Image Adjustments

With Image-Adjustments commands it is possible to correct your photos automatically or manually

Auto White Balance Auto White Balance command automatically adjusts the black point and white point in an image.
Auto Contrast Auto Contrast command adjusts the overall contrast and mixture of colors of RGB image automatically.
Auto Color Auto Color command adjusts the contrast and color of an image by identifying shadows, midtones, and highlights of an actual image.
Auto Enhance Colors Auto Enhance Colors' filter runs an automatic saturation stretch for the image on three channels.
Levels Levels command let the user correct the tonal range and color balance of an image by adjusting intensity levels of shadows, midtones, and highlights of an image.

Brightness / Contrast

 Brightness/Contrast command let the user make simple adjustments to the tonal range of an image.
Gamma Gamma command provides the ability to edit the gamma values of an image.
Hue Saturation Hue/Saturation command let the user adjust hue, saturation, and brightness of a specific color component in image or simultaneously adjust all the colors in it.
Desaturate Desaturate command converts a color image to a grayscale image in the same color mode.
Channel Mixer Channel Mixer modifies a targeted (output) color channel using a mixture of the existing (source) color channels of the image.
Posterize Posterize command let the user specify the number of tonal levels (or brightness values) for each channel in image.
Invert Invert command inverts the colors of image.
Invert Luma Invert Luma command inverts the luma of image.
Histogram Equalization Histogram Equalization command redistributes the brightness values of the pixels in an image so that they more evenly represent the entire range of brightness levels.