 读取图像
    image = cv2.imread(image_path)
    if image is None:
        print("图像读取失败！")
        return None

    # 使用 imencode 函数进行 JPEG 编码
    success, encoded_image = cv2.imencode('.jpg', image, [int(cv2.IMWRITE_JPEG_QUALITY), quality])

    if not success:
        print("图像编码失败！")
        return None

    print(f"图像已成功编码为 JPEG 格式，压缩后的数据大小为: {len(encoded_image)} 字节")

    # 使用 imdecode 函数将编码后的数据解码为图像
    decoded_image = cv2.imdecode(encoded_image, cv2.IMREAD_COLOR)

    if decoded_image is None:
        print("图像解码失败！")
        return None

    print("图像已成功解码为正常格式。")

    return decoded_image

# 示例用法
image_path = 'test3.png'  # 替换为你的图像路径
decompressed_image = compress_and_decompress_image(image_path, quality=55)


# 显示原始图像和解码后的图像（仅作为示例）
if decompressed_image is not None:
    original_image = cv2.imread(image_path)  # 重新读取原始图像以进行比较
    cv2.imshow('Original Image', original_image)
    cv2.imshow('Decompressed Image', decompressed_image)
    cv2.waitKey(0)
    cv2.destroyAllWindows()


# # 如果需要，可以将压缩后的数据写入到文件（仅作为示例，实际不需要保存）
# if compressed_data is not None:
#     with open('compressed_image.jpg', 'wb') as f:
#         f.write(compressed_data.tobytes())  # 实际上不需要这一步，仅用于演示