Scanner / Monitor Calibration 101
SignIndustry.com - The Online Magazine for the Sign Trade.
Home | Site Map | Buyer's Guide Search  
Event Calendar Article Archive Message Boards Classifieds Product Showcases News Advertise Search Join Now

CATEGORIES
  3-D Signs
  ADA
  Architectural
  Awnings &
  Flexible Face
  Banners
  Business Development
  CNC Routing
  Computer Technology
   Articles
   Product
   Showcase
   Message Board
   Tips & Tricks
  Digital Imaging
  Dynamic Digital
  Electric
  Estimating
  Finishing & Lams 
  Flatbed UV
  Garment Decoration
  Installation
  LED Displays
  LED Lighting
  Neon & LED
  Channel Letter
  Outdoor
  Painted Signs
  Screen Printing
  Sublimation
  Vinyl Signs
  Hot Shots
  Press Releases
  Tips & Tricks
  Industry Resources
  Books
  Event Calendar
  Associations
  Business Center
  Retail Sign Shops
  Advertising Info

SignLab from CADlink


Scanner / Monitor Calibration 101

Easy and inexpensive ways to calibrate your scanner

By Larry Chan

Ok, you’ve just bought a new scanner and brought it back to your workshop. You’ve hooked it up to your computer, installed all the software and after scanning a few photos, you open up those image files and notice the color of those images do not match the originals. What is going on?

RENOLIT Calendered Vinyl - Top performance for various applications

I believe this happens to most of us. Because we are so excited with our new toy, we might just skip past the most important step: Color Calibration. This month we will discuss some easy and inexpensive ways to calibrate your scanner. To begin, you should purchase a color calibration print from a professional photo equipment retailer. The print itself is a referenced color chart that is printed on real photo paper. It will make this process easier. See Fig.1.

fig. 1

If you can’t find them, you can use a good quality vinyl color chart for now.

Let’s start with the monitor: Use Fig.2 as a reference to adjust you monitor brightness and contrast. The goal here is to be able to see Black and White and all shades of gray in between.

fig. 2

  1. From Windows®, adjust your video card output to either 24 or 32 Bit Resolution.
  2. Set the monitor’s Contrast to the Maximum.
  3. Adjust the Brightness little by little until you see White on the left and shades of Gray and Black on the right.

Note: The last few shades of dark gray are very close to black. You will need to examine them closely until you can see them. But don’t over do it! If you adjust the Brightness too high, you will see that the entire screen looks like it has a layer of fog or haze over the image.

After your monitor’s Contrast/Brightness is set, you are now ready to scan the vinyl chart or the color print.

  1. Start the scanning software and set everything to default. Set the scan mode to Color, Reflective and set the resolution to 300 DPI. (See “Understanding & Choosing a Scanner, Part I” for an explanation of DPI and other terms)
  2. Use the Preview function to view your image’s location. If your software has a feature called White Point adjustment, use it to select the White part of the image and set it. Refer to your owner’s manual on how to set the White Point value.
  3. Scan the photo and save it in either TIFF or Bitmap file format.
  4. Open the image file with your image editing software.
  5. Now you can see how far off the colors are from the original. If you don’t see any difference, then you’re done.
  6. If you see the difference, make a note on which color is too much and which is not enough. These colors are based on the combination of RGB (Red, Green and Blue). Then go back to your scanning software and use the color adjustment feature to adjust those colors. (Hints: Make a note on the default values and how much you have adjusted on each color. Some software use percentages and others use numbers so you can use that as your reference. In case you didn’t like the result, you can always go back to the factory default values and start all over again.

After each adjustment, you should scan the same photo or chart again and view it. Repeat steps 5 & 6 until you get the colors as close to the original as possible.

There are a few other ways to do this. One of them is to use a spectrometer. If you really have to get the absolute correct colors, then you should look into one. They start around $750 each. But a spectrometer can also help you to calibrate your printer, so your entire system will be matched.

There are other ways to calibrate your monitor. Some graphic/photo editing programs have built-in Color and/or Gamma adjustment features. For example: Adobe® Photoshop®, Corel® Photodraw® and Paintshop Pro® have those features.

You might ask “Why not adjust the Color and/or the Contrast/Brightness after the scan?” The answer is that no matter how you adjust the scanned image, you cannot get a better result than what you have already scanned. This is why we should adjust all settings before the final scan.

The following links are some of the resources that I have gathered for you on scanning and color calibration:

Website: Adobe®
Description: Gamma adjustment
http://www.adobe.com/support/techguides/color/gamma/gamma.html

Website: ScanSoft®
Description: A lot of information on scanning
http://www.caere.com/scanners/

Website: Desktop Publishing.com
Description: Plenty of resources and useful links.
http://www.desktoppublishing.com/scanning.html

Hope you enjoyed this article and that the information helps!

Larry Chan
www.signs-etc.net

Company
Home
Advertising Info
About Us
Contact Us
Privacy Policy
Site Map
Resources
Industry Resources
Associations
Retail Sign Shops
Books
Product Showcase
Event Calendar
Tips & Tricks
Message Boards
Classifieds
Buyer's Guide Listings
Search
Add My Company
Edit My Company

 

© Copyright 1999-2017, All Rights Reserved.