Images often need a little adjusting to get ideal print or display results.
Select Colors › Levels. A dialog opens for controlling the levels in the image.
Good results can usually be obtained by clicking Auto. To make manual adjustments to all channels, use the dropper tools in All Channels to pick areas in the image that should be black, neutral gray, and white.
To modify an individual channel, select the desired channel in Channel. Then drag the black, white, and middle markers in the slider in Input Levels. You can also use the dropper tools to select points in the image that should serve as the white, black, and gray points for that channel.
If Preview is checked, the image window shows a preview of the image with the modifications applied.
When you are finished, click OK.