Best approach for AI-powered content-aware cropping of 7000+ wallpaper images?

問題
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1

I’m building an automated workflow to intelligently crop decorative wallpaper images based on customer wall dimensions (width × height in cm). The catalog has 7000+ images with very different subjects (flowers, leaves, geometric patterns, figures, etc.).

My current approach:

  1. AI Agent with OpenAI Vision analyzes the image and returns crop coordinates as percentages (left, right, focal_y)

  2. A JavaScript node converts percentages to pixels based on image dimensions and wall size

  3. A Python/Pillow node executes the actual crop

The problem is that GPT Vision estimates coordinates visually and is sometimes imprecise — subjects like leaves or flowers end up slightly cut at the edges.

What I already tried:

  • Setting temperature: 0 for determinism :white_check_mark:

  • Detailed prompt with design principles and examples :white_check_mark:

  • focal_y for vertical positioning :white_check_mark:

My question: What would be the best approach to improve precision on a large and varied catalog?

  • Refine the prompt further?

  • Add OpenCV in the Python node to detect precise object boundaries after GPT gives the approximate area?

  • Something else entirely?

n8n version: 2.12.2 (Self Hosted) Running via: Docker OS: Windows Executions process: External task runner (Python)

3

Hey @Alessio_Jeshili, welcome!
I think using this:

would improve your project.

Also, prompts are everything in AI agents, so you have to check your prompts here:

Your project idea is awesome, but 7k images are very concerning. Instead, why don’t you let AI generate the image based on the user requirement? I think that would be cheaper than actually picking an image from that huge catalogue.

4

嗨 Alessio，

我在從不同的角度研究同一個問題時發現了你的帖子 — 使用 Claude（而非 GPT）來返回編輯體育攝影的裁剪座標，然後在 n8n 中透過 ImageMagick 應用裁剪。相同的架構，相同的挫折感：模型進行視覺估計，偶爾會漏掉主體。

如果你自四月以來有時間反覆迭代的話，我有幾個問題：

  1. 你最後是否在 LLM 處理後加入了 OpenCV 來進行邊界精化，還是提示工程已經足夠了？
  2. 你有沒有試過切換到不同的模型（Gemini、Claude）或像 Imagga 這樣的專門裁剪 API？
  3. 你在如何組織座標輸出方面有什麼心得 — 百分比 vs. 像素、邊界框 vs. 焦點？

如果有用的話，我樂意分享我的提示詞迭代。

謝謝
Anders