Auto Levels Command in Photoshop

Auto Level Command

The Auto Levels command automatically adjusts the black point and white point in an image. This clips a portion of the shadows and highlights in each channel and maps the lightest and darkest pixels in each color channel to pure white (Level 255) and pure black (level 0).

The intermediate pixel values are redistributed proportionately. As a result, using Auto Levels increases the contrast in an image because the pixel values are expanded. Because Auto Levels adjusts each color channel individually, it may remove color or introduce color casts. Auto Levels gives good results in certain images with an average distribution of pixel values that need a simple increase in contrast.

Do the following to do Color correction by Auto Level Command:

For example I am taking this picture:

I.Click on Image menu > Adjustment > Auto Levels. The application of Auto Levels is automatic with this option. 

However, you can adjust any of the options in the following steps:

1.Click on Layer menu > New Adjustment Layer and choose either Levels or Curves.

2. In the Levels or Curves dialog box, click the Option button.

3. Select Enhance Per Channel Contrast under Algorithms in the Auto Color Correction Options dialog box.

4. Adjust the amount of shadow and highlight values that are clipped and adjust the target color for the midtones.

5. Click OK in the two opened dialog boxes to apply Auto Levels.