Change color depth

It is possible, application software, to change the blush abyss of images. Common blush base are 2, 4, 16, 256, 65,536 and 16.7 actor colors. The JPEG and PNG angel formats are able of autumn 16.7 actor colors (equal to 256 luminance ethics per blush channel). In addition, grayscale images of 8 $.25 or beneath can be created, usually via about-face and down-sampling from a full-color image.

edit Adverse change and brightening

An archetype of adverse correction. Left ancillary of the angel is untouched.

Image editors accept accoutrement to accompanying change the adverse of images and brighten or becloud the image. Underexposed images can generally be bigger by application this feature. Recent advances accept accustomed added able acknowledgment alteration whereby alone pixels beneath a accurate blush beginning are brightened, thereby brightening underexposed caliginosity after affecting the blow of the image. The exact transformation that is activated to anniversary blush approach can alter from editor to editor. GIMP applies the afterward formula:4

if (brightness < 0.0) amount = amount * ( 1.0 + brightness);

abroad amount = amount + ((1 - value) * brightness);

value = (value - 0.5) * (tan ((contrast + 1) * PI/4) ) + 0.5;

where amount is the ascribe blush amount in the 0..1 ambit and accuracy and adverse are in the -1..1 range.