app.py

import gradio as gr
from PIL import Image
from zopflipng import png_optimize
import os

def convert_webp(input_path, compression_level=6, lossless_mode=False):
    """Convert WEBP to PNG with compression options and Zopfli optimization"""
    try:
        # Convert WEBP to temporary PNG
        with Image.open(input_path) as img:
            temp_path = "temp.png"
            img.convert("RGB").save(
                temp_path,
                format="PNG",
                compress_level=compression_level,
                optimize=True
            )
            
        # Apply ZopfliPNG optimization if enabled
        if lossless_mode:
            with open(temp_path, "rb") as f:
                original_data = f.read()
            
            optimized_data, code = png_optimize(
                original_data,
                num_iterations=15,
                lossy_8bit=False,
                lossy_transparent=False
            )
            
            if code == 0:
                with open(temp_path, "wb") as f:
                    f.write(optimized_data)
            else:
                raise RuntimeError("ZopfliPNG optimization failed")

        return temp_path
    
    except Exception as e:
        raise gr.Error(f"Conversion failed: {str(e)}")

# Create Gradio interface
with gr.Blocks(title="WEBP to PNG Professional Converter") as app:
    gr.Markdown("## 🔄 Professional WEBP to PNG Converter")
    
    with gr.Row():
        with gr.Column():
            input_img = gr.Image(
                type="filepath",
                label="Upload WEBP Image",
                height=300
            )
            comp_slider = gr.Slider(
                minimum=0,
                maximum=9,
                value=6,
                step=1,
                label="PNG Compression Level (0=fast, 9=small)",
                info="Standard DEFLATE compression"
            )
            lossless_toggle = gr.Checkbox(
                label="Enable Professional Lossless Mode (ZopfliPNG)",
                info="Advanced compression (slower but smaller files)"
            )
            convert_btn = gr.Button("Start Conversion", variant="primary")
        
        with gr.Column():
            output_img = gr.Image(
                label="Converted PNG Result",
                type="filepath",
                height=400,
                interactive=False
            )

    convert_btn.click(
        fn=convert_webp,
        inputs=[input_img, comp_slider, lossless_toggle],
        outputs=output_img
    )

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