app.py

import gradio as gr
from jiwer import wer, process_words

def make_string(words):
    return " ".join(words)

# Function to highlight errors
def highlight_errors(ground_truth, hypothesis):

    highlighted_text = []

    processed = process_words(ground_truth, hypothesis)

    # Process each alignment operation in measures
    for alignment, ref, hyp in zip(processed.alignments, processed.references, processed.hypotheses):
        for chunk in alignment:
            if chunk.type == 'equal':
                # Add equal words without highlighting
                highlighted_text.extend(ref[chunk.ref_start_idx:chunk.ref_end_idx])

            elif chunk.type == 'insert':
                # Highlight inserted words in green
                highlighted_text.append(f'<span style="color:green;">{make_string(hyp[chunk.hyp_start_idx:chunk.hyp_end_idx])}</span>')

            elif chunk.type == 'substitute':
                # Highlight substitutions in purple: ground truth is striked through
                highlighted_text.append(f'<span style="color:purple;">{make_string(hyp[chunk.hyp_start_idx:chunk.hyp_end_idx])}</span>')  # Hypothesis word
                highlighted_text.append(f'<span style="color:purple; text-decoration:line-through;">{make_string(ref[chunk.ref_start_idx:chunk.ref_end_idx])}</span>')  # Ground truth word

            elif chunk.type == 'delete':
                # Highlight deleted words in red with strikethrough
                highlighted_text.append(f'<span style="color:red; text-decoration:line-through;">{make_string(ref[chunk.ref_start_idx:chunk.ref_end_idx])}</span>')

    highlighted_text_str = ' '.join(highlighted_text)
    
    # Color Legend HTML
    legend_html = """
    <div style="margin-top: 10px;">
        <strong>Legend</strong><br>
        <span style="color:green;">Insertion</span>: Green<br>
        <span style="color:purple;">Substitution</span>: Purple<br>
        <span style="color:red; text-decoration:line-through;">Deletion</span>: Red<br>
    </div>
    """

    # Combine highlighted output and legend
    combined_output = f"{legend_html}<br>{highlighted_text_str}"

    return combined_output, processed.wer, processed.substitutions, processed.insertions, processed.deletions

# Gradio Interface
interface = gr.Interface(
    fn=highlight_errors,
    inputs=["text", "text"],
    outputs=[
        gr.HTML(label="Highlighted Transcript"),
        gr.Number(label="Word Error Rate"),
        gr.Number(label="Substitutions"),
        gr.Number(label="Insertions"),
        gr.Number(label="Deletions")
    ],
    title="WER Analysis"
)

interface.launch()