Image Generation: Aspect Ratios, Resolution & Best Practices

Learn how aspect ratios, resolutions, and reference images affect AI image generation in ACE AI Spark. Tips for getting the best results with Nano Banana.

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ACE AI Spark's image generation tool lets you create images directly inside your video projects. This guide covers how aspect ratios, resolutions, and reference images affect your output — and how to get the best results.

📐 Supported Aspect Ratios & Resolutions

When you generate an image, the output dimensions are determined by your project's orientation:

16:9 (Landscape)
1920 × 1080 pixels 9:16 (Portrait)
1080 × 1920 pixels

These dimensions are enforced via the API request, ensuring your generated images match the video project's aspect ratio.

🖼️ Three Ways to Add Images

Each scene in your storyboard supports three image source options:

Upload Your Own

Upload an image from your device. The file is stored in your media library and a signed URL is created for video generation. Tip: Use images that match your project's aspect ratio (e.g., 1920×1080 for 16:9 projects) for best results.

Browse Media Library

Choose from images you've previously uploaded or generated. This is a great way to reuse brand assets, logos, or AI-generated images across multiple scenes or projects.

AI Generate

Describe the image you want and the built-in AI image engine generates it. The output dimensions will match your project's aspect ratio automatically — no reference image is involved, so dimensions are exact.

⚠️ Reference Image Limitation

When you use a reference image (uploaded or from library), the AI image generation API treats the requested dimensions as a hint. The output may match the reference image's native resolution instead of your project's target aspect ratio.

Example: If your project is 16:9 (1920×1080) but your reference image is 1024×1024, the generated image may come out at 1024×1024.

✅ Best Practices

Match your aspect ratio: When uploading reference images, use files that already match your project orientation (landscape for 16:9, portrait for 9:16).
Generate without references for exact dimensions: If you need pixel-perfect 1920×1080 or 1080×1920, use the AI Generate option without a reference image.
Avoid mixing aspect ratios: Using a portrait reference in a landscape project (or vice versa) may produce unexpected crops or black bars in your final video.
Use high-resolution sources: Higher quality reference images produce better AI outputs. Aim for at least 1080p source material.
Check the preview: After generating, review the image in the Images tab to verify dimensions before using it in a video clip.

❓ FAQ

Why is my generated image not 1920×1080?

If you used a reference image, the AI may have matched that image's dimensions instead. Try generating without a reference, or use a reference image that's already 1920×1080.

Can I resize images after generation?

Currently, images are used at their generated size. For best results, ensure correct dimensions at generation time.

What model powers image generation?

Images are generated by ACE AI Spark's built-in AI image engine, tuned for fast, creative image generation.