Easy Technique To Improve Image Scansby Anita Cross
s a photographer with thousands of photographs taken with slide film, I have a lot of experience with scanning photographs. One effect of the scanning process that seems nearly universal, with any of the equipment I have used, is a slight loss of contrast that leaves the image appearing a bit "muddy".
This is very easy to cure in Photoshop, using Levels.
I prefer to use Levels in Adjustment layers, one each for Black, White, and occasionally, Gray. The advantage of using Adjustment layers is you are not actually changing the image. And fine tuning the adjustment later, if necessary, is just a double-click away.
Let's keep this basic, and work with a relatively small, single layer image.
First, locate an area of the image that contains black or nearly black pixels and zoom in to 200%. Now open an Adjustment layer and select "Levels". You can do this from the menu bar by selecting Layer -> New Adjustment Layer -> Levels.
In the resulting window, name the layer "Levels, Black". Click on OK, and the Levels dialog box will open. On the right, below a set of six buttons, you'll find three "eye dropper" icons. From left to right, the icons represent Black, Gray and White. Click on the Black eye dropper.
Now click on the image on one of the nearly black pixels. Using your keyboard, hold down the control key and press the "0" key (Ctrl+0) to fit the image on the screen. You can then select and de-select the Preview option to see the effect on the image. If necessary, click on another area of nearly black pixels in the image. Once you are happy with the effect, click on OK.
Repeat the process, this time zooming in on an area of the image that is nearly white. Open a new adjustment layer and name it "Levels, White". Click on the White eye dropper in the Levels window, then click on the image on one of the nearly white pixels. Display the whole image on the screen and Preview the effect. If necessary, click on other areas of nearly white pixels until you achieve the desired effect. Then click on OK.
You can then repeat the process once more, using the Gray eye dropper. I have found adjusting the Gray level, for scans from my film scanner, to be unnecessary more often than not. However, that may not hold true for your scanned images.
To make changes to the Levels at any time, simply double-click on the corresponding adjustment layer in the Layers palette. This will open the Levels dialog box, allowing you to make further adjustments.
Easy to master and quick to use, this technique may soon become the first process you apply to all your scanned images.