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Use a Nano Banana model to create images

Nano Banana is the common name of a family of AI models from Google that specialize in generating images and modifying existin ones.

Define the image you want

On that screenshot you can see the main controls you have over the image creation.

Aspect ratio

With Nano Banana, you do not define an image size, but instead an aspect ratio.

The aspect ratio is the relationship between the width and the height of the image, and there are a few prefined values that you can use. The most common ones are probably 16:9 and 4:3 for horizontal images, and 4:5 and 9:16 for vertical images.

It's worth noting that Nano Banana can generate both vertical and horizontal images, so you've got a lot of choices here.

Includes text generation

If the image you want to create or modify includes some text, you must set Includes text generation to Yes.

This option causes Nano Banana to pay special attention to properly generates text inside your image. It is very good at it, but it needs to be informed ahead of time that the image includes text.

Instructions to generate the image

This is where you describe the desired content of the image.

Do not start with An image of.... or Create an image of .... Instead, directly describe the content: A wooden bridge over a large river.

Image Alt text is automatically managed

This description will be used as image Alt text later so keep it concise. You can enter additional information about the image, that should not be part of the Alt text in a dedicated separate input field (click on More options to show that field)

Other options

Click the More options button to provide more details about the image you want to create:

  • Custom image generation instructions: As the main description is used for the Alt tag of your image, we want to avoid emcumbering it with extra details. But it is also important to be very specific and explicit about the image you create, so this field content will be passed to the model after the main description but won't be used as part of the Alt tag.

    Examples of custom instructions are: The person should look into the distance or No brand should appear on the character clothing.

  • Modifiers: to help you defines your image characteristics, you'll see 4 selectors below the description with common image specifications. You do not have to use them, they are only here to help and guide as you discover how image generation works

Generate image

Once the above fields are set, click the Submit request button and the image will be generated. The time needed depends on the selected model, image size and quality.

Be aware that generating images is comparatively more expensive than generating text.

The result screen will look like this:

Click the full screen icon in the bottom right corner of the image to view that image full size.

Modify Image

If the image suits your need, you can move on to the next step, Save the image.

But if something's not right, you can either:

  • start again from scratch by clicking Start over
  • ask the AI to modify the image, by clicking on Modify image

Even if you select start over, you can always come back to the image you just generated using the Back to Image button found in the controls.

Explain the modification

Click the Modify button to describe how you want to modify the image:

Use the How should we modify the image? input field to describe how you would like the image to be modified, then click the Submit request button to ask the AI to perform the change.

You can repeat this process until you're happy with the image. Nano Banana is normally very good at understanding your requests.

For instance, removing or adding elements in the image is down seamlessly, without damaging the underlying image.

Here is an example of image modification with the description we just entered:

Work images expire

All these generated and modified images are saved in a temporary location by 4AI. They are kept for 24 hours after being created/modified, and you can keep working on them during that length of time.

But to keep them permanently, you must use the Save Image... button before an image expire. If you do, 4AI will save that particular image in a specific folder on your server, and you'll be able to use it from the Joomla media manager just like any other image.