app.py

# app.py
import gradio as gr
from PIL import Image, ImageDraw, ImageFont
from ultralytics import YOLO
import numpy as np
import os

MODEL_PATH = "model/231220_detect_lr_0001_640_brightness.pt"

if not os.path.exists(MODEL_PATH):
    raise FileNotFoundError(f"YOLO model not found at '{MODEL_PATH}'.")
model = YOLO(MODEL_PATH)
print("YOLO model loaded.")

def detect_plastic_pellets(input_image, threshold=0.5):
    """
    Perform plastic pellet detection using our customized YOLO model.
    Returns the processed image and the number of detections.
    """
    if input_image is None:
        error_image = Image.new('RGB', (500, 100), color=(255, 0, 0))
        draw = ImageDraw.Draw(error_image)
        try:
            font = ImageFont.truetype("arial.ttf", size=15)
        except IOError:
            font = ImageFont.load_default()
        draw.text((10, 40), "Please upload a valid image.", fill=(255, 255, 255), font=font)
        return error_image, 0  # Returning 0 detections

    try:
        print("Starting detection with threshold:", threshold)
        input_image.thumbnail((1024, 1024), Image.LANCZOS)
        img = np.array(input_image.convert("RGB"))

        results = model(img)
        draw = ImageDraw.Draw(input_image)
        try:
            font = ImageFont.truetype("arial.ttf", size=15)
        except IOError:
            font = ImageFont.load_default()

        detection_made = False
        detection_count = 0  # Initialize detection count

        for result in results:
            for box in result.boxes:
                confidence = box.conf[0].item()
                if confidence < threshold:
                    continue  

                x1, y1, x2, y2 = map(int, box.xyxy[0].tolist())
                cls = int(box.cls[0].item())
                name = model.names[cls] if model.names else "Object"

                color = (255, 0, 0)
                draw.rectangle(((x1, y1), (x2, y2)), outline=color, width=2)

                label = f"{name} {confidence:.2f}"
                text_width, text_height = font.getbbox(label)[2:]
                # Ensure text does not go above the image
                text_y = max(y1 - text_height, 0)
                draw.rectangle(((x1, text_y), (x1 + text_width, y1)), fill=color)
                draw.text((x1, text_y), label, fill=(255, 255, 255), font=font)

                detection_made = True
                detection_count += 1  # Increment detection count

        if not detection_made:
            draw.text((10, 10), "No plastic pellets detected.", fill=(255, 0, 0), font=font)
        
        print("Detection completed. Total detections:", detection_count)
        return input_image, detection_count

    except Exception as e:
        print(f"Detection error: {str(e)}")
        error_image = Image.new('RGB', (500, 100), color=(255, 0, 0))
        draw = ImageDraw.Draw(error_image)
        try:
            font = ImageFont.truetype("arial.ttf", size=15)
        except IOError:
            font = ImageFont.load_default()
        draw.text((10, 40), f"Error: {str(e)}", fill=(255, 255, 255), font=font)
        return error_image, 0  # Returning 0 detections on error

def main():
    with gr.Blocks(css=".gradio-container {max-width: 800px}") as demo:
        gr.Markdown(
            """
            <h1 align="center">🌊 Beach Plastic Pellet Detection Challenge</h1>
            <p align="center">Help us clean up beaches from plastic pellets! Upload your beach photos or choose from our samples, and contribute to data collection for a cleaner environment.</p>
            """
        )

        with gr.Row():
            with gr.Column():
                input_image = gr.Image(type="pil", label="🌊 Upload or Select Beach Image", interactive=True)
                examples = [
                    'images/image1.bmp',
                    'images/image2.bmp',
                    'images/image3.bmp',
                    'images/image4.bmp',
                    'images/image5.bmp',
                    'images/image6.bmp'
                ]
                gr.Examples(examples=examples, inputs=input_image, label="Or choose one of these images")
                
                # Slider for confidence threshold
                confidence_threshold = gr.Slider(
                    minimum=0.0,
                    maximum=1.0,
                    value=0.5,
                    step=0.05,
                    label="Confidence Threshold",
                    info="Adjust the confidence threshold for displaying detections."
                )
                
                submit_button = gr.Button("🔍 Detect Plastic Pellets")

            with gr.Column():
                output_image = gr.Image(
                    type="pil",
                    label="✅ Detection Result",
                    interactive=False,
                    show_download_button=True
                )
                detection_count = gr.Text(
                    value="Detections: 0",
                    label="🔢 Number of Detections",
                    interactive=False
                )

        gr.Markdown(
            """
            ---
            <p align="center">© 2024 Beach Clean-Up Initiative.</p>
            """
        )

        submit_button.click(
            fn=detect_plastic_pellets,
            inputs=[input_image, confidence_threshold],
            outputs=[output_image, detection_count],  
            api_name="detect",
            show_progress=True  
        )

    demo.launch()

if __name__ == "__main__":
    main()