The difference in brightness of a digital bitmap consists of different light points to form different shades of gray
(different tones are actually just different brightness of the three-color channel)
Commonly used tools 1 brightness and contrast advantages: intuitive operation of the interface is simple
Disadvantages: In the adjustment of the light and dark parts are adjusted by the ratio, such as improving the brightness of the dark part of the light and then add the highlights of the details are lost. If you adjust the local brightness this method does not apply
2 Color Order Advantages: Flexible image can be divided into high light gray low light region to adjust independently. You can change the color by adjusting the brightness of each channel individually, compared to the brightness and contrast tools.
Disadvantage: The adjustment of the regional type and the point to point adjustment flexibility of the curve compared with the curve are subject to some restrictions.Classification: