Calibrate Your Scanner

The Secret to Good Scanning: Why and How to Calibrate Your Scanner

Calibrate Your Scanner
Scanner Target from an early version of CorelDRAW.

If you have trouble getting scans that look right, the problem may not be with your scanning technique. Calibrating your scanner can go a long way toward ensuring that what you scan, what you see onscreen and what you print all look the same. Scanner calibration goes along with monitor calibration and printer calibration to get the best color match possible from three very different devices.

Color correction can be done within your image editor of choice.

However, if you find yourself having to make the same types of corrections repeatedly—scans that are consistently too dark or have a reddish cast to them, for example—calibrating your scanner can save much image-editing time.

Basic Visual Calibration

Before you calibrate your scanner, you should calibrate your monitor and printer. The next step is to scan something and make adjustments until your scanned image, your monitor display, and your printer output all accurately reflect the same colors. This step requires that you first become familiar with your scanning software and the adjustments available.

If you calibrate your printer by printing a digital test image, you can scan your print of that test image and use it to visually calibrate the scanner to the output of the printer. If you don't have a digital test image, use any high-quality photographic image with a good range of tonal values.

Before scanning for calibration, turn off all automatic color correction.

After scanning, adjust the controls on your scanner or within your scanning software and rescan until what you scan matches your monitor display and printed output. Note all adjustments and save them as a profile for future use.

Scan, compare and adjust. Repeat as necessary until you are satisfied that you've found the optimal settings for your scanner.

Color Calibration With ICC Profiles

ICC profiles provide a way to ensure consistent color across several devices. These files are specific to each device on your system and contain information about how that device produces color. If your scanner or other software comes with a pre-made color profile for your scanner model, it may give good enough results using automatic color correction.

Get an ICC profile for your monitor as well as your printer, scanner, digital camera or other equipment. If it didn't come with one, go to the manufacturer's website or contact customer support for your product.

    Scanning Targets

    Calibration or profiling software may come with a scanner target—a printed piece that includes photographic images, grayscale bars and color bars. Various manufacturers have their own images, but they all generally conform to the same standard for color representation. The scanner target requires a digital reference file specific to that image. Your calibration software compares your scan of the image to the color information in the reference file to create an ICC profile specific to your scanner.

    If you have a scanner target without its reference file, you can use it as your test image for visual calibration.

    Scanner targets and their reference file can be purchased from companies that specialize in color management.

      Scanner calibration should be redone every month or so, depending on how much you use your scanner. When you make changes to your software or hardware, it may be necessary to recalibrate.

      Color Management System

      If high-end color management is necessary, purchase a Color Management System, which includes tools for calibrating monitors, scanners, printers and digital cameras so they all "speak the same color." These tools often include generic profiles as well as the means to customize profiles for any or all of your devices. A CMS provides the most complete color management at a price, and it is usually the calibration method of choice for commercial printing companies.

      Choose the calibration tools that match your pocketbook and your needs for accurate representation of color on screen and in print.