If an image is scanned without shadow detail, it will be impossible to regain detail in an image editing program. Sharpness An attribute of a scanned image and also an attribute of a good quality scanner. It is considered desirable for an image to have good sharpness. Tone Curve A term for an adjustment available on certain scanners. The lower left end of the curve typically represents the dark portions of a picture and an upward bend will typically lighten the shadows.
Similar capabilities exist by working with the middle or highlight parts of the curve.
In this way it is possible to alter only certain tone ranges of an image without making un-wanted changes in other parts of the image. An important function that allows the user to add apparent clarity via electronic means. Unsharp masking is considered the most sophisticated sharpening method because it sharpens without the undesirable graininess that appears with other sharpening methods. An adjustment made that will determine the amount of highlight detail in an image. It is considered proper to set the white point so that the lightest part of an image will only just have zero detail.