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概述

字节 Seedream 系列图像生成模型，支持文生图、图生图、多图融合、批量生成和流式输出。

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支持的模型

模型特点
seedream-4.5最新版本，功能最全，支持高分辨率、图生图、多图融合、批量生成、流式输出
seedream-4.0稳定版本，支持高分辨率、图生图、多图融合
seedream-3.0-t2i基础文生图，仅支持文本生成图像

官方API文档

查看字节官方API参数说明

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请求参数

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基础参数

参数类型必填说明
modelstring是模型名称：seedream-3.0-t2i、seedream-4.0、seedream-4.5
promptstring是图像生成提示词，最多 2000 tokens
sizestring否输出图像尺寸，支持简化格式或像素格式（见下方说明）
ninteger否生成图片数量，范围 1-15，默认 1
watermarkboolean否是否添加水印，默认 true
prompt_prioritystring否提示词优化策略：standard（标准模式，质量更高，处理时间更长）

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尺寸参数 (size)

支持两种格式：
格式说明示例
简化格式模型自动确定最佳尺寸2K、4K
像素格式显式指定宽×高2048x2048、2560x1440、4096x4096
使用简化格式时，可在 prompt 中描述宽高比/形状/用途，模型会自动选择最佳分辨率

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支持的分辨率

以下是 Seedream 4.0/4.5 常用分辨率对照表：
宽高比像素尺寸 (宽×高)
1:12048×2048
4:32304×1728
3:41728×2304
16:92560×1440
9:161440×2560

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图片限制

限制项说明
宽高比范围[1/16, 16]
最小宽高大于 14 像素
最大总像素不超过 6000×6000
单张图片大小最大 10MB
支持格式.jpeg, .jpg, .png, .webp, .bmp, .tiff, .gif
最大参考图数量14 张
参考图+生成图总数≤ 15 张

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图生图参数

参数类型必填说明
image / image_urlsstring/array否参考图像URL，单图为字符串，多图为数组（最多14张）
sequential_image_generationstring否图像生成模式：disabled（单图输出）、auto（批量生成）
sequential_image_generation_optionsobject否批量生成选项，需配合 sequential_image_generation: "auto"
sequential_image_generation_options.max_imagesinteger否批量生成的最大图片数量

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流式输出参数

参数类型必填说明
streamboolean否是否启用流式输出，默认 false

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回调参数

参数类型必填说明
callback_urlstring否任务完成后的 HTTPS 回调地址（仅 HTTPS，最长 2048 字符，超时 10s，最多重试 3 次）

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文生图用例

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seedream-3.0-t2i

基础文生图，无需复杂配置： 
curl https://api.aigc.it/v1/images/generations \
  -H "Content-Type: application/json" \
  -H "Authorization: Bearer <YOUR_TOKEN>" \
  -d '{
    "model": "seedream-3.0-t2i",
    "prompt": "a cat"
  }'

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seedream-4.0 / seedream-4.5

支持高分辨率和水印控制： 
curl https://api.aigc.it/v1/images/generations \
  -H "Content-Type: application/json" \
  -H "Authorization: Bearer <YOUR_TOKEN>" \
  -d '{
    "model": "seedream-4.5",
    "prompt": "a cat",
    "size": "2K",
    "watermark": false
  }'
返回示例： 
{
  "model": "seedream-4-5-251128",
  "created": 1757323224,
  "data": [
    {
      "url": "https://...",
      "size": "1760x2368"
    }
  ],
  "usage": {
    "generated_images": 1,
    "output_tokens": 16280,
    "total_tokens": 16280
  }
}

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图生图用例

基于单张参考图进行重绘或变体生成。 核心参数：
  • image：单张图片URL（字符串）
  • sequential_image_generation：设为 "disabled" 表示单图输出
curl https://api.aigc.it/v1/images/generations \
  -H "Content-Type: application/json" \
  -H "Authorization: Bearer <YOUR_TOKEN>" \
  -d '{
    "model": "seedream-4.5",
    "prompt": "Keep the model pose... Change clothing to transparent water...",
    "image": "https://ark-doc.tos-ap-southeast-1.bytepluses.com/doc_image/seedream4_5_imageToimage.png",
    "size": "2K",
    "watermark": false
  }'
返回示例： 
{
  "model": "seedream-4-5-251128",
  "created": 1757323224,
  "data": [
    {
      "url": "https://...",
      "size": "1760x2368"
    }
  ],
  "usage": {
    "generated_images": 1,
    "output_tokens": 16280,
    "total_tokens": 16280
  }
}

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多图融合用例

多张参考图生成单张结果（如：人物+服装=换装效果）。 核心参数：
  • image：多张图片URL（数组）
  • sequential_image_generation：设为 "disabled" 表示融合输出单图
curl https://api.aigc.it/v1/images/generations \
  -H "Content-Type: application/json" \
  -H "Authorization: Bearer <YOUR_TOKEN>" \
  -d '{
    "model": "seedream-4.5",
    "prompt": "Replace the clothing in image 1 with the outfit from image 2.",
    "image": [
      "https://ark-doc.tos-ap-southeast-1.bytepluses.com/doc_image/seedream4_5_imageToimage.png",
      "https://ark-doc.tos-ap-southeast-1.bytepluses.com/doc_image/seedream4_5_clothing.png"
    ],
    "sequential_image_generation": "disabled",
    "size": "2K",
    "watermark": false
  }'
返回示例： 
{
  "model": "seedream-4-5-251128",
  "created": 1757323224,
  "data": [
    {
      "url": "https://...",
      "size": "1760x2368"
    }
  ],
  "usage": {
    "generated_images": 1,
    "output_tokens": 16280,
    "total_tokens": 16280
  }
}

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批量生成用例

一次生成多张图片，适合需要多个变体的场景。 核心参数：
  • sequential_image_generation：设为 "auto" 启用批量生成
  • sequential_image_generation_options.max_images：指定生成数量
curl https://api.aigc.it/v1/images/generations \
  -H "Content-Type: application/json" \
  -H "Authorization: Bearer <YOUR_TOKEN>" \
  -d '{
    "model": "seedream-4.5",
    "prompt": "Generate 3 images of a girl riding a roller coaster...",
    "image": [
      "https://ark-doc.tos-ap-southeast-1.bytepluses.com/doc_image/seedream4_5_imageToimage.png"
    ],
    "sequential_image_generation": "auto",
    "sequential_image_generation_options": {
      "max_images": 3
    },
    "size": "2K",
    "watermark": false
  }'
返回示例： 
{
  "model": "seedream-4-5-251128",
  "created": 1757388756,
  "data": [
    { "url": "https://...", "size": "2720x1536" },
    { "url": "https://...", "size": "2720x1536" },
    { "url": "https://...", "size": "2720x1536" }
  ],
  "usage": {
    "generated_images": 3,
    "output_tokens": 48960,
    "total_tokens": 48960
  }
}

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流式输出用例

使用 Server-Sent Events (SSE) 实时返回生成进度和结果。 核心参数：
  • stream：设为 true 启用流式输出
  • 配合 sequential_image_generation: "auto" 使用效果最佳
curl https://api.aigc.it/v1/images/generations \
  -H "Content-Type: application/json" \
  -H "Authorization: Bearer <YOUR_TOKEN>" \
  -d '{
    "model": "seedream-4.5",
    "prompt": "Generate four images of different poses...",
    "image": "https://ark-doc.tos-ap-southeast-1.bytepluses.com/doc_image/seedream4_5_imageToimage.png",
    "sequential_image_generation": "auto",
    "sequential_image_generation_options": {
      "max_images": 4
    },
    "size": "2K",
    "stream": true,
    "watermark": false
  }'
流式返回示例： 
event: image_generation.partial_succeeded
data: {
  "type": "image_generation.partial_succeeded",
  "model": "seedream-4-5-251128",
  "created": 1757396757,
  "image_index": 0,
  "url": "https://...",
  "size": "2496x1664"
}

event: image_generation.partial_succeeded
data: {
  "type": "image_generation.partial_succeeded",
  "model": "seedream-4-5-251128",
  "created": 1757396785,
  "image_index": 1,
  "url": "https://...",
  "size": "2496x1664"
}

event: image_generation.completed
data: {
  "type": "image_generation.completed",
  "model": "seedream-4-5-251128",
  "created": 1757396825,
  "usage": {
    "generated_images": 2,
    "output_tokens": 48672,
    "total_tokens": 48672
  }
}

data: [DONE]