# Image Linear Transformation

Apply linear transformation (a * input + b) to adjust image levels, brightness, and contrast

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

- **Category:** Design

- **Keywords:** image, linear, transformation, levels, adjustment, brightness, contrast, formula

## Overview

The Image Linear Transformation tool allows you to precisely adjust image brightness, contrast, and color levels by applying the mathematical formula result = a * input + b to your image pixels.

## Inputs

- **Image File** (file): Upload any image file to apply linear transformation
- **Multiplier (a)** (text): Multiplier value (a). Can be single number for all channels or comma-separated values for each channel. Formula: result = a * input + b
- **Offset (b)** (text): Offset value (b). Can be single number for all channels or comma-separated values for each channel. Formula: result = a * input + b
- **Channel Mode** (select): Apply transformation to specific channels or all channels
- **Output Format** (select): Choose output format or keep original
- **Quality (1-100)** (number): Output quality for lossy formats

## When to use

- Correcting underexposed or overexposed photos by adjusting brightness levels.
- Enhancing image contrast to make details stand out more clearly.
- Applying specific color channel adjustments to achieve custom artistic effects.

## How it works

- Upload your image file in a supported format like JPEG, PNG, or WebP.
- Enter your multiplier (a) and offset (b) values to define the transformation intensity.
- Select the target channel mode and output format if you wish to convert the file.
- Process the image to apply the linear transformation and download the adjusted result.

## Use cases

- Standardizing brightness across a batch of images for consistent web display.
- Recovering details from dark, underexposed photographs using offset adjustments.
- Creating high-contrast stylized graphics for design projects.

## Frequently asked questions

### What does the formula a * input + b do?

The multiplier (a) scales the pixel values to adjust contrast, while the offset (b) shifts the values to adjust overall brightness.

### Can I adjust individual color channels?

Yes, you can provide comma-separated values for the multiplier and offset to target specific channels independently.

### What file formats are supported?

The tool supports JPEG, PNG, WebP, GIF, BMP, and TIFF formats for input.

### Does this tool change the file size?

Yes, especially if you choose a different output format or adjust the quality setting during the transformation.

### What is the maximum file size I can upload?

You can upload image files up to 10MB in size.

## Related tools

- [Image Affine Transformation](https://elysiatools.com/en/tools/image-affine): Apply affine transformation for scaling, rotation, shearing, and translation
- [Image Modulation](https://elysiatools.com/en/tools/image-modulate): Apply modulation transformation for brightness, saturation, and hue adjustments
- [Image Perspective Transformation](https://elysiatools.com/en/tools/image-perspective): Apply perspective transformation for 3D-like effects and perspective correction
- [Image Projective Transformation](https://elysiatools.com/en/tools/image-projective): Apply advanced projective transformation for complex 3D surface mapping and projection effects
- [Image Flip (Vertical)](https://elysiatools.com/en/tools/image-flip): Flip images vertically (top to bottom) with options for output format and quality
- [Image Flop (Horizontal)](https://elysiatools.com/en/tools/image-flop): Flop images horizontally (left to right) with options for output format and quality
- [Image Matrix Recombination](https://elysiatools.com/en/tools/image-recomb): Apply matrix recombination for advanced color space transformations and channel mixing
- [Image Composite Matrix](https://elysiatools.com/en/tools/image-composite-matrix): Apply composite transformation by combining multiple basic transformations (scaling, rotation, shearing). See how transformation matrices multiply and create complex effects.

## 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