app.py

import streamlit as st
from model import load_model, process_and_predict
from landmarks import normalize_landmarks, calculate_angles
from visualization import plot_hand_landmarks
import os

st.set_page_config(layout="wide")

# Define the alphabets
all_alphabets = 'ABCDEFGHIJKLMNOPQRSTUVWXYZ'
excluded_alphabets = 'DMNPTUVXZ'
working_alphabets = ''.join(set(all_alphabets) - set(excluded_alphabets))

# README content
readme_content = f"""
## How it works

This ASL Recognition App uses image processing and machine learning to recognize American Sign Language (ASL) hand signs.

1. **Image Upload**: Users can upload an image of an ASL hand sign.
2. **Hand Detection**: The app uses MediaPipe to detect hand landmarks in the image.
3. **Feature Extraction**: Angles between hand landmarks are calculated and normalized.
4. **Prediction**: A Random Forest model predicts the ASL sign based on the extracted features.
5. **Visualization**: The app displays the detected hand landmarks and top predictions.

### Supported Alphabets

The app currently works for the following ASL alphabets:
{', '.join(working_alphabets)}

The app does not support or may not work correctly for:
{', '.join(excluded_alphabets)}

Note: The model's performance may vary and is subject to improvement.

The "View Hand Landmarks" tab allows users to see hand landmarks for pre-loaded ASL signs.
"""

# Load the model
model = load_model()

# Ensure the model is loaded before proceeding
if model is None:
    st.stop()

# Streamlit app
st.title("ASL Recognition App")

# Display README content
st.sidebar.markdown(readme_content)

# Create tabs for different functionalities
tab1, tab2 = st.tabs(["Predict ASL Sign", "View Hand Landmarks"])

with tab1:
    st.header("Predict ASL Sign")
    uploaded_file = st.file_uploader("Upload an image of an ASL sign", type=["jpg", "jpeg", "png"])

    if uploaded_file is not None:
        try:
            image = cv2.imdecode(np.frombuffer(uploaded_file.read(), np.uint8), 1)
            if image is not None:
                col1, col2 = st.columns(2)
                with col1:
                    st.image(image, caption="Uploaded Image", use_column_width=True)
                
                probabilities, landmarks = process_and_predict(image)
                
                if probabilities is not None and landmarks is not None:
                    with col2:
                        st.subheader("Top 5 Predictions:")
                        top_indices = np.argsort(probabilities)[::-1][:5]
                        for i in top_indices:
                            st.write(f"{model.classes_[i]}: {probabilities[i]:.2f}")
                    
                    fig = plot_hand_landmarks(landmarks, "Detected Hand Landmarks")
                    st.pyplot(fig)
                else:
                    st.write("No hand detected in the image.")
            else:
                st.error("Failed to load the image. The file might be corrupted.")
        except Exception as e:
            st.error(f"An error occurred while processing the image: {str(e)}")

with tab2:
    st.header("View Hand Landmarks")
    
    selected_alphabets = st.multiselect("Select alphabets to view landmarks:", list(working_alphabets))

    if selected_alphabets:
        cols = st.columns(4)  # 4 columns for smaller images
        for idx, alphabet in enumerate(selected_alphabets):
            with cols[idx % 4]:
                image_path = os.path.join('asl test set', f'{alphabet.lower()}.jpeg')
                if os.path.exists(image_path):
                    try:
                        image = cv2.imread(image_path)
                        if image is not None:
                            probabilities, landmarks = process_and_predict(image)
                            if landmarks is not None:
                                fig = plot_hand_landmarks(landmarks, f"Hand Landmarks for {alphabet}")
                                st.pyplot(fig)
                            else:
                                st.error(f"No hand detected for {alphabet}")
                        else:
                            st.error(f"Failed to load image for {alphabet}")
                    except Exception as e:
                        st.error(f"Error processing image for {alphabet}")
                else:
                    st.error(f"Image not found for {alphabet}")