图生图(Image-to-Image)技巧
学习如何使用 AI 对已有图片进行转换、编辑与增强。这些技巧可以在保持关键元素的同时进行修改。
什么是 Image-to-Image?
Image-to-image(I2I)使用一张已有图片作为输入,引导 AI 生成:
- 🎨 风格迁移 — 给图片应用新的风格
- ✏️ 编辑 — 修改局部元素
- 🔄 变换 — 改变场景或上下文
- 📐 参考 — 用图片引导新的生成
I2I 的关键模型
| Model | Best For | Credits |
|---|---|---|
| Flux Kontext Pro | 精准编辑、修改 | 120 |
| Flux Kontext Max | 复杂变换 | 120 |
| Flux 2 Flex | 风格变化 | 20 |
| SDXL | 艺术风格迁移 | 40 |
技巧 1:替换背景(Background Replacement)
目标
保留主体,替换背景。
工作流
Prompt Template
[Upload] → [BG Remover] → [Flux Kontext] ↑ [Text: New Background]
Prompt 模板
Prompt Template
Place the subject on [new background description], maintain original subject exactly, [lighting that matches new scene], seamless integration
示例
Original: 白底产品图
Prompt: "Place on rustic wooden table, cozy kitchen background, warm morning light, lifestyle photography"
Result: 同一产品出现在生活方式场景中
技巧 2:风格迁移(Style Transfer)
目标
保持内容不变,应用艺术风格。
工作流
Prompt Template
[Upload (Content)] → [Image Node] ↑ [Text: Style Description]
风格 Prompt 模板
Prompt Template
Transform this image into [style] style, maintain the composition and subjects, [style-specific keywords], artistic interpretation
风格示例
Watercolor:
Transform into watercolor painting style,
soft brushstrokes, flowing colors,
artistic and painterly,
maintain composition
Anime/Illustration:
Transform into anime illustration style,
clean lines, vibrant colors,
Japanese animation aesthetic,
maintain character likeness
Vintage:
Transform into vintage photograph style,
faded colors, film grain,
1970s aesthetic, warm tones,
nostalgic feeling
技巧 3:对象编辑(Object Editing)
目标
只改图片里的特定元素。
使用 Flux Kontext
Prompt Template
[Upload] → [Flux Kontext Pro] ↑ [Text: Edit Instructions]
编辑 Prompt 模板
Prompt Template
Change [specific element] to [new element], keep everything else exactly the same, maintain lighting and style
示例
改颜色:
Change the red car to blue,
keep everything else exactly the same
替换物体:
Replace the coffee cup with a wine glass,
maintain the same position and lighting
添加元素:
Add a small plant on the desk,
keep everything else unchanged
技巧 4:扩展场景(Scene Extension)
目标
把画面往边界之外延展(outpainting)。
工作流
Prompt Template
[Upload] → [Image Node (with outpainting)]
Prompt 模板
Prompt Template
Extend the scene [direction], maintain consistent style and lighting, seamless continuation of the original, [describe what should appear in extension]
技巧 5:主体一致性(Subject Consistency)
目标
生成“同一个主体”的新图片。
工作流
Prompt Template
[Upload (Reference)] → [Image Node] ↑ [Text: New Scene]
Prompt 模板
Prompt Template
Same [subject description] as in the reference, now [new scene/action], maintain exact appearance, [style and lighting]
最佳实践
- 用清晰、正面的参考图
- 在 prompt 里也描述主体
- 风格尽量与参考一致
- 用更擅长一致性的模型(Flux Kontext)
技巧 6:照片增强(Photo Enhancement)
目标
提升照片质量或修复问题。
常见增强方式
改善光线:
Enhance the lighting in this photo,
add soft fill light to shadows,
maintain natural look,
professional photo quality
色彩校正:
Correct the color balance,
warmer tones,
more vibrant but natural colors,
professional color grade
质量增强:
Enhance photo quality,
sharpen details,
reduce noise,
professional photography standard
Best Practices
源图质量
| Good | Bad |
|---|---|
| High resolution | Low resolution |
| Clear subject | Blurry |
| Good lighting | Poor exposure |
| Simple composition | Cluttered |
Prompt 具体程度
太模糊:
Make it better
刚刚好:
Change the background to a beach sunset,
keep the person exactly the same,
warm golden lighting on subject
迭代方式
- 从轻微改动开始
- 查看结果
- 调整 prompt
- 必要时再提高改动强度
常见挑战
主体意外变化(Subject Changes Unexpectedly)
原因: prompt 太泛
解决方案: 明确写清楚哪些必须保持不变:
Keep the person's face, clothing, and pose exactly the same,
only change the background
风格不易迁移(Style Doesn't Transfer Well)
原因: 风格描述太泛
解决方案: 使用更具体的风格参照:
In the style of Studio Ghibli animation,
soft colors, detailed backgrounds,
whimsical atmosphere
边缘不自然(Edges Look Unnatural)
原因: 过渡太硬
解决方案: 加入融合/阴影匹配指令:
Seamless integration,
natural edges,
matching lighting and shadows
工作流示例
人像修饰(Portrait Retouching)
Prompt Template
[Upload Portrait] → [Flux Kontext] Prompt: "Subtle skin smoothing, enhance eyes slightly, maintain natural appearance, professional headshot quality"
产品生活方式场景(Product Lifestyle)
Prompt Template
[Upload Product] → [BG Remover] → [Flux Kontext] Prompt: "Place on marble kitchen counter, morning sunlight, modern kitchen background, lifestyle product photography"
艺术化转换(Art Transformation)
Prompt Template
[Upload Photo] → [Image Node (SDXL)] Prompt: "Transform into oil painting, impressionist style, visible brushstrokes, artistic interpretation, gallery quality"
下一步
- Consistent Style — 多张图保持一致
- Tool Nodes — 增强工具
- Flux Models Prompting — Flux 提示词进阶