模型调优简介

图像

计算公式：图像 Token = h_bar * w_bar / token_pixels + 2

• h_bar、w_bar：缩放后的图像长宽，模型在处理图像前会进行预处理，会将图像缩小至特定像素上限内，像素上限与max_pixels和vl_high_resolution_images参数的取值有关。

• token_pixels：每视觉Token对应的像素值，不同模型情况不同：

  • qwen3.7系列、qwen3.6系列、qwen3.5系列、Qwen3-VL、qwen-vl-max、qwen-vl-plus：每个Token对应 32x32像素

  • QVQ及其他Qwen2.5-VL模型：每个Token对应28x28像素

以下代码演示了模型内部对图像的大致缩放逻辑，可用于估算一张图像的Token，实际计费请以API响应为准。

import math
from PIL import Image  # pip install Pillow

def smart_size(image_path, max_pixels, vl_high_resolution_images):
    """根据模型参数，计算图像缩放后的尺寸，用于估算图像 Token。"""
    image = Image.open(image_path)
    height, width = image.height, image.width

    # Qwen3.6、Qwen3.5、Qwen3-VL 等模型的缩放因子为 32；其他模型为 28
    factor = 32
    h_bar = round(height / factor) * factor
    w_bar = round(width / factor) * factor

    # Token 下限：4 个 Token
    min_pixels = 4 * factor * factor

    # vl_high_resolution_images=True 时，Token 上限固定为 16384，忽略 max_pixels
    if vl_high_resolution_images:
        max_pixels = 16384 * factor * factor

    # 将总像素数约束在 [min_pixels, max_pixels] 范围内
    if h_bar * w_bar > max_pixels:
        beta = math.sqrt((height * width) / max_pixels)
        h_bar = math.floor(height / beta / factor) * factor
        w_bar = math.floor(width / beta / factor) * factor
    elif h_bar * w_bar < min_pixels:
        beta = math.sqrt(min_pixels / (height * width))
        h_bar = math.ceil(height * beta / factor) * factor
        w_bar = math.ceil(width * beta / factor) * factor

    return h_bar, w_bar

if __name__ == "__main__":
    # 注意：max_pixels 和 vl_high_resolution_images 的值需要与调用模型时传入的参数保持一致
    h_bar, w_bar = smart_size("xxx/test.jpg", max_pixels=2560 * 32 * 32, vl_high_resolution_images=False)
    print(f"缩放后的图像尺寸：高度 {h_bar}，宽度 {w_bar}")

    # 每张图像额外包含 <vision_bos> 和 <vision_eos> 各 1 个 Token
    token = int(h_bar * w_bar / (32 * 32)) + 2
    print(f"图像的 Token 数：{token}")

视频

• 视频文件：

  模型处理视频文件时，会先进行抽帧，然后计算所有视频帧的总 Token 数。由于该计算过程较为复杂，可使用以下代码，通过传入视频路径来估算视频消耗的总 Token 数：

  # 使用前安装：pip install opencv-python
  import math
  import os
  import logging
  import cv2
  
  logger = logging.getLogger(__name__)
  
  FRAME_FACTOR = 2
  
  # Qwen3.6、Qwen3.5、Qwen3-VL、qwen-vl-max-0813、qwen-vl-plus-0815、qwen-vl-plus-0710等模型，图像缩放因子为32
  IMAGE_FACTOR = 32
  
  #  其他模型，图像缩放因子为28
  # IMAGE_FACTOR = 28
  
  # 视频帧的最大长宽比
  MAX_RATIO = 200
  # 视频帧的像素下限
  VIDEO_MIN_PIXELS = 4 * 32 * 32
  # 视频帧的像素上限，使用Qwen3-VL-Plus模型，VIDEO_MAX_PIXELS为640 * 32 * 32，其他模型为768 * 32 * 32
  VIDEO_MAX_PIXELS = 640 * 32 * 32
  
  # 用户未传入FPS参数，则fps使用默认值
  FPS = 2.0
  # 最少抽取帧数
  FPS_MIN_FRAMES = 4
  # 最大抽取帧数（根据模型选择设置值）
  FPS_MAX_FRAMES = 2000
  
  # 视频输入的最大像素值，使用Qwen3-VL-Plus模型，请将VIDEO_TOTAL_PIXELS设置为131072 * 32 * 32，其他模型设置为65536 * 32 * 32
  VIDEO_TOTAL_PIXELS = int(float(os.environ.get('VIDEO_MAX_PIXELS', 131072 * 32 * 32)))
  
  def round_by_factor(number: int, factor: int) -> int:
      """返回与”number“最接近的整数，该整数可被”factor“整除。"""
      return round(number / factor) * factor
  
  def ceil_by_factor(number: int, factor: int) -> int:
      """返回大于或等于“number”且可被“factor”整除的最小整数。"""
      return math.ceil(number / factor) * factor
  
  def floor_by_factor(number: int, factor: int) -> int:
      """返回小于或等于“number”且可被“factor”整除的最大整数。"""
      return math.floor(number / factor) * factor
  
  def extract_vision_info(conversations):
      vision_infos = []
      if isinstance(conversations[0], dict):
          conversations = [conversations]
      for conversation in conversations:
          for message in conversation:
              if isinstance(message["content"], list):
                  for ele in message["content"]:
                      if (
                          "image" in ele
                          or "image_url" in ele
                          or "video" in ele
                          or ele.get("type","") in ("image", "image_url", "video")
                      ):
                          vision_infos.append(ele)
      return vision_infos
  
  def smart_nframes(ele,total_frames,video_fps):
      """用于计算抽取的视频帧数。
  
      Args:
          ele (dict): 包含视频配置的字典格式
              - fps: fps用于控制提取模型输入帧的数量。
          total_frames (int): 视频的原始总帧数。
          video_fps (int | float): 视频的原始帧率
  
      Raises:
          nframes应该在[FRAME_FACTOR，total_frames]间隔内，否则会报错
  
      Returns:
          用于模型输入的视频帧数。
      """
      assert not ("fps" in ele and "nframes" in ele), "Only accept either `fps` or `nframes`"
      fps = ele.get("fps", FPS)
      min_frames = ceil_by_factor(ele.get("min_frames", FPS_MIN_FRAMES), FRAME_FACTOR)
      max_frames = floor_by_factor(ele.get("max_frames", min(FPS_MAX_FRAMES, total_frames)), FRAME_FACTOR)
      duration = total_frames / video_fps if video_fps != 0 else 0
      if duration-int(duration)>(1/fps):
          total_frames = math.ceil(duration * video_fps)
      else:
          total_frames = math.ceil(int(duration)*video_fps)
      nframes = total_frames / video_fps * fps
      if nframes > total_frames:
          logger.warning(f"smart_nframes: nframes[{nframes}] > total_frames[{total_frames}]")
      nframes = int(min(min(max(nframes, min_frames), max_frames), total_frames))
      if not (FRAME_FACTOR <= nframes and nframes <= total_frames):
          raise ValueError(f"nframes should in interval [{FRAME_FACTOR}, {total_frames}], but got {nframes}.")
  
      return nframes
  
  def get_video(video_path):
      # 获取视频信息
      cap = cv2.VideoCapture(video_path)
  
      frame_width = int(cap.get(cv2.CAP_PROP_FRAME_WIDTH))
      # 获取视频高度
      frame_height = int(cap.get(cv2.CAP_PROP_FRAME_HEIGHT))
      total_frames = int(cap.get(cv2.CAP_PROP_FRAME_COUNT))
  
      video_fps = cap.get(cv2.CAP_PROP_FPS)
      return frame_height, frame_width, total_frames, video_fps
  
  def smart_resize(ele, path, factor=IMAGE_FACTOR):
      # 获取原视频的宽和高
      height, width, total_frames, video_fps = get_video(path)
      # 视频帧的Token下限
      min_pixels = VIDEO_MIN_PIXELS
      total_pixels = VIDEO_TOTAL_PIXELS
      # 抽取的视频帧数
      nframes = smart_nframes(ele, total_frames, video_fps)
      max_pixels = max(min(VIDEO_MAX_PIXELS, total_pixels / nframes * FRAME_FACTOR),int(min_pixels * 1.05))
  
      # 视频的长宽比不应超过200:1或1:200
      if max(height, width) / min(height, width) > MAX_RATIO:
          raise ValueError(
              f"absolute aspect ratio must be smaller than {MAX_RATIO}, got {max(height, width) / min(height, width)}"
          )
  
      h_bar = max(factor, round_by_factor(height, factor))
      w_bar = max(factor, round_by_factor(width, factor))
      if h_bar * w_bar > max_pixels:
          beta = math.sqrt((height * width) / max_pixels)
          h_bar = floor_by_factor(height / beta, factor)
          w_bar = floor_by_factor(width / beta, factor)
      elif h_bar * w_bar < min_pixels:
          beta = math.sqrt(min_pixels / (height * width))
          h_bar = ceil_by_factor(height * beta, factor)
          w_bar = ceil_by_factor(width * beta, factor)
      return h_bar, w_bar
  
  def token_calculate(video_path, fps):
      # 传入视频路径和fps抽帧参数
      messages = [{"content": [{"video": video_path, "fps": fps}]}]
      vision_infos = extract_vision_info(messages)[0]
  
      resized_height, resized_width = smart_resize(vision_infos, video_path)
  
      height, width, total_frames, video_fps = get_video(video_path)
      num_frames = smart_nframes(vision_infos, total_frames, video_fps)
      print(f"原视频尺寸：{height}*{width}， 输入模型的尺寸：{resized_height}*{resized_width}，视频总帧数:{total_frames}，fps等于{fps}时，抽取的总帧数：{num_frames}", end="，")
      video_token = int(math.ceil(num_frames / 2) * resized_height / 32 * resized_width / 32)
      video_token += 2   # 系统会自动添加<|vision_bos|>和<|vision_eos|>视觉标记（各计1个Token）
      return video_token
  
  video_token = token_calculate("xxx/test.mp4", 1)
  print("视频tokens:", video_token)

• 图像列表：

  当以图像列表形式传入视频时，表示已预先完成视频抽帧，可使用以下代码，通过传入图像的路径和数量来计算传入图像列表时消耗的Token数：

  # 使用前安装：pip install Pillow
  import math
  import os
  import logging
  from typing import Tuple
  from PIL import Image
  
  logger = logging.getLogger(__name__)
  
  # ==================== 常量定义 ====================
  FRAME_FACTOR = 2
  # Qwen3-VL、qwen-vl-max-0813、qwen-vl-plus-0815、qwen-vl-plus-0710模型，缩放因子为32
  IMAGE_FACTOR = 32
  
  #  其他模型，缩放因子为28
  # IMAGE_FACTOR = 28
  
  # Token计算相关常量
  TOKEN_DIVISOR = 32  # token计算时的除数
  VISION_SPECIAL_TOKENS = 2  # <|vision_bos|>和<|vision_eos|>标记
  
  # 视频帧的最大长宽比
  MAX_RATIO = 200
  # 视频帧的像素下限
  VIDEO_MIN_PIXELS = 4 * 32 * 32
  # 视频帧的像素上限，使用Qwen3-VL-Plus模型，VIDEO_MAX_PIXELS为640 * 32 * 32，其他模型为768 * 32 * 32
  VIDEO_MAX_PIXELS = 640 * 32 * 32
  
  # 视频输入的最大像素值，使用Qwen3-VL-Plus模型，请将VIDEO_TOTAL_PIXELS设置为131072 * 32 * 32，其他模型设置为65536 * 32 * 32
  VIDEO_TOTAL_PIXELS = int(float(os.environ.get('VIDEO_MAX_PIXELS', 131072 * 32 * 32)))
  
  def round_by_factor(number: int, factor: int) -> int:
      """返回与”number“最接近的整数，该整数可被”factor“整除。"""
      return round(number / factor) * factor
  
  def ceil_by_factor(number: int, factor: int) -> int:
      """返回大于或等于“number”且可被“factor”整除的最小整数。"""
      return math.ceil(number / factor) * factor
  
  def floor_by_factor(number: int, factor: int) -> int:
      """返回小于或等于“number”且可被“factor”整除的最大整数。"""
      return math.floor(number / factor) * factor
  
  def get_image_size(image_path: str) -> Tuple[int, int]:
      if not os.path.exists(image_path):
          raise FileNotFoundError(f"图像文件不存在: {image_path}")
  
      try:
          image = Image.open(image_path)
          height = image.height
          width = image.width
          image.close()  # 及时关闭文件
          return height, width
      except Exception as e:
          raise ValueError(f"无法读取图像文件 {image_path}: {str(e)}")
  
  def smart_resize(height: int, width: int, nframes: int, factor: int = IMAGE_FACTOR) -> Tuple[int, int]:
      """
      计算图像缩放后的尺寸
  
      Args:
          height: 原始图像高度
          width: 原始图像宽度
          nframes: 视频帧数
          factor: 缩放因子，默认为IMAGE_FACTOR
  
      Returns:
          (resized_height, resized_width) 缩放后的高度和宽度
  
      Raises:
          ValueError: 长宽比超过限制
      """
      # 视频帧的Token下限
      min_pixels = VIDEO_MIN_PIXELS
      total_pixels = VIDEO_TOTAL_PIXELS
      # 抽取的视频帧数
      max_pixels = max(min(VIDEO_MAX_PIXELS, total_pixels / nframes * FRAME_FACTOR), int(min_pixels * 1.05))
  
      # 视频的长宽比不应超过200:1或1:200
      aspect_ratio = max(height, width) / min(height, width)
      if aspect_ratio > MAX_RATIO:
          raise ValueError(
              f"图像长宽比必须小于 {MAX_RATIO}:1，当前为 {aspect_ratio:.2f}:1"
          )
  
      h_bar = max(factor, round_by_factor(height, factor))
      w_bar = max(factor, round_by_factor(width, factor))
      if h_bar * w_bar > max_pixels:
          beta = math.sqrt((height * width) / max_pixels)
          h_bar = floor_by_factor(height / beta, factor)
          w_bar = floor_by_factor(width / beta, factor)
      elif h_bar * w_bar < min_pixels:
          beta = math.sqrt(min_pixels / (height * width))
          h_bar = ceil_by_factor(height * beta, factor)
          w_bar = ceil_by_factor(width * beta, factor)
      return h_bar, w_bar
  
  def calculate_video_tokens(image_path: str, nframes: int = 1, factor: int = IMAGE_FACTOR, verbose: bool = True) -> int:
      """
  
      Args:
          image_path: 视频帧文件路径
          nframes: 视频帧数，
          factor: 缩放因子，默认为IMAGE_FACTOR
          verbose: 是否打印详细信息
  
      Returns:
          所消耗的token数量
  
      Raises:
          FileNotFoundError: 文件不存在
          ValueError: 文件格式无效或长宽比超限
      """
      # 获取原始图像尺寸（只读取一次）
      height, width = get_image_size(image_path)
  
      # 计算缩放后的尺寸
      resized_height, resized_width = smart_resize(height, width, nframes, factor)
  
      # 计算token数量
      # 公式：⌈帧数/2⌉ × (高度/TOKEN_DIVISOR) × (宽度/TOKEN_DIVISOR) + VISION_SPECIAL_TOKENS
      video_token = int(
          math.ceil(nframes / 2) *
          (resized_height / TOKEN_DIVISOR) *
          (resized_width / TOKEN_DIVISOR)
      )
      # 添加视觉标记token（<|vision_bos|>和<|vision_eos|>）
      video_token += VISION_SPECIAL_TOKENS
  
      if verbose:
          print(f"原视频帧尺寸：{height}×{width}，输入模型的尺寸：{resized_height}×{resized_width}，", end="")
  
      return video_token
  
  if __name__ == "__main__":
      try:
          video_token = calculate_video_tokens("xxx/test.jpg", nframes=30)
          print(f"视频tokens: {video_token}\n")
      except Exception as e:
          print(f"错误: {str(e)}\n")