Understanding Brightness and Contrast

Brightness and contrast adjustments are fundamental image editing operations that can dramatically improve photo quality, correct exposure issues, and enhance visual appeal for both digital and print media.

Step-by-Step Instructions

Upload your image using the file input or drag and drop
Adjust the brightness slider to make the image lighter or darker
Modify the contrast slider to increase or decrease the difference between light and dark areas
Use the reset button to return to original settings
Download your edited image when satisfied with the results

Practical Examples

Correcting Underexposed Photos

Increase brightness by 20-40% and contrast by 10-20% to salvage dark photos taken in low light conditions.

Enhancing Product Images

Apply +15% brightness and +25% contrast to make product images pop against white backgrounds for e-commerce.

Social Media Optimization

Use +10% brightness and +15% contrast to ensure images stand out on social media feeds with varied display conditions.

Reference Values

Use Case	Brightness Range	Contrast Range
Portrait Enhancement	+5% to +15%	+10% to +20%
Low Light Correction	+20% to +40%	+15% to +25%
Overexposure Fix	-10% to -25%	+5% to +15%

Frequently Asked Questions

Which browsers support this tool?

All modern browsers with Canvas support including Chrome, Firefox, Safari, and Edge. Mobile browsers on iOS and Android are fully supported.

Are there any file size limitations?

For performance reasons, images larger than 10MP are automatically downscaled for preview. Full resolution processing occurs only during export.

How are brightness and contrast calculated?

Brightness uses additive adjustment while contrast applies multiplicative scaling. Both operations use linear color space calculations for accurate results.

Does this tool preserve image metadata?

EXIF data and other metadata are preserved during processing. No personal information is removed or modified.

What export formats are available?

PNG for lossless quality, JPEG for smaller file sizes with configurable quality, and WebP when supported by your browser.

Formulas and Assumptions

Brightness Calculation

pixel = pixel × (1 + brightness/100)

Where brightness ranges from -100 to +100

Contrast Calculation

pixel = (pixel - 0.5) × (1 + contrast/100) + 0.5

Where contrast ranges from -100 to +100

Color Space

sRGB color space with gamma correction

Gamma value: 2.2

Precision

8-bit per channel precision

Values clamped to 0-255 range

Brightness and Contrast Adjuster

Image Information

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Brightness and Contrast Adjuster

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