Paste an Image URL and Let Gemini AI Describe It Instantly

This tutorial walks you through building a Python GUI app using Tkinter where users can paste an image URL and get a description using Google’s Gemini AI model.

Step 1: Import Required Libraries

import tkinter as tk
from tkinter import messagebox, scrolledtext
import requests
from PIL import Image
import io
import os
import google.generativeai as genai
from dotenv import load_dotenv

pip install google-generativeai python-dotenv

Step 2: Load and Configure Gemini API Key

# Load your API key securely from a .env file
load_dotenv()
GOOGLE_API_KEY = os.getenv("GOOGLE_API_KEY")

# Configure Gemini SDK
genai.configure(api_key=GOOGLE_API_KEY)

# Initialize Gemini model
model = genai.GenerativeModel('gemini-1.5-flash')

Step 3: Define the Function to Handle Image Input and Gemini Output

def describe_image():
    image_url = url_entry.get().strip()
    if not image_url:
        messagebox.showwarning("Input Error", "Please enter an image URL.")
        return

    try:
        # Download the image
        response = requests.get(image_url)
        if response.status_code != 200:
            raise Exception("Failed to fetch image.")

        img = Image.open(io.BytesIO(response.content))

        # Convert image to JPEG bytes
        img_byte_arr = io.BytesIO()
        img.save(img_byte_arr, format='JPEG')
        img_bytes = img_byte_arr.getvalue()

        # Gemini expects image as a dict
        gemini_image = {
            "mime_type": "image/jpeg",
            "data": img_bytes
        }

        prompt = ["Describe the image", gemini_image]
        result = model.generate_content(prompt)

        output_box.delete('1.0', tk.END)
        output_box.insert(tk.END, result.text)

    except Exception as e:
        messagebox.showerror("Error", f"An error occurred:\n{e}")

Step 4: Create the Tkinter GUI

# Initialize main window
root = tk.Tk()
root.title("Image Description with Gemini")
root.geometry("600x400")

tk.Label(root, text="Enter Image URL:").pack(pady=10)

# Input for image URL
url_entry = tk.Entry(root, width=70)
url_entry.pack(pady=5)

# Button to trigger Gemini call
tk.Button(
    root,
    text="Describe Image",
    command=describe_image,
    bg="blue",
    fg="white"
).pack(pady=10)

tk.Label(root, text="Gemini Description:").pack(pady=5)

# ScrolledText to show Gemini's response
output_box = scrolledtext.ScrolledText(root, wrap=tk.WORD, height=10, width=70)
output_box.pack(padx=10, pady=10)

# Run the GUI event loop
root.mainloop()

🎯 Example Use

URL: https://upload.wikimedia.org/wikipedia/commons/thumb/5/59/Dog_in_field.jpg/800px-Dog_in_field.jpg

Gemini: "This is an image of a happy dog standing on green grass in an open field, looking toward the camera."

✅ Notes

• Make sure your image URL points directly to a .jpg file.
• You must have a valid Gemini API key stored in a .env file.
• This script uses Gemini 1.5 Flash for faster performance. You may switch to gemini-1.5-pro for richer responses.

Full Code

import tkinter as tk
from tkinter import messagebox, scrolledtext
import requests
from PIL import Image
import io
import os
import google.generativeai as genai
from dotenv import load_dotenv

# Load API key
load_dotenv()
GOOGLE_API_KEY = os.getenv("GOOGLE_API_KEY")

# Configure Gemini
genai.configure(api_key=GOOGLE_API_KEY)

# Initialize Gemini model
model = genai.GenerativeModel('gemini-1.5-flash')

def describe_image():
    image_url = url_entry.get().strip()
    if not image_url:
        messagebox.showwarning("Input Error", "Enter an image URL.")
        return

    try:
        # Download image
        response = requests.get(image_url)
        if response.status_code != 200:
            raise Exception("Failed to fetch image.")

        img = Image.open(io.BytesIO(response.content))

        # Convert image to bytes in JPEG format
        img_byte_arr = io.BytesIO()
        img.save(img_byte_arr, format='JPEG')
        img_bytes = img_byte_arr.getvalue()

        # Gemini expects image part in a specific format
        gemini_image = {
            "mime_type": "image/jpeg",
            "data": img_bytes
        }

        # Send to Gemini
        prompt = ["Describe the image", gemini_image]
        result = model.generate_content(prompt)

        output_box.delete('1.0', tk.END)
        output_box.insert(tk.END, result.text)

    except Exception as e:
        messagebox.showerror("Error", f"An error occurred:\n{e}")

# GUI Setup
root = tk.Tk()
root.title("Image Description with Gemini")
root.geometry("600x400")

tk.Label(root, text="Enter Image URL:").pack(pady=10)
url_entry = tk.Entry(root, width=70)
url_entry.pack(pady=5)

tk.Button(
    root, text="Describe Image", 
    command=describe_image, bg="blue", fg="white"
).pack(pady=10)

tk.Label(root, text="Gemini Description:").pack(pady=5)
output_box = scrolledtext.ScrolledText(root, wrap=tk.WORD, height=10, width=70)
output_box.pack(padx=10, pady=10)

root.mainloop()

Subhendu Mohapatra

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