Bounding box detection

In this experimental launch, we are providing developers with a powerful tool for object detection and localization within images and video. By accurately identifying and delineating objects with bounding boxes, developers can unlock a wide range of applications and enhance the intelligence of their projects.

Key Benefits:

  • Simple: Integrate object detection capabilities into your applications with ease, regardless of your computer vision expertise.
  • Customizable: Produce bounding boxes based on custom instructions (e.g. "I want to see bounding boxes of all the green objects in this image"), without having to train a custom model.

Technical Details:

  • Input: Your prompt and associated images or video frames.
  • Output: Bounding boxes in the [y_min, x_min, y_max, x_max] format. The top left corner is the origin. The x and y axis go horizontally and vertically, respectively. Coordinate values are normalized to 0-1000 for every image.
  • Visualization: AI Studio users will see bounding boxes plotted within the UI. Vertex AI users should visualize their bounding boxes through custom visualization code.

Gen AI SDK for Python

Install

pip install --upgrade google-genai
 To learn more, see the SDK reference documentation.

Set environment variables to use the Gen AI SDK with Vertex AI: 

# Replace the `GOOGLE_CLOUD_PROJECT` and `GOOGLE_CLOUD_LOCATION` values
# with appropriate values for your project.
export GOOGLE_CLOUD_PROJECT=GOOGLE_CLOUD_PROJECT
export GOOGLE_CLOUD_LOCATION=us-central1
export GOOGLE_GENAI_USE_VERTEXAI=True
 

import requests

from google import genai
from google.genai.types import (
    GenerateContentConfig,
    HttpOptions,
    Part,
    SafetySetting,
)

from PIL import Image, ImageColor, ImageDraw

from pydantic import BaseModel

class BoundingBox(BaseModel):
    """
    Represents a bounding box with its 2D coordinates and associated label.

    Attributes:
        box_2d (list[int]): A list of integers representing the 2D coordinates of the bounding box,
                            typically in the format [x_min, y_min, x_max, y_max].
        label (str): A string representing the label or class associated with the object within the bounding box.
    """

    box_2d: list[int]
    label: str

def plot_bounding_boxes(image_uri: str, bounding_boxes: list[BoundingBox]) -> None:
    """
    Plots bounding boxes on an image with markers for each a name, using PIL, normalized coordinates, and different colors.

    Args:
        img_path: The path to the image file.
        bounding_boxes: A list of bounding boxes containing the name of the object
        and their positions in normalized [y1 x1 y2 x2] format.
    """

    with Image.open(requests.get(image_uri, stream=True, timeout=10).raw) as im:
        width, height = im.size
        draw = ImageDraw.Draw(im)

        colors = list(ImageColor.colormap.keys())

        for i, bbox in enumerate(bounding_boxes):
            y1, x1, y2, x2 = bbox.box_2d
            abs_y1 = int(y1 / 1000 * height)
            abs_x1 = int(x1 / 1000 * width)
            abs_y2 = int(y2 / 1000 * height)
            abs_x2 = int(x2 / 1000 * width)

            color = colors[i % len(colors)]

            draw.rectangle(
                ((abs_x1, abs_y1), (abs_x2, abs_y2)), outline=color, width=4
            )
            if bbox.label:
                draw.text((abs_x1 + 8, abs_y1 + 6), bbox.label, fill=color)

        im.show()

client = genai.Client(http_options=HttpOptions(api_version="v1"))

config = GenerateContentConfig(
    system_instruction="""
    Return bounding boxes as an array with labels.
    Never return masks. Limit to 25 objects.
    If an object is present multiple times, give each object a unique label
    according to its distinct characteristics (colors, size, position, etc..).
    """,
    temperature=0.5,
    safety_settings=[
        SafetySetting(
            category="HARM_CATEGORY_DANGEROUS_CONTENT",
            threshold="BLOCK_ONLY_HIGH",
        ),
    ],
    response_mime_type="application/json",
    response_schema=list[BoundingBox],
)

image_uri = "https://storage.googleapis.com/generativeai-downloads/images/socks.jpg"

response = client.models.generate_content(
    model="gemini-2.0-flash-001",
    contents=[
        Part.from_uri(
            file_uri=image_uri,
            mime_type="image/jpeg",
        ),
        "Output the positions of the socks with a face. Label according to position in the image.",
    ],
    config=config,
)
print(response.text)
plot_bounding_boxes(image_uri, response.parsed)

# Example response:
# [
#     {"box_2d": [36, 246, 380, 492], "label": "top left sock with face"},
#     {"box_2d": [260, 663, 640, 917], "label": "top right sock with face"},
# ]