app.py

from io import BytesIO
import streamlit as st
import pandas as pd
import json
import os
import numpy as np
from streamlit.elements import markdown
from model.flax_clip_vision_bert.modeling_clip_vision_bert import FlaxCLIPVisionBertForSequenceClassification
from utils import get_transformed_image, get_text_attributes, get_top_5_predictions, plotly_express_horizontal_bar_plot, translate_labels
import matplotlib.pyplot as plt
from mtranslate import translate
from PIL import Image


from session import _get_state

state = _get_state()

@st.cache(persist=True)
def load_model(ckpt):
    return FlaxCLIPVisionBertForSequenceClassification.from_pretrained(ckpt)

@st.cache(persist=True)
def predict(transformed_image, question_inputs):
    return np.array(model(pixel_values = transformed_image, **question_inputs)[0][0])
    
def softmax(logits):
    return np.exp(logits)/np.sum(np.exp(logits), axis=0)

def read_markdown(path, parent="./sections/"):
    with open(os.path.join(parent,path)) as f:
        return f.read()

checkpoints = ['./ckpt/ckpt-60k-5999'] # TODO: Maybe add more checkpoints?
dummy_data = pd.read_csv('dummy_vqa_multilingual.tsv', sep='\t')
code_to_name = {
    "en": "English",
    "fr": "French",
    "de": "German",
    "es": "Spanish",
}

with open('answer_reverse_mapping.json') as f:
    answer_reverse_mapping = json.load(f)


st.set_page_config(
    page_title="Multilingual VQA",
    layout="wide",
    initial_sidebar_state="collapsed",
    page_icon="./misc/mvqa-logo.png",
)

st.title("Multilingual Visual Question Answering")
st.write("[Gunjan Chhablani](https://huggingface.co/gchhablani), [Bhavitvya Malik](https://huggingface.co/bhavitvyamalik)")

with st.beta_expander("Usage"):
    st.markdown(read_markdown("usage.md"))

first_index = 20
# Init Session State
if state.image_file is None:
    state.image_file = dummy_data.loc[first_index,'image_file']
    state.question = dummy_data.loc[first_index,'question'].strip('- ')
    state.answer_label = dummy_data.loc[first_index,'answer_label']
    state.question_lang_id = dummy_data.loc[first_index, 'lang_id']
    state.answer_lang_id = dummy_data.loc[first_index, 'lang_id']
    
    image_path = os.path.join('images',state.image_file)
    image = plt.imread(image_path)
    state.image = image

col1, col2 = st.beta_columns([6,4])

if col2.button('Get a random example'):
    sample = dummy_data.sample(1).reset_index()
    state.image_file = sample.loc[0,'image_file']
    state.question = sample.loc[0,'question'].strip('- ')
    state.answer_label = sample.loc[0,'answer_label']
    state.question_lang_id = sample.loc[0, 'lang_id']
    state.answer_lang_id = sample.loc[0, 'lang_id']

    image_path = os.path.join('images',state.image_file)
    image = plt.imread(image_path)
    state.image = image

col2.write("OR")

uploaded_file = col2.file_uploader('Upload your image', type=['png','jpg','jpeg'])
if uploaded_file is not None:
    state.image_file = os.path.join('images/val2014',uploaded_file.name)
    state.image = np.array(Image.open(uploaded_file))


transformed_image = get_transformed_image(state.image)

# Display Image
col1.image(state.image, use_column_width='always')

# Display Question
question = col2.text_input(label="Question", value=state.question)
col2.markdown(f"""**English Translation**: {question if state.question_lang_id == "en" else translate(question, 'en')}""")
question_inputs = get_text_attributes(question)

# Select Language
options = ['en', 'de', 'es', 'fr']
state.answer_lang_id = col2.selectbox('Answer Language', index=options.index(state.answer_lang_id), options=options, format_func = lambda x: code_to_name[x])
# Display Top-5 Predictions
with st.spinner('Loading model...'):
    model = load_model(checkpoints[0])
with st.spinner('Predicting...'):
    logits = predict(transformed_image, dict(question_inputs))
logits = softmax(logits)
labels, values = get_top_5_predictions(logits, answer_reverse_mapping)
translated_labels = translate_labels(labels, state.answer_lang_id)
fig = plotly_express_horizontal_bar_plot(values, translated_labels)
st.plotly_chart(fig, use_container_width = True)


st.write(read_markdown("abstract.md"))
st.write(read_markdown("caveats.md"))
st.write("# Methodology")
st.image("./misc/Multilingual-VQA.png", caption="Masked LM model for Image-text Pretraining.")
st.markdown(read_markdown("pretraining.md"))
st.markdown(read_markdown("finetuning.md"))
st.write(read_markdown("challenges.md"))
st.write(read_markdown("social_impact.md"))
st.write(read_markdown("references.md"))
st.write(read_markdown("checkpoints.md"))
st.write(read_markdown("acknowledgements.md"))