from PIL import Image
import os


def RGB_compare(base_layer_path, min_size_path, max_size_path, save_path):
    # 加载图像min表示图像1，max表示图像2
    min_size = Image.open(min_size_path)
    min_size = min_size.convert('RGBA')
    max_size = Image.open(max_size_path)
    max_size = max_size.convert('RGBA')
    base_layer = Image.open(base_layer_path)
    base_layer = base_layer.convert('RGBA')
    both = 0  # 记录两幅图都预测出的像素个数
    max_min = 0  # 记录max预测出但是min没有预测出的像素个数
    min_max = 0  # 记录min预测出但是max没有预测出的像素个数
    # 获取图像尺寸
    heigh, width = min_size.size
    for i in range(heigh):
        for j in range(width):
            # 以max作为图像判别标准
            min_r, min_g, min_b, min_a = min_size.getpixel((i, j))
            max_r, max_g, max_b, max_a = max_size.getpixel((i, j))
            # 如果max预测出来了
            if max_r == 128:
                # 如果两张图像都预测出来了便标记为红色
                if min_r == 128:
                    both += 1
                    min_size.putpixel((i, j), (255, 0, 0, 255))
                # 大有小没有便标记为白色
                if min_r == 0:
                    max_min += 1
                    min_size.putpixel((i, j), (255, 255, 255, 255))
            elif max_r == 0:
                # 如果两个都没预测出来,直接设置为背景
                if min_r == 0:
                    min_size.putpixel((i, j), (0, 0, 0, 0))
                # 如果小的有大的没有，设置为绿色
                if min_r == 128:
                    min_max += 1
                    min_size.putpixel((i, j), (0, 255, 0, 255))
    print('both：{}，max_min：{}，min_max：{}'.format(both, max_min, min_max))
    base_layer.paste(min_size, (0, 0), min_size)  # 贴图操作
    base_layer.save(save_path + "/" + "1024_1280.png")  # 图片保存


if __name__ == "__main__":
    base_layer_path = r''
    min_size_path = r''
    max_size_path = r''
    save_path = r''
    RGB_compare(base_layer_path, min_size_path, max_size_path, save_path)

参考：

1.《医学案例统计分析与SAS应用》，冯国双