请问打印中EMF与RAW分别是什么意思有什么区别

如题

enhanced metafile (EMF)
A type of spool file used by print spoolers on NT-based operating systems. An EMF reduces the time it takes for control to be returned to an application that makes a print request.. The GDI function calls that produce the application's graphics object are stored directly in the EMF. The time-consuming execution of these stored GDI functions is carried out later, in the background, when the spool file is played back.
Using EMF spool files also promotes printer device independence. For example, a picture that measures 2 inches by 4 inches on a VGA display and that is stored in an EMF maintains these original dimensions, regardless of the printer's resolution.

EMF Data Type
[This is preliminary documentation and subject to change.]

Enhanced Metafile (EMF) data consists of instructions to call GDI functions. The print processor must call the GDI functions to render printable images. The GDI functions make calls to the printer driver's printer graphics DLL, which renders the image and sends it to the spooler as RAW data (by calling EngWritePrinter).

NT-based operating system clients send EMF data to NT-based operating system print servers. EMF data is device independent and can be sent to a server more quickly than RAW data. A print job is also spooled as EMF data when the requesting application is local to the server, allowing a quick return to the application while the EMF data is subsequently rendered by a background spooler thread.

For more information about the EMF data type, see the Windows 2000 Professional Resource Kit or the Windows 2000 Server Resource Kit. For more information about enhanced metafiles, see the Platform SDK documentation.


RAW Data Type
[This is preliminary documentation and subject to change.]

RAW data can be sent to a print monitor without further processing. The print processor just sends this data back to the spooler (by calling WritePrinter, described in the Platform SDK documentation), sometimes inserting form feeds. An example of a RAW data file is one consisting of printer control language (PCL) commands. Print jobs are sent from client to server in RAW format if either the client or the server does not support NT-based-operating system EMF, or if a server administrator has disabled EMF support. In such cases, image rendering is performed on the client before the job is sent to the server.

Postscript commands can be considered RAW data if the target printer supports Postscript. On the other hand, the sfmpsprt.dll print processor takes Postscript input and interprets it for non-Postscript printers, so in that case the Postscript is not RAW data.

For more information about the RAW data type, see the Windows 2000 Professional Resource Kit or the Windows 2000 Server Resource Kit.

能不能不拷贝，自己说两句自己的理解！

我查了一下资料，EMF是假脱机的默认数据格式，这种格式生成的文件较小，同时几乎可以与所有的打印机兼容。RAW格式在不同的打印机上略有不同。它们是假脱机数据格式的两种。

详细的资料去哪找？

我的意思是怎么在resource kit, DDK , P SDK上找到RAW的详细资料。

[编辑 -  5/18/05 by  lsvine]

RAW就是计算机发送给打印机的实际数据流。假如PRN是打印机设备，一个
copy/b rawfile prn
命令就能把RAW文件打印出来。