Tag Archives: Pictures

Addressing Fairness and Explainability in Image Classification Using Optimal Transport

Our new paper, with François Hu and Philipp Ratz, Addressing Fairness and Explainability in Image Classification Using Optimal Transport, is now available on ArXiv.

Algorithmic Fairness and the explainability of potentially unfair outcomes are crucial for establishing trust and accountability of Artificial Intelligence systems in domains such as healthcare and policing. Though significant advances have been made in each of the fields separately, achieving explainability in fairness applications remains challenging, particularly so in domains where deep neural networks are used. At the same time, ethical data-mining has become ever more relevant, as it has been shown countless times that fairness-unaware algorithms result in biased outcomes. Current approaches focus on mitigating biases in the outcomes of the model, but few attempts have been made to try to explain why a model is biased. To bridge this gap, we propose a comprehensive approach that leverages optimal transport theory to uncover the causes and implications of biased regions in images, which easily extends to tabular data as well. Through the use of Wasserstein barycenters, we obtain scores that are independent of a sensitive variable but keep their marginal orderings. This step ensures predictive accuracy but also helps us to recover the regions most associated with the generation of the biases. Our findings hold significant implications for the development of trustworthy and unbiased AI systems, fostering transparency, accountability, and fairness in critical decision-making scenarios across diverse domains.

Sharing pictures from holidays in the Canadian Rockies (with R)

My kids have a very popular blog (at least among their grandmothers) where they frequently post pictures from everyday’s life (since they live 5000km from them), as well as pictures taken from holidays. This afternoon, I tried to used the popupImage function from the leaflet package to post pictures, on a map (to explain where we spent our holiday this summer). This post is just to keep tracks of that code.

First, we need to load the appropriate R packages

library(leaflet)
library(mapview)

Then, we take a picture, and we locate it, for instance Mirror Lake (on the trail to Lake Agnes). Since leaflet uses openstreetmap, I recommend to use it also for location (and not google maps… coordinates can be slightly different)

df=data.frame(lat =51.41603, long=-116.23946,
nom = "Miror Lake",photo="http://freakonometrics.free.fr/jaspeR/_DSC5967.jpg")

I guess you can also use the metadata if you take pictures with a cell phone, and you add the location… but I am (very) old fashioned, and still use a camera to take pictures. Then you can add a dozen pictures

df=rbind(df, data.frame(lat =51.4164, long=-116.2442,
nom = "Lake Agnes",photo="http://freakonometrics.free.fr/jaspeR/_DSC6003.jpg"))
df=rbind(df, data.frame(lat =51.3215642,long=-116.193718,
nom="Moraine Lake",photo="http://freakonometrics.free.fr/jaspeR/_DSC5957.jpg"))

From that dataframe, we need two kinds of information: the location, and the url of the picture,

data_df=df[,c("lat","long")]
images = as.character(df$photo)

Then we can create the leaflet map (sorry for typos, but wordpress converts the > symbol into some “>” characters… which makes R pipe operator hard to read)

m = leaflet(data_df) %>%
  addTiles() %>%
  addCircleMarkers(
    fillOpacity = 0.8, radius = 5,
    lng = ~long, lat =~lat, 
    popup = popupImage(images)
  )

and export it (in a nice html file)

library(htmlwidgets)
saveWidget(m, file="jaspR.html")

Insurance data science : Pictures

At the Summer School of the Swiss Association of Actuaries, in Lausanne, following the part of Jean-Philippe Boucher (UQAM) on telematic data, I will start talking about pictures this Wednesday. Slides are available online

Ewen Gallic (AMSE) will present a tutorial on satellite pictures, and a simple classification problem, related to Alzeimher detection.

We will try to identify what is on the following pictures, starting with the car

(we will see that the car is indeed identified)

We will also discuss previous pictures from the summer school