Overview

MicroStation´s Raster Manager is an application that lets you control the display of one or more image files within a MicroStation design file view. When installed, each view in a design file may be used to display image files.

Information on the image files is stored with the design file.

MicroStation´s Raster Manager supports PostScript and HPGL2/RTL devices, as well as all raster devices supported through the Windows Print Manager.

In a typical Raster Manager session where aerial photography is used, a design file view contains a mosaic of images depicting the region of interest. The mosaic can include an unlimited number of images each referenced to the vector data contained in the active design file and any references attached to it. Similarly, using Raster Manager, you can assemble a group of rendered images for printing.

Whether you print to a color or gray scale PostScript device, images from various sources can be assembled together and the colors for each image are represented correctly in the output. With this flexibility, you can integrate black and white scanned documents, gray scale or color aerial photographs, monochrome bitmap layers, satellite imagery and design files to produce a full color document on color devices or a gray scale document on gray scale devices.

MicroStation´s Raster Manager lets you produce hybrid prints of raster images along with raster vector data and design vector data. To produce such a hybrid print for a view, choose Print from the MicroStation File menu.

Printing devices for Raster Manager

MicroStation´s Raster Manager lets you print to raster devices supported by the Bentley Drivers as well as all raster devices supported through the Windows Print Manager.

MicroStation´s print driver file creates the vector and raster data portions of the print file. The print file includes information about both the vector data and raster data of your image.

Every supported printing device has a print driver file with file extension “.plt,” which controls the printing process. Your system´s print file is “printer.plt.”

Printer selection guide

You can use the following table as a guide to help you choose the correct Bentley printer driver file.

Vector and raster transparency is not available with most printer drivers (rip*.plt drivers only support transparency).

Output to:	Printer Driver File	Pros	Cons
Standard large format printer, that accepts HPGL/2, HP RTL (such as HP and Xerox)	printer.plt	Lets you access manufacturer specific features such as: Host based color correction and paper handling (stapling, folding)	Large amounts of vector and raster data can cause printer driver to consume large amounts of host memory and possibly fail. Vector and raster transparency not available.
	hpglrtl.plt	Fast generation of output file by MicroStation. User specification of paper sizes.	No access to manufacturer specific features. Vector and raster transparency not available.
Desktop printer	printer.plt	Lets you access manufacturer specific features.	Vector and raster transparency not available.
	ripwin32_gray8.plt ripwin32_rgb24.plt	Lets you access features only available via the RIP (vector and raster translucency).	May require a large amount of processing time on the host. The amount of data sent to printer can be large. For example, a design file with 500 vectors will be much larger in raster form than in vector form.
PostScript output	pscript.plt pscriptc.plt epscripm.plt epscripc.plt	Lets you generate PostScript for use in documents (EPS), or to be post-processed to PDF, or can be sent to a PostScript printer.	When sending to a printer, no access to manufacturer specific features. Vector and raster transparency not available.
	pdf.plt	Lets you directly create PDF documents.

Raster Manager's Print toggle (default ON)

This toggle enables or disables the printing of Type 90 raster images. It has no effect on the printing of Type 87/88 rasters. You can find the toggle in the following menus:

• Raster Manager dialog box

• Attachment Settings dialog box > Display/Print tab

Output/Printing Resolution

It is recommended that you select the maximum possible number of pixels per inch for the output resolution. You can use a lower resolution to obtain a quick draft output but the higher resolution should be used to obtain high quality output.

The printing resolution for Raster Manager images is set by editing the PIXEL_RESOLUTION keyword in the chosen printer driver. The range of values spans from 1 to 300 dpi, the default being 75 dpi.

To set the resolution in the driver

1. Using a text editor, open the plt file you will use to generate the print file.


2. Search for the following keyword: PIXEL_RESOLUTION=, and set its value to the desired resolution (1 to 300). Default is 75 dpi.


3. Save and exit.

Maximum Resolution

To ensure maximum quality for your print, you should set this value to the same resolution as that of your printing device. With devices that use half-toning, however, the maximum resolution that you can achieve is the net resolution after half-toning (that is, the net resolution will be less that the overall resolution of the device). Since a value set higher than necessary usually does not provide added resolution, it is advisable to determine the optimum value to minimize the size of your print file.

Calculating the optimum output resolution

To calculate the output resolution that will produce the smallest print file size:

• Determine the net resolution of your device. This value should be less than the resolution of the printer.

• The Raster Manager default value is 75, since it is the typical net resolution for 300 dpi printers that print in gray scale with half-toning.

• Optimize your print file size by determining whether your print requires the full available resolution.

  Use the following formula to optimize the print file size:

  (Image Width/Pixel Size) / Width of print = Optimal Resolution.

  For example, if the image width is 1000 feet, the pixel size is 1 foot and the width of the print is 5 inches, then:

  (1000/1) / 5 = 200 dpi

Use the Raster Manager: Files () dialog box to find the pixel size and the image dimensions (select the appropriate image in the Raster Manager: Files () dialog box and get the values from the Pixel Size field under the Files list box). In this example, the maximum quality output can be achieved with a resolution set at 200 dpi. Consider also: Any higher value creates a larger print file but does not increase quality. If the net (true) resolution of your device is lower than 200 dpi, then any value higher than the true resolution also creates a larger print file but does not increase quality. In this instance, if your device does not contain the true resolution necessary to achieve the maximum possible resolution inherent in your image, then your print quality cannot be maximized.

After the Maximum Resolution is set, the Output Size of Raster Data field displays the amount of raster data that will be created. The total size of the PostScript file also includes the vector data.

Printing images

Printing images from Raster Manager is similar to standard printing, except that only particular printer driver files can be used.

To print Raster Images

1. From the MicroStation File menu, select Print.
   The Print dialog box opens.


2. From the Print dialog box, in the Printer and Paper Size field, choose one of the following: Windows Printer - output is sent directly to the Windows system printer OR Bentley Driver - the Save Print As dialog box opens, to let you specify a name and location for the print to be saved to disk.


3. If Bentley Driver was chosen, select a printer driver suitable for your Bentley Driver printer.


4. Click OK.
   The Select Printer Driver File dialog box closes.


5. In the Print dialog box, click the Print icon.
   or
   From the Print dialog box´s File menu, choose Print.
   If you are outputting to the Windows printer or are using Raster Image Processor drivers, when you select Print, the image file is processed and then printed. If you are outputting to a printer other than the system printer, the Save Print As dialog box opens.


6. Choose the name and location for the output print file.


7. Click OK.
   The print file is created on disk.
   When your output is to a Bentley Driver, the print file is saved to disk. To print the (saved) print file, requires that you complete one more step.

To print out your print files

1. Open an MS-DOS window.


2. Change the directory to where the print file is located.


3. Use the key-in
   COPY /B <filename> <printer_port>.
   Where <filename> is the name of the print file and <printer_port> is the port to which the printer is attached (such as lpt1:)
   Printing begins when the printer receives the print file (containing the image according to the selected parameters).

Additional information about print configuration files

Before you try to print rasters, the appropriate statements must be present in the printer driver. If the appropriate statement(s) are not present in the driver's configuration, the user will not have any control over the appearance of the printed results.

For specific information and guidance in configuring and using the driver associated with a printer, you can open the printer driver file that you intend to use in an appropriate text editor, such as Windows Notepad. You can then follow the instructions in the file to configure the printer driver. You can also access this file through the Print dialog box.

To edit the current printer driver file

1. From the Print dialog box's File menu, choose Edit Printer Driver. The text editor (such as Notepad) opens the file associated with the selected printer driver.


2. Make any changes that you require and save them (choose File > Save in Notepad).


3. From the Print dialog box's File menu, choose Reload Print Driver, to include any changes in the loaded file.

The following table list the mandatory statements for printing raster files. They are found in the .plt files that allow printing of raster images.

Raster Manager - Type 90 Elements Statements

STATEMENTS	DESCRIPTION/USE
PIXEL_RESOLUTION=75	Specifies the printing resolution for Raster files. Values span from 0 to 300, the default value being 75.
GRAYSCALE=0	Enables/Disables grayscale printing of raster files. 1=On, 0=Off, Default=0.
BACKGROUND=2	Used to specify the background color of monochrome rasters in Raster Manager. If BACKGROUND =0 or 1 (white or black), the foreground is inverted if identical to the MSv8 background. If BACKGROUND=2 (color), no changes are brought to the monochrome raster. Default=0.
RTL_PLOT_ON_THE_FLY	This statement is edited when large print files get to exceed the installed memory on a printer device. See paragraph on RTL Printing below.
CONTRAST=50	Defines the percentage of contrast applied to the image being printed. Default=50.
BRIGHTNESS=50	Defines the percentage of brightness applied to the image being printed. Default=50.
NO_RASTERREF=0	Enables/Disables printing of raster images. 1=Don't Plot, 0=Plot, Default=0.

RTL printing - Exceeding Installed Memory on printer

If you are not using the Print Manager to print files, it may happen that the raster portion of the print does not fit entirely into the printer´s memory. When this happens, several options are available:

• Add more memory to the printer.

• Reduce the size of the print file by reducing the resolution or paper size.

• Use the Plot On The Fly Feature.

The Plot On The Fly feature is activated by setting a special variable into your .plt file. When this variable is found, MicroStation generates the print file in such way that when the printer´s memory is full, it:

• Stops input of data.

• Starts the drawing.

• Starts input and printing of data one band at a time until it reaches the end of the file.

This method is slower but allows printing large raster files on a printer with minimal memory installed.

The only condition to use this feature is for the design file to entirely fit into the printer´s memory. Conventional ways require that the raster data be spooled first and then the vector data (design file). When using Plot On The Fly, the vector data is spooled first. This method ensures that no matter how large the raster portion is, it will never outrun the printer´s memory.

Using Plot On The Fly always produces translucent vectors. Vector information will be transparent and some colors, like yellow, may not show properly when an aerial photograph is beneath the vector data.

To modify the .plt file for Plot On The Fly

1. Using a text editor, or using the File > Edit Print Driver menu in the Print dialog box, open the .plt file you will use to generate the print file.


2. Do a search to find the following keyword:
   RTL_PLOT_ON_THE_FLY and set its value to 1 (enabled).


3. Save and exit.

To send the print file to the printer

1. Open an MS-DOS window.


2. Change the directory to where the print file is located.


3. Key in the following:
   mode lpt1 retry=p.
   This instructs the copy command to try sending data to the printer until it responds. The printer will not respond until it has completed processing the data from its memory.


4. Send your file to the printer by typing:
   copy /b <filename> <printer_port>.
   Where <filename> is the name of the print file and <printer_port> is the port to which the printer is attached (such as lpt1:)
   The prompt returns when the copy command finishes copying the print file to the printer port.



This can take several minutes to several hours depending on the amount of raster data remaining to be plotted when the Plot On The Fly mode begins. Your computer will be tied up for the duration of the process. Remember, the remaining raster data is spooled one band at a time.