Knowledge Base

Category: AutoCAD
Topic ID: 62
Title: Plotting to Raster File
Created: 0000-00-00Last modified: 0000-00-00

A popular inquiry from AutoCAD users is how to plot a drawing to a raster file (or bitmap/picture). This is often in response to the need to provide a 'picture' of the drawing without actually providing the DWG, or perhaps a drawing is to be displayed in a web page. 

First is the simple to use (but less control) command called BMPOUT. It creates a Windows Bitmap .BMP file, appropriate for Paintbrush but not ready for a web page. It captures the whole drawing viewport so center your drawing as well as possible before issuing the command. The following procedures can be used to 'plot' your drawing to a raster file. 

For AutoCAD R14 

Setup: 

Issue the PREFERENCES command.

Choose the Printer tab.

Choose the New button.

Choose Raster File Formats.

Enter a Description such as 'Raster Plot'.

Choose an output resolution.

(Consider the resolution of the target device, if the output is to a display, you may want to use 1024x768 or less)

Choose a raster format.

(None of the choices are ready for web output, but the Windows BMP format is easily converted to such a format with raster converters).

Choose Monochrome or Color.

(If its a single color line drawing, choosing mono can make for a smaller file, otherwise 256 color is your best choice)

Specify the background color.

(The default is 0=black, acceptable for display but would consume much ink/toner if output. So consider color 255 for light white.)

Hit enter for 'Change Anything'

Choose OK to close the dialog.

Use: 

Issue the PLOT command.
 
Choose the 'Device & Default Selection' button.
 
Choose the 'Raster Plot' setup previously.
 
Choose the 'File Name' button and designate a file.
 
Proceed to plot as normal, the output going to the file.
 

For AutoCAD R2000+ 

Setup: 

Choose File > Plotter Manager.
 
Choose 'Add-A-Plotter Wizard'.
 
Choose Next, then Next again (accepting My Computer).
 
Under Manufacturers, choose 'Raster File Formats'.
 
Under Models, choose 'Portable Network Graphics PNG'.
 
(details on why below)
 
Choose Next until the Finish button becomes available.
 

Use: 

Issue the Plot Command.
 
On the Plot Device Tab, choose the PNG output created.
 
Choose the Properties button, and choose the output
 
resolution desired.
 
In the lower right corner, specify the path and filename
 
to create.
 
Switch to Plot Settings tab, specify the window and
 
complete the plot to file.
 

Why PNG? 

You may wonder why the PNG file was chosen. It is a clean highly compressed format. In comparison, the JPG (JPEG) format is absolutely NOT a desirable format for representing linework in raster format. While JPEG is fine for photographs, it is a 'lossy' compression and will produce noticeable 'snow' on line drawings, especially diagonal lines. 

The PNG file is your best choice for raster output, or GIF. It is very compact in size and is a 'loseless' compression. It can be displayed by all 'current' web browsers as well. 

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