What is multimodal sentiment analysis?

Analyzing and comprehending sentiment (emotions or views) presented in many modalities or forms of data, such as text, images, audio, and video, is called multimodal sentiment analysis. Traditional sentiment analysis frequently focuses on text data, but with the rising prominence of multimedia content on the internet and social media, there is an increasing need to comprehend sentiment across several modalities. Multimodal sentiment analysis is useful in real-world applications such as social media monitoring, customer feedback analysis, product ratings, and market research because it provides useful insights across several modalities.

Note: Refer to this Answer for a detailed exploration of modalities.

An illustration of conveying opinions using a multimodal communication channel
An illustration of conveying opinions using a multimodal communication channel

How does it work?

The multimodal sentiment analysis process encompasses several stages, from data collection to model deployment. The stages are as follows:

  • Data collection: In this stage, we collect data in several modalities, including text, images, audio, and video. This data may originate from various sources, such as social media, customer reviews, or any other medium where individuals share their opinions.

  • Data preprocessing: For every modality, we clean up and prepare the data. This might include audio feature extraction, video frame sampling, image scaling, and text tokenization.

  • Modality-specific analysis: Next, determine each modality using the following specific methods:

    • Text analysis: Extract sentiment-bearing information from the text using natural language processing (NLP) methods.

    • Image analysis: Identify facial expressions, objects, scenes, and other visual signals that convey sentiment using computer vision algorithms.

    • Audio analysis: Extract speech, tone, pitch, and acoustic features that convey sentiment from audio data.

    • Video analysis: Combine image and audio analysis to incorporate data from both visual and audible modalities.

  • Feature extraction: From each modality, we extract the most important characteristics. These characteristics are the essential components that contribute to sentiment among several modalities.

  • Multimodal fusion: Fused representations are produced by combining features across multiple modalities. Early fusion (combining characteristics at the input level) and late fusion (combining features at a higher level) are two examples of fusion.

Note: Review this Answer for a detailed look into multimodal fusion.

Workflow mechanism of multimodal sentimental analysis
Workflow mechanism of multimodal sentimental analysis
  • Sentiment prediction model: Next, utilize the fused features to train a machine learning model for sentiment prediction. This model might be built using ensemble techniques, traditional classifiers, or deep learning models (such as neural networks).

  • Evaluation: We also use relevant measures to assess the multimodal sentiment analysis model’s success, including accuracy, precision, recall, F1 score, or AUC-ROC. This stage ensures that the model generalizes adequately to new, unseen data.

  • Deployment: In this stage, we use the trained model to analyze sentiment in newly collected information by deploying it in a real-world application or system.

  • User interface or application integration: Provide end users with the ability to engage with and analyze the sentiment analysis output by incorporating the results into an intuitive interface or application. This is an important step for real-world applications where users must decide based on sentiment information.

  • Continuous monitoring and improvement: Keep track of the model’s performance periodically. As user behavior, data distribution, or other pertinent aspects change, the model should be updated accordingly. The model’s effectiveness in gathering sentiment across many modalities is ensured by continuous improvement.

Note: The effectiveness of multimodal sentiment analysis depends on properly integrating information from many sources, allowing for a more thorough understanding of user sentiments conveyed differently.

Example

The following code performs multimodal sentiment analysis by combining sentiment analysis on a given text with a simplistic sentiment analysis on a randomly generated image, yielding an overall sentiment prediction:

import nltk
from nltk.sentiment import SentimentIntensityAnalyzer
import cv2
import os
import numpy as np
import matplotlib.pyplot as plt
nltk.download('vader_lexicon', quiet=True)
sia = SentimentIntensityAnalyzer()
def analyze_text_sentiment(text):
sentiment_score = sia.polarity_scores(text)['compound']
return 'positive' if sentiment_score >= 0 else 'negative'
def generate_random_image():
random_image = np.random.randint(0, 256, size=(3, 3, 3), dtype=np.uint8)
cv2.imwrite("random_image.jpg", random_image)
return "random_image.jpg"
def analyze_image_sentiment(image_path):
image = cv2.imread(image_path)
is_grayscale = cv2.cvtColor(image, cv2.COLOR_BGR2GRAY)
return 'positive' if is_grayscale.all() else 'negative'
def multimodal_sentiment_analysis(text):
text_sentiment = analyze_text_sentiment(text)
random_image_path = generate_random_image()
image_sentiment = analyze_image_sentiment(random_image_path)
# Display text and image
print(f"Text: {text}\n")
img = cv2.imread(random_image_path)
plt.imshow(cv2.cvtColor(img, cv2.COLOR_BGR2RGB))
plt.axis('off')
plt.savefig("output/MSA.png", dpi=300)
# Combine modalities and make a final sentiment prediction
if text_sentiment == 'positive' and image_sentiment == 'positive':
result = 'Overall sentiment: Positive'
else:
result = 'Overall sentiment: Negative'
# Clean up
os.remove(random_image_path)
return result
text_example = "I love this product! It works great."
result = multimodal_sentiment_analysis(text_example)
print(result)

Explanation

Here is the breakdown of the above code:

  • Lines 1–6: We import the necessary libraries.

  • Line 8: We download the VADER lexicon data needed for sentiment analysis using the SentimentIntensityAnalyzer.

  • Line 9: We create an instance of the SentimentIntensityAnalyzer class, denoted as sia, which will be used for text sentiment analysis.

  • Lines 11–13: The analyze_text_sentiment method takes a text input, analyzes its sentiment using the VADER sentiment analyzer, and returns a sentiment label ('positive' or 'negative') based on the compound score.

  • Lines 15–18: The generate_random_image method creates a random 3x3 image with random pixel values and saves it to a file named "random_image.jpg".

  • Lines 20–23: The analyze_image_sentiment method loads the image created in the previous step and performs a simple image analysis by checking if the image is gray scale.

  • Lines 25–41: The multimodal_sentiment_analysis function combines text and image modalities to make a final sentiment prediction.

    • It first analyzes the sentiment of the input text using analyze_text_sentiment.

    • It generates a random image and analyzes its sentiment using analyze_image_sentiment.

    • It cleans up the temporary random image file created during the analysis. It removes the file using the os.remove function to ensure proper resource management.

    • The overall sentiment prediction is based on both text and image sentiments. If both are positive, the result is 'Overall sentiment: Positive'; otherwise, it is 'Overall sentiment: Negative'.

  • Line 47: An example text, "I love this product! It works great", is used to demonstrate the multimodal sentiment analysis.

  • Line 49: The result is printed based on the combined sentiment analysis of text and a randomly generated image.

Advantages

Multimodal sentiment analysis has various advantages over unimodal (single modality) sentiment analysis. The following are some significant benefits:

  • A richer understanding of user sentiment

  • Improved accuracy and robustness

  • Handling ambiguity and context

  • Increased relevance in the multimedia environment

  • Enhanced user experience

  • Support for multilingual analysis

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