Having trouble getting transparent backgrounds in ChatGPT images

ChatGPT says:

All parameters with a question mark are optional - and you still get an image with an empty JSON as merely a trigger (and contents by the AI model observing the conversation).

Notable is that there are…

Leaving the AI to guess using pretraining up to cutoff or post-training on tool calling, and to hallucinate that referenced image IDs still does anything or that more than one image could be delivered from this old tool spec.

So we specify. Notably, ChatGPT gives us no promise of what “model” is used, or if today you fall back to a cheap “mini” image creator that does support transparency, or a “beta”. What we do know is that gpt-image-1.5 that is the last API model to offer transparency, and it is limited to three sizes. So we specify, like the earlier poster’s insight

Notable is that there is no “n:4” being satisfied, but instead the image model that also views the entirety of the chat interprets the language I sent (and not the internal tool JSON) as making a grid of four.

However, success: the images are indeed transparent without any “post-coding”. Here they are in my application where this mustard color rarely seen is the background behind transparency.

The delivered and seen whites are a value about 252 of 255, which aligns with prior suspicions of transparency being a held-out brilliant white, programmatically removed by OpenAI (and prior images being that sepia filter color).

Final product for the forum: a GIF:

Notable is the crudeness of the AI image…

The lazy person even uses AI to make their JSON... (click for more details)