Saturday, March 26, 2011
Auto Levels works best on images that have a reasonably even distribution of tonal values throughout the image, as it redistributes pixels based on white and black points, with a tendency to increase contrast.
Auto Color removes unwanted colour casts in an image without adjusting the contrast in an image.
1. To apply Auto Levels to an image, choose Image>Adjust>Auto Levels.(Use Edit>Undo if you do not like the result.)
2. To apply Auto Color to an Image, choose Image>Adjust>Auto Color. (Use Edit>Undo if you do not like the result.
Auto Levels adjusts each colour channel in the image individually. As a result, it may remove or introduce colour casts.
Both Auto Levels and Auto Color generally produce good results, but they do not allow the precision of manual adjustments that you can make using the Levels and Curves dialogue boxes