app.py

import gradio as gr
import cv2
import numpy as np

def sepia_filter(image):
    """
    image comes in as a NumPy array (RGB)
    """
    # Convert RGB (Gradio) → BGR (OpenCV)
    image = cv2.cvtColor(image, cv2.COLOR_RGB2BGR)

    sepia_kernel = np.array([
        [0.272, 0.534, 0.131],
        [0.349, 0.686, 0.168],
        [0.393, 0.769, 0.189]
    ])

    sepia = cv2.transform(image, sepia_kernel)
    sepia = np.clip(sepia, 0, 255).astype(np.uint8)

    # Convert back BGR → RGB for Gradio
    sepia = cv2.cvtColor(sepia, cv2.COLOR_BGR2RGB)

    return sepia

app = gr.Interface(
    fn=sepia_filter,
    inputs=gr.Image(type="numpy", label="Input Image"),
    outputs=gr.Image(type="numpy", label="Sepia Output"),
    title="Simple Sepia Filter",
    description="Upload an image and apply a sepia filter using OpenCV."
)

if __name__ == "__main__":
    app.launch()