apps/mlm.py

from .utils import (
    get_text_attributes,
    get_top_5_predictions,
    get_transformed_image,
    plotly_express_horizontal_bar_plot,
    bert_tokenizer,
)

import streamlit as st
import numpy as np
import pandas as pd
import os
import matplotlib.pyplot as plt
from mtranslate import translate
from .utils import read_markdown
import requests
from PIL import Image
from .model.flax_clip_vision_bert.modeling_clip_vision_bert import (
    FlaxCLIPVisionBertForMaskedLM,
)


def softmax(logits):
    return np.exp(logits) / np.sum(np.exp(logits), axis=0)

def app(state):
    mlm_state = state

    with st.beta_expander("Usage"):
        st.write(read_markdown("mlm_usage.md"))
    st.write(read_markdown("mlm_intro.md"))

    # @st.cache(persist=False) # TODO: Make this work with mlm_state. Currently not supported.
    def predict(transformed_image, caption_inputs):
        outputs = mlm_state.mlm_model(pixel_values=transformed_image, **caption_inputs)
        indices = np.where(caption_inputs["input_ids"] == bert_tokenizer.mask_token_id)[1][0]
        preds = outputs.logits[0][indices]
        scores = np.array(preds)
        return scores

    # @st.cache(persist=False)
    def load_model(ckpt):
        return FlaxCLIPVisionBertForMaskedLM.from_pretrained(ckpt)

    mlm_checkpoints = ["flax-community/clip-vision-bert-cc12m-70k"]
    dummy_data = pd.read_csv("cc12m_data/vqa_val.tsv", sep="\t")

    first_index = 15
    # Init Session mlm_state
    if mlm_state.mlm_image_file is None:
        mlm_state.mlm_image_file = dummy_data.loc[first_index, "image_file"]
        caption = dummy_data.loc[first_index, "caption"].strip("- ")
        mlm_state.unmasked_caption = caption
        ids = bert_tokenizer.encode(caption)
        mask_index = np.random.randint(1, len(ids) - 1)
        mlm_state.currently_masked_token = ids[mask_index]
        ids[mask_index] = bert_tokenizer.mask_token_id
        mlm_state.caption = bert_tokenizer.decode(ids[1:-1])
        mlm_state.caption_lang_id = dummy_data.loc[first_index, "lang_id"]

        image_path = os.path.join("cc12m_data/resized_images_vqa", mlm_state.mlm_image_file)
        image = plt.imread(image_path)
        mlm_state.mlm_image = image

    if mlm_state.mlm_model is None:
        # Display Top-5 Predictions
        with st.spinner("Loading model..."):
            mlm_state.mlm_model = load_model(mlm_checkpoints[0])

    query1 = st.text_input(
        "Enter a URL to an image",
        value="http://images.cocodataset.org/val2017/000000039769.jpg",
    )

    col1, col2, col3 = st.beta_columns([2,1, 2])
    if col1.button(
        "Get a random example",
        help="Get a random example from the 100 `seeded` image-text pairs.",
    ):
        sample = dummy_data.sample(1).reset_index()
        mlm_state.mlm_image_file = sample.loc[0, "image_file"]
        caption = sample.loc[0, "caption"].strip("- ")
        mlm_state.unmasked_caption = caption
        ids = bert_tokenizer.encode(caption)
        mask_index = np.random.randint(1, len(ids) - 1)
        mlm_state.currently_masked_token = ids[mask_index]
        ids[mask_index] = bert_tokenizer.mask_token_id
        mlm_state.caption = bert_tokenizer.decode(ids[1:-1])
        mlm_state.caption_lang_id = sample.loc[0, "lang_id"]

        image_path = os.path.join("cc12m_data/resized_images_vqa", mlm_state.mlm_image_file)
        image = plt.imread(image_path)
        mlm_state.mlm_image = image

    col2.write("OR")

    if col3.button("Use above URL"):
        image_data = requests.get(query1, stream=True).raw
        image = np.asarray(Image.open(image_data))
        mlm_state.mlm_image = image



    transformed_image = get_transformed_image(mlm_state.mlm_image)

    new_col1, new_col2 = st.beta_columns([5, 5])

    # Display Image
    new_col1.image(mlm_state.mlm_image, use_column_width="auto")

    # Display caption
    new_col2.write("Write your text with exactly one [MASK] token.")
    mlm_state.caption = new_col2.text_input(
        label="Text",
        value=mlm_state.caption,
        help="Type your masked caption regarding the image above in one of the four languages.",
    )

    if mlm_state.unmasked_caption == mlm_state.caption.replace("[MASK]", mlm_state.currently_masked_token):
        new_col2.markdown("**Masked Token**: "+mlm_state.currently_masked_token)
        new_col2.markdown("**English Translation: " + mlm_state.unmasked_caption if mlm_state.caption_lang_id == "en" else translate(mlm_state.unmasked_caption, 'en'))

    else:
        new_col2.markdown(
            f"""**English Translation**: {mlm_state.caption if mlm_state.caption_lang_id == "en" else translate(mlm_state.caption, 'en')}"""
        )
    caption_inputs = get_text_attributes(mlm_state.caption)

    # Display Top-5 Predictions
    with st.spinner("Predicting..."):
        scores = predict(transformed_image, dict(caption_inputs))
    scores = softmax(scores)
    labels, values = get_top_5_predictions(scores)
    filled_sentence = mlm_state.caption.replace("[MASK]", labels[0])
    st.write("Filled Sentence: " + filled_sentence)
    st.write( f"""**English Translation**: {translate(filled_sentence, 'en')}""")
    # newer_col1, newer_col2 = st.beta_columns([6,4])
    fig = plotly_express_horizontal_bar_plot(values, labels)
    st.dataframe(pd.DataFrame({"Tokens":labels, "English Translation": list(map(lambda x: translate(x),labels))}).T)
    st.plotly_chart(fig, use_container_width=True)