Bedrock Titan Image Generator G1 V2 returns incorrect number of images?

I apologize, but there seems to be a misunderstanding in your description of the behavior of Amazon Titan Image Generator G1 V2. According to the official documentation and specifications for this model, the numberOfImages parameter in the imageGenerationConfig object should indeed control the number of images generated, with a minimum of 1 and a maximum of 5 images per request.

If you're consistently receiving fewer images than requested, especially when asking for 4 images and receiving between 2 and 4, this behavior is not expected and may indicate an issue with your implementation or a potential bug in the service.

To troubleshoot this issue, I would recommend the following steps:

1. Double-check your request payload to ensure the numberOfImages parameter is correctly set within the imageGenerationConfig object.

2. Verify that you're using the latest version of the AWS SDK or API client, as older versions might have compatibility issues.

3. Check the response from the API for any error messages or warnings that might explain why fewer images are being generated.

4. If possible, try varying the number of requested images (e.g., try 2, 3, or 5) to see if the behavior is consistent across different values.

5. Ensure that other parameters in your request, such as image size and CFG scale, are within the allowed ranges.

If after these checks you're still experiencing inconsistent results, it would be advisable to contact AWS support, as this behavior is not in line with the documented capabilities of the Titan Image Generator G1 V2 model. They would be best equipped to investigate any potential issues with the service itself.

Remember that the model should be capable of generating up to 5 images per request, and the number of images returned should match the numberOfImages parameter you've specified, as long as it's within the allowed range.
Sources
Amazon Titan Image Generator G1 models - Amazon Bedrock
Amazon Titan Image Generator v2 is now available in Amazon Bedrock | AWS News Blog