# Contrast Enhancement Estimation for Digital Image Forensics

## TL;DR

This paper introduces a robust method for estimating contrast enhancement in digital images, enabling forgery detection and localization even under noisy conditions, with extensive experimental validation.

## Contribution

The paper presents a novel iterative algorithm to estimate contrast enhancement and original histograms from a single noisy image, improving robustness over previous methods.

## Key findings

- Effective contrast enhancement estimation under noise
- Ability to detect and localize contrast-enhanced regions
- Demonstrated high accuracy and efficiency in experiments

## Abstract

Inconsistency in contrast enhancement can be used to expose image forgeries. In this work, we describe a new method to estimate contrast enhancement from a single image. Our method takes advantage of the nature of contrast enhancement as a mapping between pixel values, and the distinct characteristics it introduces to the image pixel histogram. Our method recovers the original pixel histogram and the contrast enhancement simultaneously from a single image with an iterative algorithm. Unlike previous methods, our method is robust in the presence of additive noise perturbations that are used to hide the traces of contrast enhancement. Furthermore, we also develop an e effective method to to detect image regions undergone contrast enhancement transformations that are different from the rest of the image, and use this method to detect composite images. We perform extensive experimental evaluations to demonstrate the efficacy and efficiency of our method method.