Below are the abstract, introduction, and conclusion of a computer science research paper. Please summarize the main contribution of the work in a single sentence. Your response should include the summary and no additional text.

Paper text:

As machine learning methods see greater adoption and implementation in high stakes applications such
as medical image diagnosis, the need for model interpretability and explanation has become more
critical.
Classical approaches that assess feature importance (eg saliency maps) do not explain how and why a particular region of an image is relevant to the prediction.
We propose
a method that explains the outcome of a classification black-box by gradually exaggerating
the semantic effect of a given class.
Given a query input to a classifier, our method produces a
progressive set of plausible variations of that query, which gradually change the posterior probability
from its original class to its negation.
These counter-factually generated samples preserve features
unrelated to the classification decision, such that a user can employ our method as a ``tuning knob'' to traverse a data manifold while crossing the decision boundary.  
Our method is model agnostic and only requires the output value and gradient of the predictor with respect to its input.
A method to explain a classifier, by generating visual perturbation of an image by exaggerating  or diminishing the semantic features that the classifier associates with a target label.