Building Geography-Agnostic Models for Fairer Image Classification

Core Concepts

The core message of this paper is to analyze and mitigate the inherent geographical biases present in state-of-the-art image classification models, in order to make them more robust and fair across different geographical regions and income levels.

Abstract

The paper analyzes the performance of popular image recognition models like VGG and ResNet on two diverse datasets - the Dollar Street Dataset and ImageNet. It reveals a significant gap in the performance of these models on images from high-income and low-income households, as well as images from western and non-western geographies.
To address this issue, the paper explores several techniques:

Weighted Loss: Reweighting the loss function to penalize low-income images more during training, in order to improve classification of these images.

Sampling: Oversampling low-income images and undersampling high-income images to make the training data distribution more uniform across income levels.

Focal Loss: Using a focal loss function to down-weight the "easy" high-income examples and focus more on the "hard" low-income examples during training.

Adversarial Discriminative Domain Adaptation (ADDA): Leveraging domain adaptation techniques to bridge the gap between high-income and low-income image representations.

The experiments show that the focal loss approach with a gamma value of 5 performs the best on the Dollar Street dataset, while the results on ImageNet are not as promising. The ADDA experiments suggest that the domain shift between high and low-income images is too large for the model to effectively adapt. Overall, the paper highlights the need for building more geography-agnostic and fair image recognition models.

Stats

The paper uses the following key statistics and figures:

The Dollar Street Dataset contains ~30,000 images from 264 homes in 50 countries, belonging to 131 classes.
The ImageNet dataset used in the experiments contains 50,249 images from 596 classes, with location metadata obtained from the Flickr API.
The GDP per capita (nominal) values used to map the ImageNet images to income levels are: Oceania ($53,220), North America ($49,240), Europe ($29,410), South America ($8,560), Asia ($7,350), and Africa ($1,930).

Quotes

"Recent advancements in GPUs and ASICs like TPU, resulting in increased computational power, have led to many object recognition systems achieving state of the art performance on publicly available datasets like ImageNet [8], COCO [15], and OpenImages [12]. However, these systems seem to be biased toward images obtained from well-developed western countries, partly because of the skewed distribution of the geographical source location of such images [7]."
"DeVries et al [7] revealed a major gap in the top-5 average accuracy of six object recognition systems on images from high and low income households and images from western and non-western geographies. Our goal is to reduce this bias introduced into the systems because of the inherent nature of the training data."

Key Insights Distilled From

Classification for everyone

by Akshat Jinda... at arxiv.org 04-03-2024

https://arxiv.org/pdf/2312.02957.pdf

Deeper Inquiries

How can we further improve the performance of geography-agnostic models on datasets like ImageNet, where the domain shift between high and low-income images is more pronounced

To further enhance the performance of geography-agnostic models on datasets like ImageNet, where the domain shift between high and low-income images is more pronounced, several strategies can be implemented:

Fine-tuning with Transfer Learning: Utilize transfer learning techniques by fine-tuning the pre-trained models on a more diverse dataset that includes a balanced representation of high and low-income images. This can help the model adapt better to the domain shift.

Data Augmentation: Implement data augmentation techniques specifically tailored to address the geographical biases present in the dataset. This can involve synthesizing images from underrepresented regions or income levels to create a more balanced training set.

Domain Adaptation Methods: Explore advanced domain adaptation methods beyond ADDA, such as CycleGANs or other generative adversarial networks (GANs) that can help in aligning the feature distributions between different geographical regions or income levels.

Ensemble Learning: Combine predictions from multiple models trained on different subsets of the data to create a more robust and accurate prediction. This can help mitigate biases present in individual models.

Bias Detection and Mitigation: Implement techniques to detect and mitigate biases in the dataset that may affect model performance. This can involve preprocessing steps to balance the representation of different geographical regions or income levels in the training data.

By incorporating these strategies, the geography-agnostic models can be further optimized to perform effectively across diverse geographical and income contexts.

What other techniques, beyond the ones explored in this paper, can be used to make image recognition models more robust to geographical biases

Beyond the techniques explored in the paper, additional methods can be employed to enhance the robustness of image recognition models to geographical biases:

Geographical Data Augmentation: Generate synthetic images representing underrepresented geographical regions or income levels to augment the training data. This can help in creating a more balanced dataset and improving model generalization.

Geographical Feature Engineering: Integrate geographical features such as latitude, longitude, or region-specific attributes into the model architecture. By incorporating these features, the model can learn to adapt its predictions based on the geographical context of the images.

Geographical Adversarial Training: Implement adversarial training techniques that specifically focus on aligning the feature representations of images from different geographical regions. This can help in reducing the impact of geographical biases on model predictions.

Geographical Clustering: Group images based on geographical similarities and train the model on these clustered subsets. By focusing on specific geographical clusters during training, the model can learn region-specific patterns and improve performance on diverse datasets.

Geographical Calibration: Develop calibration methods that adjust the model predictions based on the geographical context of the input images. This can help in fine-tuning the model to make more accurate predictions across different geographical regions.

By incorporating these additional techniques, image recognition models can become more resilient to geographical biases and perform effectively across diverse datasets.

How can the insights from this work be extended to other domains beyond image classification, where geographical and demographic biases may be present in the data and models

The insights gained from this work on mitigating geographical biases in image recognition models can be extended to various other domains beyond image classification where similar biases may exist. Some ways to apply these insights include:

Natural Language Processing (NLP): In NLP tasks such as sentiment analysis or language translation, models can be trained to account for regional or demographic variations in language usage. Techniques like domain adaptation can help in adapting models to different linguistic contexts.

Healthcare: In healthcare applications, models can be tailored to address demographic biases in medical data. By considering factors like geographical location or socioeconomic status, healthcare AI systems can provide more personalized and equitable care recommendations.

Finance and Economics: Models in finance and economics can benefit from addressing geographical biases in datasets. By incorporating insights from this work, predictive models can be optimized to make more accurate forecasts across diverse regions and income levels.

Social Sciences: Applications in social sciences, such as demographic studies or urban planning, can leverage techniques to mitigate biases related to geographical representation in data. This can lead to more comprehensive and unbiased analyses in these fields.

By applying the principles of mitigating geographical biases learned from image classification to these diverse domains, AI systems can be developed to be more inclusive, fair, and effective in their decision-making processes.