app.py

import torch
import torch.nn as nn
from torchvision import models, transforms as T
from PIL import Image
import gradio as gr

device = torch.device("cuda" if torch.cuda.is_available() else "cpu")

# Load label files
wnids = [line.strip() for line in open("wnids.txt")]

# Map wnid → readable label
words = {}
with open("words.txt", "r") as f:
    for line in f:
        wnid, name = line.split("\t")
        words[wnid] = name.split(",")[0]

# ✅ CORRECT CLASS ORDER (alphabetical)
sorted_wnids = sorted(wnids)

# ✅ Final label list matching model training order
id_to_label = [words[wnid] for wnid in sorted_wnids]

# Load Model
model = models.resnet18(weights=None)
model.fc = nn.Linear(model.fc.in_features, 200)
model.load_state_dict(torch.load("best_resnet18_tinyimagenet.pth", map_location=device))
model.to(device)
model.eval()

# Same preprocessing as training
transform = T.Compose([
    T.Resize((224, 224)),
    T.ToTensor(),
    T.Normalize((0.485, 0.456, 0.406),
                (0.229, 0.224, 0.225))
])

def predict(image):
    image = transform(image).unsqueeze(0).to(device)
    with torch.no_grad():
        logits = model(image)
    pred = logits.argmax(1).item()
    return id_to_label[pred]

gr.Interface(
    fn=predict,
    inputs=gr.Image(type="pil"),
    outputs="text",
    title="Tiny ImageNet Classifier (Corrected Labels)"
).launch()