OpenAI - Image

OpenAI’s image API allows us to use the models used for DallE. The API can be used to create, edit and make image variations.

[prompt] -> OpenAI Image API -> [image]

Http API

Using CURL we can ask the image API to generate an image:

export OPENAI_KEY="<your-key-here>"
curl https://api.openai.com/v1/images/generations \
  -H 'Content-Type: application/json' \
  -H 'Authorization: Bearer '$OPENAI_KEY'' \
  -d '{
  "prompt": "a boss monster in pixel art",
  "size": "256x256"
}'

The response will look something like:

{
  "created": 1678345154,
  "data": [
    {
      "url": "https://oaidalleapiprodscus...."
    }
  ]
}

In my case, the image was:

API Key

To get an API Key, create an OpenAI account, you can generate tokens under your profile.

Parameters

There are several parameters we can manipulate when we make a call to images API.

response_format

This determines whether we get a URL or a base64 encoded message. The go example below demonstrates using base64 which helps when we want to same the image to file immediately.

size

Currently, the API supports "256x256", "512x512" and "1024x1024"

n

n allows us to set the number of choices the API provides. It is 1 by default.

user

user allows you to set a user id for the callee. This allows the API to track users which are using the API to make inappropriate requests which are outside of OpenAI’s usage policies.

---

Examples

Export your API key as an environment variable:

export OPENAI_KEY="<your-key-here>"

Go

In this example, we explicitly ask for a base64 response, and save the image to file immediately.

package main

import (
  "context"
  "encoding/base64"
  "os"

  openai "github.com/sashabaranov/go-openai"
)

func main() {
  c := openai.NewClient(os.Getenv("OPENAI_KEY"))
  ctx := context.Background()

  req := openai.ImageRequest{
    Prompt:         "Pikachu becoming a tennis champion",
    Size:           openai.CreateImageSize512x512,
    ResponseFormat: openai.CreateImageResponseFormatB64JSON,
  }

  resp, err := c.CreateImage(ctx, req)
  if err != nil {
    panic(err)
  }

  b, err := base64.StdEncoding.DecodeString(resp.Data[0].B64JSON)
  if err != nil {
    panic(err)
  }

  f, err := os.Create("pikachamp.png")
  if err != nil {
    panic(err)
  }
  defer f.Close()

  _, err = f.Write(b)
  if err != nil {
    panic(err)
  }
}

Some of the results were a little bit offputting, but this one looks good:

Python

pip3 install openai

import os
import openai

openai.api_key = os.getenv("OPENAI_KEY")

response = openai.Image.create(
    prompt="A cartoon rabbit in a snowfield",
    n=1,
    size="512x512"
)
print(response['data'][0]['url'])

Resulted in the following image: