Brightness Adjustment
The process of uniformly increasing or decreasing the luminance of all pixels in an image to correct overall lightness.
Brightness adjustment uniformly increases or decreases the luminance values of all pixels in an image. It is used to brighten photos taken in dim environments or tone down overexposed images.
Simple brightness adjustment adds or subtracts the same value from every pixel. Increasing too much causes highlight clipping (values capped at 255), while decreasing too much causes shadow crushing (values floored at 0). For more natural corrections, use tone curves or reference the histogram while adjusting.
Brightness adjustment is often confused with exposure correction. Exposure refers to the amount of light captured by the sensor during shooting, while brightness adjustment is a post-capture digital process. Backlit photos can be improved with brightness adjustment, but clipped highlights cannot be recovered.