If you have several scanners connected to your computer, please select a scanner before proceeding with scanning. You select the scanner by clicking on the menu item Main č Select Scanner in the main screen. If you want to change the initial scanner setup click on the Setup button and/or click on the menu item Preferences č Scanning to select one or more of following settings: Turbo Scanning, Invert Scanning, Auto Load/Eject, Consistent Resolution, Use All Resolutions, Use Low Memory Option, Use Large ASPI Buffers and Paper Load.
To set all the parameters that control the scanner use the scanner settings toolbar available in the Prescan-, Scan- and Copy Station. The parameter settings include the size of the paper that you are scanning as well as the resolution(dpi) in which you are scanning. These parameters must be set no matter what scanner you are using. If either of these settings are changed, the scanner will reload the paper and start scanning from the top. In the following the scanner settings will be described. See also ACS Scanning.
Width
You can select a scan width from the width combo box. The selectable units in the combo box correspond to the scale displayed on the front of the Full Scale Scanner. Instead of the Units you can select Auto Crop which automatically removes the white area all around the image. You can also select one of the 5 standard sizes from A to E (or A4 to A0 when outside US).
Dpi
You can select a scan resolution from the dpi combo box. The selectable resolution units are the ones supported by the scanner. The resolution defines the detail level and is defined by the number of dots (pixels) per inch (dpi) captured horizontally and vertically. For instance 300 dpi is equivalent to 90,000 pixels per square inch.
Thresholding
The scanner "sees" the drawing in 256 graytones and by setting the mode to "256 Graytones" the file produced will represent what the scanner produces. Scanning in graytones is normally not acceptable, as it produces very big files. The scanner has several ways to transform these 256 graytones to black and white images. This is called thresholding. You can also control the way you want to threshold the scanner by setting the mode in the scanner setting toolbar. There are a number of different ways to do this, depending on what scanner you are using. If you change the way you threshold the scanner, the scanner will reload the paper and start scanning from the top.
Mode - 256 Graytones
For each pixel 256 gray levels are recognized. This way of thresholding will give you a file representing what the scanner picks up. Use this mode with caution, as the resulting file will be very big (E-Size drawing at 300 dpi will produce a file at 120 MB). This way of thresholding is good for very bad/difficult drawings as the resulting file can be thresholded to a black and white image, using a raster editor, by an operator in a semi automatic way. All scanners support this thresholding mechanism.
Mode - B&W Manual Threshold
When scanning with the mode set to B&W Manual Threshold the whole drawing is thresholded by specifying one value, the threshold. The threshold can be set to a value from 1 to 256. If the threshold is set to 180, all pixels that have a graytone on 180 and above is set to black and all other pixels are set to white. The right way to determine the best threshold is by prescanning the drawing and changing the threshold until an acceptable result is found. This way of thresholding is good for drawings where the contrast is the same on the whole drawing. All scanners support this thresholding mechanism.
Mode - Automatic Adaptive Threshold
When scanning with mode set to Automated Adaptive Threshold the scanner uses the built in digital signal processor to determine the best threshold for small areas in the drawing. This means that the contrast level of the drawing can vary a lot and you still get a crisp clean image as the result. If for example the drawing should have a threshold on 120 in the left side of the drawing but a threshold of 180 in the right side of the drawing, the digital signal processor will recognize this, while you when scanning with B&W Manual Threshold would have to choose either of the thresholds. This mode can also be used when scanning good originals, that is, drawings that could have been scanned with Manual threshold, and give good results. This means that using Automatic Adaptive Threshold is a very good choice when scanning a lot of different types of drawings. In other words, if you need a high throughput, Automatic Adaptive Threshold is in most cases the best choice. When scanning in this mode, 2 parameters can be set: Adaptive Level and Background Suppression. The Adaptive level works like the threshold. The lower value you specify the more of the drawing is picked up. A value of 10 works well with most drawings. A Background Suppression of 0 will work well with most drawings, but it can be raised to suppress background noise in the image. Both parameters can be changed on the fly, while scanning. This thresholding mechanism is supported by all DSP scanners that are FSS 5200 DSP, FSS 8300 DSP etc.
The following 3 modes are only supported by the FSS 8300 , FSS 8300 PLUS. When scanning in either of the 3 below mentioned modes, one parameter: Level, can be set. Level works like threshold, if you lower the value, the scanner will pick up more of the drawing.
Mode - B&W Adaptive
This is the normal mode, suitable for scanning all kinds of drawings, including difficult blueprints, brown transparents (sepias) etc. This mode provides minimum file sizes being well suited for digitizing.
Mode - Gray Adaptive
This mode adds halftones to the image and is suitable for display or print files of light to medium dark drawings. The added toned shades of gray provide a pleasing result for printouts of drawings, but make files of extended size and are not well suited for digitizing.
Mode - Auto Photo
This mode makes halftones suitable for photos. The halftoning provides a good result for printouts of photos. This mode makes very large files that are not well suited for digitizing.
Following 4 modes are only supported by the MAGNUM, CHROMA and PANORAMA scanners.
Mode – B&W Copy Normal
Dual 2D-Adaptive enhancement with ADL+ error diffusion half toning and 2D-Auto edge enhancement and 2D-Adaptive background suppression. This mode is suitable for copying (scan and print) of normal drawings with a reasonably good quality. Halftones are distributed throughout the image for softer transitions between black and white.
Mode – B&W Copy Photo
Dual 2D-Adaptive enhancement with ADL+ error diffusion half toning. This mode is suitable for copying (scan and print) of continuous shades of gray like in photos. Halftones are distributed throughout the image for softer transitions between black and white.
Mode - B&W Copy Adaptive
Dual 2D-Adaptive enhancement with ADL+ error diffusion half toning, 2D-Adaptive Thresholding and 2D-Adaptive background suppression. This mode is suitable for copying (scan and print) of Sepia, Blueprint and other originals with heavily distorted foregrounds and backgrounds where the shades that create unwanted “noise” are close to the shades that make up the image’s data and the two are hard to differentiate.
Mode – Adaptive with Background Level
Similar to Automatic Adaptive Threshold
Mode - Color Scanning
IDEALScanOS offers scanning in 24-bit color, if the attached scanner supports this. Scanning in color can however be a little more complicated than scanning in black and white. A large format drawing will require a lot of memory. If your PC is equipped with a lot of memory you can go ahead and scan your color documents way as when scanning in black and white. If your PC has a low amount of memory installed, 64 MB or less, you will have to use some of the workarounds described later on in this chapter
To take full advantage of the speed of the scanner, it is a good idea to turn on the Use Large ASPI Buffers option. This can be found under the PreferencesčScanning menu.
Color Setup
The Ideal scanner range does offers the ability to download gamma curves to the scanner. The gamma curves can be setup on the Preferences menu point to Scanning and click Color Setup. This will display the following dialog:
You can set the gamma curves individually for each color, or use the Lock feature to set the gamma curves identically for all 3 colors.
Instead of setting up gamma curves these can be auto generated by setting a single Brightness and Contrast value. This makes it easier to get the right colors.
The black and white reference point can also be set from this dialog. By setting these points you determine the amount of highlight and shadow detail during scanning in one of the Color or Graytone Modes. By adjusting the white point you determine the amount of highlight detail in the scanned image. The white point should be set so that the lightest part only just shows no detail. Adjusting the black point will determine the amount of shadow detail in the scanned image. The black point should be set so that the darkest part only just shows no detail.
The Blur effect can also be set in this dialog. The Blur filter blends graytones and thus removes unwanted “noise” from the image. The value you set determines the degree of graytone blending. ·
Memory considerations
A large drawing scanned in 24-bit color can easily require more than 400 MB RAM if it’s all held in memory. Most PC’s does not have this amount of memory installed. IDEALScanOS offers a special scanning mode, which does not require much RAM. To use this feature, move to the Main Station, on the Preference menu point to Scanning and hit Use Low Memory Option.
When scanning in color (and graytone) with the low memory option, the scanner data is written to disk while scanning. This will ensure that the memory requirement is low.
There are some disadvantages by using this option.
· You must decide for a drawing size before starting the scan operation.
· You must decide for a filename before starting the scan operation.
On the other hand, you can scan in color on a PC with “only” 64-128 MB RAM.
Once the file is scanned, keep in mind, that you need a lot of memory to load the image in the Archive station.
Color Calibration
Why Calibration?
Since the light detectors in all color scanners are affected with usage, RGB output signals can vary. Age usually affects color balance and linearity, while the chromacity components are relatively stable.
To ensure long term stability and reproduction of color scans, the scanner linearity, color balance and chromacity can be calibrated, using the IT8 Calibration Sheet (ANSI IT8 standard reflective target) shown in the next figure:
IT8 Calibration Sheet
Some monochrome scanners support basic calibration. Basic calibration reduces noise in the dynamic area and ensures stable and clean scans. For example it reduces the unwanted effects caused by dust particles when scanning at high resolutions.
How to calibrate the scanner?
It is recommended to let the scanner warm up for 1 complete hour before calibrating. Slight intensity changes can occur in the scanner’s florescent lights just after turning the scanner on. The cameras can also shift slightly during the first minutes of start up. The 1 hour warm-up time will ensure stabilized light conditions and camera heights. The stabilization will ensure that the conditions during calibration match those during scanning.
¨ Select Calibrate Scanner from the Main Menu in the Main Station.
¨ The Calibration Wizard will guide you through the calibration process. For color scanners, there are three main steps: Basic Calibration, Graytone Calibration and Color Calibration. For monochrome scanners that support calibration, only the first step -Basic Calibration will be necessary.
¨ Follow the wizard’s instructions regarding insertion of the Basic Calibration Reference. See your scanner documentation for details on the Basic Calibration Reference supplied.
¨ Follow the wizard's instructions regarding insertion of the IT8 Calibration Sheet. You will be requested to make two insertions for each scanner camera: once for graytone calibration and once for color balance calibration.
¨ You start with graytone calibration of the first camera, move on to the next camera, and so forth. The last camera is graytone and color calibrated after which you move backwards, inserting the sheet for color calibration until you return to the first camera. The Wizard gives you the exact insertion points for each camera.
What Happens During Calibration?
IDEALScanOS scans the RGB color value of each patch, converts to CIE-Lab color space (where color distances correspond better with human vision). Comparing with the known reference CIE-Lab values of the IT8 target, the software calculates the scanner's color correction for each patch.
IDEALScanOS automatically builds the color tone transfer tables and correction matrix and uploads them to the scanner.
Consistent Resolution
Consistent Resolution makes the scanner use the same resolution in all stations. When disabled separate resolutions can be set for the prescan-, scan- and copy station. Setting a lower resolution in the prescan station will make the scanner scan faster.
Use all available Resolutions
As default only a selected numbers of resolutions are displayed. If the scanner supports more resolutions they can be added to the combo box, by moving to the Main Station and activating the menu item PreferencesčScanningčUse All Available Resolutions.
Paper Load Option
Paper can be loaded to the scanner either from the left- or right hand side or from the center. Default is left hand side.
Use Low memory Option
When the Use Low Memory Option is enabled IDEALScanOS will scan graytone and color images directly to disk. This will not require as much memory as normal operation. The drawback is that you will need to scan in JPEG format and that the image cannot be manipulated after end of scan operation.
Use Large ASPI Buffer
When the Use Large ASPI Buffer option is enabled IDEALScanOS communicates with the scanner using internal system buffers instead of it’s own buffers. This will make the scanner run a lot faster when scanning in graytone and color. Not all adapters support this feature.