In Photoshop U can use Curves from Adjustments palette or Brightness/Contrast and in Camera Raw all adjustments are non-destructive.
improving Americas image
Improving America's image by helping poor and disadvantaged countries around the world.
Easiest and non-destructive (means you can change settings at any time after applying them even after saving and reopening image) way is to use Brightness/Contrast adjustments from Adjustments panel (Window > Adjustments) or go to Layer > New Adjustments Layer > Brightness/Contrast.
Image restoration means improving the image to match the original image. Image enhancement means improving the image to show some "hidden" details / bringing into evidence some part of the image. It only applies locally and is not necessarily constrained to match the original real image.
where the image's shades fall close together across the image
improving Americas image
An image enhancer is a program or tool that can improve the quality of an image by increasing its contrast, sharpness, and other attributes.
improving Americas image
Contrast
An iris diaphragm controls the amount of light admitted to a lens. Closing the iris diaphragm will decrease the brightness and increase the contrast of an image.
An image enhancer is a program or tool that can improve the quality of an image by increasing its contrast, sharpness, and other attributes. It can also be used to remove noise, artifacts, and other unwanted elements from an image.
Yes