My JPG image has a white background around it. I don’t want to change the image itself, I just want to make the white background transparent.Here is the code:

import cv2
import numpy as np
from PIL import Image

# 文件路径和文件名
path = "images/"
filename = "demo.jpg"
input_filepath = path + filename
output_filepath = path + "demo_transparent.png"

# 读取彩色图像
img = cv2.imread(input_filepath)

# 转换为灰度图像
gray = cv2.cvtColor(img, cv2.COLOR_BGR2GRAY)

# 定义阈值
thresh = 250

# 阈值化图像
_, binary = cv2.threshold(gray, thresh, 255, cv2.THRESH_BINARY)

# 查找图像中的轮廓
contours, _ = cv2.findContours(binary, cv2.RETR_EXTERNAL, cv2.CHAIN_APPROX_SIMPLE)

# 创建一个全白的掩码
mask = np.ones_like(gray) * 255

# 绘制找到的轮廓，填充内部区域
cv2.drawContours(mask, contours, -1, 0, thickness=cv2.FILLED)

# 反转掩码
mask = cv2.bitwise_not(mask)

# 将原图转换为包含透明通道的图像
rgba = cv2.cvtColor(img, cv2.COLOR_BGR2BGRA)

# 遍历图像像素，将白色背景变为透明
height, width = mask.shape
for y in range(height):
    for x in range(width):
        if mask[y, x] == 255 and np.all(rgba[y, x][:3] == 255):
            rgba[y, x][3] = 0  # 设置Alpha通道为0（透明）

# 将结果保存为PNG图像
result = Image.fromarray(rgba)
result.save(output_filepath)

print(f"Processed image saved at: {output_filepath}")

This code does help me make the white background around the image transparent, but it also changes the color of the image. I would like to ask how to keep the original image? Thanks.

I tried asking ChatGTP to help me out but he is no smarter than a human.