# Image Normalise

Normalise image histogram to enhance contrast by stretching the intensity range (British spelling)

> Canonical page: https://elysiatools.com/en/tools/image-normalise

- **Category:** Design

- **Keywords:** image, normalise, histogram, contrast, enhance, stretch, intensity, equalization, british

## Overview

Image Normalise is a professional utility designed to enhance image contrast by stretching the intensity range of your image histogram. By remapping pixel values, this tool helps reveal hidden details in shadows and highlights, ensuring your visuals appear balanced and vibrant.

## Inputs

- **Image File** (file): Upload any image file (JPEG, PNG, WebP, GIF, BMP, TIFF) to enhance contrast through histogram normalisation
- **Auto Contrast** (checkbox): Automatically enhance contrast using 1% and 99% percentiles (recommended for most images)
- **Lower Percentile** (range): Percentage of darkest pixels to ignore (0.1% - 10%). Lower values preserve more shadow detail
- **Upper Percentile** (range): Percentage of brightest pixels to ignore (90% - 99.9%). Higher values preserve more highlight detail
- **Output Format** (select): Choose output format or keep original. PNG recommended for maximum quality
- **Quality (1-100)** (number): Output quality for lossy formats (JPEG, WebP). Higher = better quality but larger file size

## When to use

- When an image appears washed out or lacks sufficient contrast.
- When you need to recover detail from underexposed or overexposed photos.
- When preparing images for print or digital display that require standardized intensity levels.

## How it works

- Upload your image file (JPEG, PNG, WebP, GIF, BMP, or TIFF).
- Enable Auto Contrast for a quick, balanced enhancement, or manually adjust the lower and upper percentiles to target specific shadow and highlight ranges.
- Select your preferred output format and quality settings.
- Process the file to download your contrast-enhanced image.

## Use cases

- Restoring clarity to scanned documents or faded historical photographs.
- Improving the visual impact of product photography for e-commerce listings.
- Standardizing image intensity across a batch of photos for consistent presentation.

## Frequently asked questions

### What does histogram normalisation do?

It stretches the range of intensity values in an image so that the darkest pixels become black and the brightest pixels become white, effectively increasing the overall contrast.

### Should I use Auto Contrast?

Yes, Auto Contrast is recommended for most images as it automatically calculates the optimal 1% and 99% percentiles to improve clarity without clipping important details.

### How do the percentile sliders affect my image?

The lower percentile ignores a percentage of the darkest pixels to preserve shadow detail, while the upper percentile ignores a percentage of the brightest pixels to protect highlight detail.

### Which output format should I choose?

PNG is recommended for maximum quality, while JPEG or WebP are better if you need to balance file size with visual fidelity.

### Is there a file size limit?

Yes, the tool supports files up to 20MB.

## Related tools

- [Image Normalize](https://elysiatools.com/en/tools/image-normalize): Normalize image histogram to enhance contrast by stretching the intensity range
- [Image Overlay Blend](https://elysiatools.com/en/tools/image-overlay): Apply overlay blend mode between two images to enhance contrast and create dramatic effects
- [Image Transpose](https://elysiatools.com/en/tools/image-transpose): Transpose images by flipping vertically then horizontally (across the main diagonal from top-left to bottom-right)
- [Image Transverse](https://elysiatools.com/en/tools/image-transverse): Transverse images by flipping horizontally then vertically (across the secondary diagonal from top-right to bottom-left)
- [Add Glow Effect](https://elysiatools.com/en/tools/image-add-glow): Add beautiful glow effects to images with customizable color, intensity, size, and style variations
- [Add Noise Effect](https://elysiatools.com/en/tools/image-add-noise): Add various types of noise effects to images with customizable intensity and parameters
- [Add Shadow Effect](https://elysiatools.com/en/tools/image-add-shadow): Add realistic shadow effects to images with customizable direction, blur, color, and intensity
- [Add Texture Effect](https://elysiatools.com/en/tools/image-add-texture): Add various texture overlays to images with customizable blend modes and intensity

## Samples

- [Web Image Processing Python Samples](https://elysiatools.com/en/samples/web-image-processing-python): Web Python image processing examples using PIL/Pillow including reading, saving, resizing, and format conversion
- [Web Image Processing TypeScript Samples](https://elysiatools.com/en/samples/web-image-processing-typescript): Web TypeScript image processing examples including image read/save, scaling, and format conversion
- [Android Image Processing Java Samples](https://elysiatools.com/en/samples/android-image-processing-java): Android Java image processing examples including reading/saving images, scaling, and format conversion
- [Android Image Processing Kotlin Samples](https://elysiatools.com/en/samples/android-image-processing-kotlin): Android Kotlin image processing examples including reading/saving images, scaling, and format conversion