抠图后更新为保存为png格式，处理速度更快

apps/rmbg/service.py

@@ -424,10 +424,10 @@ class RmbgService:
     
     def save_image_to_file(self, image):
         """保存图片到文件并返回URL"""
-        filename = f"rmbg_{uuid.uuid4().hex[:10]}.webp"
+        # 改为保存 PNG，使用标准压缩级别（Pillow 默认 compress_level=6）
+        filename = f"rmbg_{uuid.uuid4().hex[:10]}.png"
         file_path = os.path.join(self.save_dir, filename)
-
-        image.save(file_path, format="WEBP", quality=85, method=6)
+        image.save(file_path, format="PNG")
         image_url = f"{self.download_url}/{filename}"
         return image_url