How to Auto-Generate Tech Blog Cover Images with an Image‑Generation AI

This article is the Day 1 entry of the KINTO Technologies Advent Calendar 2025:santa::christmas_tree:

I'm okapi from the Mobile team in the QA Group.

When creating images with AI, have you ever experienced telling the AI exactly what you want through prompts, only to have your intent misunderstood, forcing you to redo it multiple times?

This time, I've created a prompt that can generate tech blog cover images in a single generation!

This approach can be applied to other image creation tasks as well. Please give it a try!

How to Use

AI Image‑generation to Use

Microsoft Copilot
*Basically, any generative AI tool that supports image generation will work (e.g., ChatGPT, DALL-E, Midjourney, etc.)

Prompt Modification Points

There are only 4 points to modify in the prompt!

Actual Prompt Used

Please create a cover image for a tech blog.
Please use the same format as the image used in the previous tech blog I'm attaching.

■Purpose
I want to create a cover image for the following blog article.

■Display Title
(Paste article title here)

■Notes
・Please ensure there are no unnatural Japanese expressions.
・Please keep the image style and layout the same as before.
・The title should be placed in the center or a prominent position

■Style
(Choose one from the following 3)
・Tech feel (technical atmosphere)
・AI and machine learning style (collaboration with generative AI)
・Motion graphics style (even as a still image)

■Tech Blog Content
(Paste article overview here)

Previous Cover Image Attached

Images Actually Created for This Article

For this article, I created images in the 3 patterns mentioned above.

Style	Generated Image
Tech feel (technical atmosphere)
AI and machine learning style (collaboration with generative AI)
Motion graphics style (even as a still image)

Key Points of Prompt Design Explained

Not Complete (Still Not Perfect)

This template can mass-produce images while maintaining reproducibility just by replacing 4 points: title, style, overview, and reference image.

Actually, There Are 2 Issues

Although I could generate images in one shot, upon closer inspection, the following 2 problems were found.

Issue 1: Japanese Typos

Despite stating "avoid unnatural Japanese expressions" in the prompt, typos occurred.

Tech feel (technical atmosphere):

• It's written as "自動化化", where "化" is repeated
• The display of "開発" is distorted

AI and machine learning style (collaboration with generative AI):

• It's written as "機械学", where "習" is missing

Issue 2: Logo Modification

I wanted the reference image's logo to be reproduced, but the generative AI subtly modified the logo.

At first glance they look the same, but upon closer inspection, you can see that the design has subtly changed.

From a copyright and brand guidelines perspective, we want to avoid logo modifications.

Tried to Improve

Response to Issue 1: Japanese Typos

I adjusted the prompt notes so the Japanese wouldn’t sound awkward, and tried out a few versions.

Response to Issue 2: Logo Modification

To accurately reproduce the logo, I tried the following prompt adjustments.
Additional prompt: I want the logo below to be exactly the same, so please attach the logo and use the attached file(rogo.png).
As a result, a logo close to the original was created, but the angle and thickness were slightly different.

Conclusion

While image creation itself can be done in one shot, there were the following 2 issues:

1. Japanese kanji expressions - Difficult to control perfectly with prompts alone
2. Accurate logo reproduction - AI automatically modifies it

Through this trial and error process, I think we can understand the characteristics and limitations of generative AI and find more effective ways to use it.

Practical operational method:

• Leave layout, atmosphere, and background generation to the image‑generation AI (AI's strong point)
• Add logos later with image editing tools (humans control accurately)

With this combination, I found that we can leverage the strengths of image-generation AI while ensuring a certain level of quality.

This tech blog cover image was created using the above operation with the logo manually pasted.

If anyone has a prompt that can accurately reproduce kanji and logos in AI-generated images, please let me know!

I’ll write more articles when I find new and interesting AI applications, along with challenges and solutions.