app.py

import gradio as gr
import torch
from transformers import AutoFeatureExtractor, AutoModelForImageClassification, pipeline
import os
import zipfile
import shutil
import matplotlib.pyplot as plt
from sklearn.metrics import accuracy_score, roc_auc_score, confusion_matrix, classification_report, roc_curve, auc, ConfusionMatrixDisplay
from PIL import Image
import tempfile
import numpy as np
import urllib.request
import base64
from io import BytesIO

MODEL_NAME = "cmckinle/sdxl-flux-detector"
LABELS = ["AI", "Real"]

class AIDetector:
    def __init__(self):
        self.pipe = pipeline("image-classification", MODEL_NAME)
        self.feature_extractor = AutoFeatureExtractor.from_pretrained(MODEL_NAME)
        self.model = AutoModelForImageClassification.from_pretrained(MODEL_NAME)

    @staticmethod
    def softmax(vector):
        e = np.exp(vector - np.max(vector))
        return e / e.sum()

    def predict(self, image):
        inputs = self.feature_extractor(image, return_tensors="pt")
        with torch.no_grad():
            outputs = self.model(**inputs)
            logits = outputs.logits
            probabilities = self.softmax(logits.numpy())
        
        prediction = logits.argmax(-1).item()
        label = LABELS[prediction]
        
        results = {label: float(prob) for label, prob in zip(LABELS, probabilities[0])}
        
        return label, results

def process_zip(zip_file):
    temp_dir = tempfile.mkdtemp()
    
    try:
        # Validate zip structure
        with zipfile.ZipFile(zip_file.name, 'r') as z:
            file_list = z.namelist()
            if not ('real/' in file_list and 'ai/' in file_list):
                raise ValueError("Zip file must contain 'real' and 'ai' folders")
            
            z.extractall(temp_dir)
        
        labels, preds, images = [], [], []
        false_positives, false_negatives = [], []
        detector = AIDetector()
        
        total_images = sum(len(files) for _, _, files in os.walk(temp_dir))
        processed_images = 0
        
        for folder_name, ground_truth_label in [('real', 1), ('ai', 0)]:
            folder_path = os.path.join(temp_dir, folder_name)
            if not os.path.exists(folder_path):
                raise ValueError(f"Folder not found: {folder_path}")
            
            for img_name in os.listdir(folder_path):
                img_path = os.path.join(folder_path, img_name)
                try:
                    with Image.open(img_path).convert("RGB") as img:
                        _, prediction = detector.predict(img)
                    
                    pred_label = 0 if prediction["AI"] > prediction["Real"] else 1
                    
                    preds.append(pred_label)
                    labels.append(ground_truth_label)
                    images.append(img_name)

                    # Collect false positives and false negatives with image data
                    if pred_label != ground_truth_label:
                        with open(img_path, "rb") as img_file:
                            img_data = base64.b64encode(img_file.read()).decode()
                        if pred_label == 1 and ground_truth_label == 0:
                            false_positives.append((img_name, img_data))
                        elif pred_label == 0 and ground_truth_label == 1:
                            false_negatives.append((img_name, img_data))

                except Exception as e:
                    print(f"Error processing image {img_name}: {e}")
                
                processed_images += 1
                gr.Progress(processed_images / total_images)
        
        return evaluate_model(labels, preds, false_positives, false_negatives)
    
    except Exception as e:
        raise gr.Error(f"Error processing zip file: {str(e)}")
    
    finally:
        shutil.rmtree(temp_dir)

def format_classification_report(labels, preds):
    # Convert the report string to a dictionary
    report_dict = classification_report(labels, preds, output_dict=True)
    
    # Create an HTML table with updated CSS
    html = """
    <style>
        .report-table {
            border-collapse: collapse;
            width: 100%;
            font-family: Arial, sans-serif;
        }
        .report-table th, .report-table td {
            border: 1px solid;
            padding: 8px;
            text-align: center;
        }
        .report-table th {
            font-weight: bold;
        }
        .report-table tr:nth-child(even) {
            background-color: rgba(0, 0, 0, 0.05);
        }
        @media (prefers-color-scheme: dark) {
            .report-table {
                color: #e0e0e0;
                background-color: #2d2d2d;
            }
            .report-table th, .report-table td {
                border-color: #555;
            }
            .report-table th {
                background-color: #3d3d3d;
            }
            .report-table tr:nth-child(even) {
                background-color: #333;
            }
            .report-table tr:hover {
                background-color: #3a3a3a;
            }
        }
        @media (prefers-color-scheme: light) {
            .report-table {
                color: #333333;
                background-color: #ffffff;
            }
            .report-table th, .report-table td {
                border-color: #ddd;
            }
            .report-table th {
                background-color: #f2f2f2;
            }
            .report-table tr:nth-child(even) {
                background-color: #f9f9f9;
            }
            .report-table tr:hover {
                background-color: #f5f5f5;
            }
        }
    </style>
    <table class="report-table">
        <tr>
            <th>Class</th>
            <th>Precision</th>
            <th>Recall</th>
            <th>F1-Score</th>
            <th>Support</th>
        </tr>
    """
    
    # Add rows for each class
    for class_name in ['0', '1']:
        html += f"""
        <tr>
            <td>{class_name}</td>
            <td>{report_dict[class_name]['precision']:.2f}</td>
            <td>{report_dict[class_name]['recall']:.2f}</td>
            <td>{report_dict[class_name]['f1-score']:.2f}</td>
            <td>{report_dict[class_name]['support']}</td>
        </tr>
        """
    
    # Add summary rows
    html += f"""
        <tr>
            <td>Accuracy</td>
            <td colspan="3">{report_dict['accuracy']:.2f}</td>
            <td>{report_dict['macro avg']['support']}</td>
        </tr>
        <tr>
            <td>Macro Avg</td>
            <td>{report_dict['macro avg']['precision']:.2f}</td>
            <td>{report_dict['macro avg']['recall']:.2f}</td>
            <td>{report_dict['macro avg']['f1-score']:.2f}</td>
            <td>{report_dict['macro avg']['support']}</td>
        </tr>
        <tr>
            <td>Weighted Avg</td>
            <td>{report_dict['weighted avg']['precision']:.2f}</td>
            <td>{report_dict['weighted avg']['recall']:.2f}</td>
            <td>{report_dict['weighted avg']['f1-score']:.2f}</td>
            <td>{report_dict['weighted avg']['support']}</td>
        </tr>
    </table>
    """
    
    return html
    
def evaluate_model(labels, preds, false_positives, false_negatives):
    cm = confusion_matrix(labels, preds)
    accuracy = accuracy_score(labels, preds)
    roc_score = roc_auc_score(labels, preds)
    report_html = format_classification_report(labels, preds)
    fpr, tpr, _ = roc_curve(labels, preds)
    roc_auc = auc(fpr, tpr)

    fig, (ax1, ax2) = plt.subplots(1, 2, figsize=(15, 6))
    
    ConfusionMatrixDisplay(confusion_matrix=cm, display_labels=LABELS).plot(cmap=plt.cm.Blues, ax=ax1)
    ax1.set_title("Confusion Matrix")
    
    ax2.plot(fpr, tpr, color='blue', lw=2, label=f'ROC curve (area = {roc_auc:.2f})')
    ax2.plot([0, 1], [0, 1], color='gray', linestyle='--')
    ax2.set_xlim([0.0, 1.0])
    ax2.set_ylim([0.0, 1.05])
    ax2.set_xlabel('False Positive Rate')
    ax2.set_ylabel('True Positive Rate')
    ax2.set_title('ROC Curve')
    ax2.legend(loc="lower right")
    
    plt.tight_layout()

    # Create HTML for false positives and negatives with images
    fp_fn_html = """
    <style>
        .image-grid {
            display: flex;
            flex-wrap: wrap;
            gap: 10px;
        }
        .image-item {
            display: flex;
            flex-direction: column;
            align-items: center;
        }
        .image-item img {
            max-width: 200px;
            max-height: 200px;
        }
    </style>
    """

    fp_fn_html += "<h3>False Positives (AI images classified as Real):</h3>"
    fp_fn_html += '<div class="image-grid">'
    for img_name, img_data in false_positives:
        fp_fn_html += f'''
        <div class="image-item">
            <img src="data:image/jpeg;base64,{img_data}" alt="{img_name}">
            <p>{img_name}</p>
        </div>
        '''
    fp_fn_html += '</div>'

    fp_fn_html += "<h3>False Negatives (Real images classified as AI):</h3>"
    fp_fn_html += '<div class="image-grid">'
    for img_name, img_data in false_negatives:
        fp_fn_html += f'''
        <div class="image-item">
            <img src="data:image/jpeg;base64,{img_data}" alt="{img_name}">
            <p>{img_name}</p>
        </div>
        '''
    fp_fn_html += '</div>'

    return accuracy, roc_score, report_html, fig, fp_fn_html

def load_url(url):
    try:
        urllib.request.urlretrieve(url, "temp_image.png")
        image = Image.open("temp_image.png")
        message = "Image Loaded"
    except Exception as e:
        image = None
        message = f"Image not Found<br>Error: {e}"
    return image, message

detector = AIDetector()

def create_gradio_interface():
    with gr.Blocks() as app:
        gr.Markdown("""<center><h1>AI Image Detector<br><h4>(Test Demo - accuracy varies by model)</h4></h1></center>""")

        with gr.Tabs():
            with gr.Tab("Single Image Detection"):
                with gr.Column():
                    inp = gr.Image(type='pil')
                    in_url = gr.Textbox(label="Image URL")
                    with gr.Row():
                        load_btn = gr.Button("Load URL")
                        btn = gr.Button("Detect AI")
                    message = gr.HTML()

                with gr.Group():
                    with gr.Box():
                        gr.HTML(f"""<b>Testing on Model: <a href='https://huggingface.co/{MODEL_NAME}'>{MODEL_NAME}</a></b>""")
                        output_html = gr.HTML()
                        output_label = gr.Label(label="Output")

            with gr.Tab("Batch Image Processing"):
                zip_file = gr.File(
                    label="Upload Zip (must contain 'real' and 'ai' folders)",
                    file_types=[".zip"],
                    file_count="single",
                    max_file_size=1024  # 1024 MB (1 GB)
                )
                batch_btn = gr.Button("Process Batch", interactive=False)

                with gr.Group():
                    gr.Markdown(f"### Results for {MODEL_NAME}")
                    output_acc = gr.Label(label="Accuracy")
                    output_roc = gr.Label(label="ROC Score")
                    output_report = gr.HTML(label="Classification Report")
                    output_plots = gr.Plot(label="Confusion Matrix and ROC Curve")
                    output_fp_fn = gr.HTML(label="False Positives and Negatives")

        load_btn.click(load_url, in_url, [inp, message])
        btn.click(
            lambda img: detector.predict(img),
            inp,
            [output_html, output_label]
        )

        def enable_batch_btn(file):
            return gr.Button.update(interactive=file is not None)

        zip_file.upload(
            enable_batch_btn,
            zip_file,
            batch_btn
        )

        batch_btn.click(
            process_zip,
            zip_file,
            [output_acc, output_roc, output_report, output_plots, output_fp_fn],
            api_name="batch_process"
        )

    return app

if __name__ == "__main__":
    app = create_gradio_interface()
    app.launch(show_api=False, max_threads=24)