Search Results for author: Alexander Hepburn

Found 15 papers, 2 papers with code

An Interactive Human-Machine Learning Interface for Collecting and Learning from Complex Annotations

1 code implementation28 Mar 2024 Jonathan Erskine, Matt Clifford, Alexander Hepburn, Raúl Santos-Rodríguez

Human-Computer Interaction has been shown to lead to improvements in machine learning systems by boosting model performance, accelerating learning and building user confidence.

Binary Classification counterfactual

Evaluating Perceptual Distances by Fitting Binomial Distributions to Two-Alternative Forced Choice Data

no code implementations15 Mar 2024 Alexander Hepburn, Raul Santos-Rodriguez, Javier Portilla

The two-alternative forced choice (2AFC) experimental setup is popular in the visual perception literature, where practitioners aim to understand how human observers perceive distances within triplets that consist of a reference image and two distorted versions of that image.

Decision Making Perceptual Distance

Data is Overrated: Perceptual Metrics Can Lead Learning in the Absence of Training Data

no code implementations6 Dec 2023 Tashi Namgyal, Alexander Hepburn, Raul Santos-Rodriguez, Valero Laparra, Jesus Malo

Perceptual metrics are traditionally used to evaluate the quality of natural signals, such as images and audio.

What You Hear Is What You See: Audio Quality Metrics From Image Quality Metrics

no code implementations19 May 2023 Tashi Namgyal, Alexander Hepburn, Raul Santos-Rodriguez, Valero Laparra, Jesus Malo

In this study, we investigate the feasibility of utilizing state-of-the-art image perceptual metrics for evaluating audio signals by representing them as spectrograms.

Disentangling the Link Between Image Statistics and Human Perception

no code implementations17 Mar 2023 Alexander Hepburn, Valero Laparra, Raúl Santos-Rodriguez, Jesús Malo

Moreover, the direct evaluation of the hypothesis was limited by the inability of the classical image models to deliver accurate estimates of the probability.

Denoising

Identification, explanation and clinical evaluation of hospital patient subtypes

no code implementations19 Jan 2023 Enrico Werner, Jeffrey N. Clark, Ranjeet S. Bhamber, Michael Ambler, Christopher P. Bourdeaux, Alexander Hepburn, Christopher J. McWilliams, Raul Santos-Rodriguez

We present a pipeline in which unsupervised machine learning techniques are used to automatically identify subtypes of hospital patients admitted between 2017 and 2021 in a large UK teaching hospital.

Clinical Knowledge

What and How of Machine Learning Transparency: Building Bespoke Explainability Tools with Interoperable Algorithmic Components

no code implementations8 Sep 2022 Kacper Sokol, Alexander Hepburn, Raul Santos-Rodriguez, Peter Flach

Explainability techniques for data-driven predictive models based on artificial intelligence and machine learning algorithms allow us to better understand the operation of such systems and help to hold them accountable.

Explanation Generation

Sampling Based On Natural Image Statistics Improves Local Surrogate Explainers

no code implementations8 Aug 2022 Ricardo Kleinlein, Alexander Hepburn, Raúl Santos-Rodríguez, Fernando Fernández-Martínez

By training a simple, more interpretable model to locally approximate the decision boundary of a non-interpretable system, we can estimate the relative importance of the input features on the prediction.

Orthonormal Convolutions for the Rotation Based Iterative Gaussianization

no code implementations8 Jun 2022 Valero Laparra, Alexander Hepburn, J. Emmanuel Johnson, Jesús Malo

Here we present the \emph{Convolutional RBIG}: an extension that alleviates this issue by imposing that the rotation in RBIG is a convolution.

Texture Synthesis

On the relation between statistical learning and perceptual distances

no code implementations ICLR 2022 Alexander Hepburn, Valero Laparra, Raul Santos-Rodriguez, Johannes Ballé, Jesús Malo

Since machine learning relies on the statistics of training data as well, the above connection has interesting implications when using perceptual distances (which mimic the behavior of the human visual system) as a loss function.

BIG-bench Machine Learning Perceptual Distance +1

Explainers in the Wild: Making Surrogate Explainers Robust to Distortions through Perception

no code implementations22 Feb 2021 Alexander Hepburn, Raul Santos-Rodriguez

We generate explanations for images in the Imagenet-C dataset and demonstrate how using a perceptual distances in the surrogate explainer creates more coherent explanations for the distorted and reference images.

Image Classification

bLIMEy: Surrogate Prediction Explanations Beyond LIME

1 code implementation29 Oct 2019 Kacper Sokol, Alexander Hepburn, Raul Santos-Rodriguez, Peter Flach

Surrogate explainers of black-box machine learning predictions are of paramount importance in the field of eXplainable Artificial Intelligence since they can be applied to any type of data (images, text and tabular), are model-agnostic and are post-hoc (i. e., can be retrofitted).

Explainable artificial intelligence

PerceptNet: A Human Visual System Inspired Neural Network for Estimating Perceptual Distance

no code implementations28 Oct 2019 Alexander Hepburn, Valero Laparra, Jesús Malo, Ryan McConville, Raul Santos-Rodriguez

Traditionally, the vision community has devised algorithms to estimate the distance between an original image and images that have been subject to perturbations.

Perceptual Distance

Enforcing Perceptual Consistency on Generative Adversarial Networks by Using the Normalised Laplacian Pyramid Distance

no code implementations9 Aug 2019 Alexander Hepburn, Valero Laparra, Ryan McConville, Raul Santos-Rodriguez

While an important part of the evaluation of the generated images usually involves visual inspection, the inclusion of human perception as a factor in the training process is often overlooked.

Image Segmentation Image-to-Image Translation +2

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