app.py

import torch
from transformers import AutoImageProcessor, Dinov2ForImageClassification, Dinov2Config, Dinov2Model
from PIL import Image
import gradio as gr
from huggingface_hub import hf_hub_download
import json
import torch.nn as nn
import numpy as np

# DEFINE MODEL NAME
model_name = "DinoVdeau_Aina-large-2024_06_12-batch-size32_epochs150_freeze"
checkpoint_name = "lombardata/" + model_name

# Load the model configuration and create the model
config_path = hf_hub_download(repo_id=checkpoint_name, filename="config.json")
with open(config_path, 'r') as config_file:
    config = json.load(config_file)
id2label = config["id2label"]
label2id = config["label2id"]
image_size = config["image_size"]
num_labels = len(id2label)

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

# IMPORT CLASSIFICATION MODEL
def create_head(num_features , number_classes ,dropout_prob=0.5 ,activation_func =nn.ReLU):
    features_lst = [num_features , num_features//2 , num_features//4]
    layers = []
    for in_f ,out_f in zip(features_lst[:-1] , features_lst[1:]):
        layers.append(nn.Linear(in_f , out_f))
        layers.append(activation_func())
        layers.append(nn.BatchNorm1d(out_f))
        if dropout_prob !=0 : layers.append(nn.Dropout(dropout_prob))
    layers.append(nn.Linear(features_lst[-1] , number_classes))
    return nn.Sequential(*layers)

class NewheadDinov2ForImageClassification(Dinov2ForImageClassification):
    def __init__(self, config: Dinov2Config) -> None:
        super().__init__(config)

        # Classifier head
        self.classifier = create_head(config.hidden_size * 2, config.num_labels)
        
model = NewheadDinov2ForImageClassification.from_pretrained(checkpoint_name)
model.to(device)
def sigmoid(_outputs):
    return 1.0 / (1.0 + np.exp(-_outputs))

def predict(image, slider_threshold=0.5, fixed_thresholds=None):
    # Preprocess the image
    processor = AutoImageProcessor.from_pretrained(checkpoint_name)
    inputs = processor(images=image, return_tensors="pt").to(device)
    
    # Get model predictions
    with torch.no_grad():
        model_outputs = model(**inputs)
    logits = model_outputs.logits[0]
    probabilities = torch.sigmoid(logits).cpu().numpy()  # Convert to probabilities

    # Create a dictionary of label scores based on the slider threshold
    slider_results = {id2label[str(i)]: float(prob) for i, prob in enumerate(probabilities) if prob > slider_threshold}
    
    # If fixed thresholds are provided, format the labels into a string
    fixed_threshold_labels_str = None
    if fixed_thresholds is not None:
        fixed_threshold_labels = [id2label[str(i)] for i, prob in enumerate(probabilities) if prob > fixed_thresholds[id2label[str(i)]]]
        fixed_threshold_labels_str = ", ".join(fixed_threshold_labels)

    return slider_results, fixed_threshold_labels_str

def predict_wrapper(image, slider_threshold=0.5):    
    # Get predictions from the predict function using both the slider and fixed thresholds
    slider_results, fixed_threshold_results = predict(image, slider_threshold)
    
    # Return both sets of predictions for Gradio outputs
    return slider_results, fixed_threshold_results


# Define style
title = "Aina image classification"
model_link = "https://huggingface.co/" + checkpoint_name
description = f"This application showcases the capability of artificial intelligence-based systems to identify objects within underwater images. To utilize it, you can either upload your own image or select one of the provided examples for analysis.\nFor predictions, we use this [open-source model]({model_link})"
description = ("This application showcases the capability of artificial intelligence-based systems "
               "to identify objects within underwater images. To utilize it, you can either upload "
               "your own image or select one of the provided examples for analysis. "
               "\nFor predictions, we use this [open-source model](model_link)")
# New subtitle message to be added
subtitle = "Note: the model runs on CPU, so it may take a while to run the prediction."
# Combine description and subtitle
full_description = f"{description}\n\n{subtitle}"

iface = gr.Interface(
    fn=predict_wrapper,
    inputs=[gr.components.Image(type="pil"), gr.components.Slider(minimum=0.0, maximum=1.0, value=0.5, label="Threshold")],
    outputs=[
        gr.components.Textbox(label="Fixed Threshold Predictions")
    ],
    title=title, 
    description=full_description).launch()