How to specify dpi/resolution when saving Postscript files

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eL_PuSHeR
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Joined: Sat Apr 25, 2009 9:23 am

How to specify dpi/resolution when saving Postscript files

Post by eL_PuSHeR » Sun Jun 15, 2014 7:53 am

Hello.

Whenever I write a file to Postscript format is saved with 72dpi. Is there any way to specify resolution?

Thanks.
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cday
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Re: How to specify dpi/resolution when saving Postscript fil

Post by cday » Sun Jun 15, 2014 12:30 pm

eL_PuSHeR wrote:Whenever I write a file to Postscript format is saved with 72dpi. Is there any way to specify resolution?
The answer would appear to be no, and a Google search using the terms 'Postscript DPI' suggests that there is in fact no reason to change the default value of 72...

Postscript is a page description language which describes the content of a 'page', which in general may consist of any combination of vector text and graphics and bitmap text and graphics. When the page is printed or output to a display device, the output device reads the Postscript file, and knowing its own properties, outputs the file contents.

The visual quality of the output obtained is determined by the output device DPI, subject to any limitation set by the content of the file, for example the number of pixels available in a raster image.

By contrast, when a Postscript or PDF file containing bitmap content such as an image is opened, it is necessary to supply a DPI value to be used when the content is rasterised. The default Ghostscript and XnView DPI value for reading is 72, but that value can be changed using Tools > Options... , and in general a higher value will result in a higher quality image.

eL_PuSHeR
Posts: 267
Joined: Sat Apr 25, 2009 9:23 am

Re: How to specify dpi/resolution when saving Postscript fil

Post by eL_PuSHeR » Mon Jun 16, 2014 5:39 am

I want to create a BW Postscript file to be sent directly to my laser printer. It's just raster data. Funny enough the only software that does PS properly for me it's an ancient ms-dos program called Display.
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cday
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Re: How to specify dpi/resolution when saving Postscript fil

Post by cday » Mon Jun 16, 2014 6:49 am

eL_PuSHeR wrote:I want to create a BW Postscript file to be sent directly to my laser printer. It's just raster data. Funny enough the only software that does PS properly for me it's an ancient ms-dos program called Display.
From what I read on the Internet your laser printer will expect the Postscript file you send it to have a DPI value of 72, and will then print the file at your printer's native resolution.

What is the problem you're experiencing with files created by XnView and other software?

Edit:

If your problem is the size at which the Postscript file image is printed, I think you need to change the DPI of the source image used to create the Postscript file to obtain the desired print size, using Image > Set DPI...

eL_PuSHeR
Posts: 267
Joined: Sat Apr 25, 2009 9:23 am

Re: How to specify dpi/resolution when saving Postscript fil

Post by eL_PuSHeR » Tue Jun 17, 2014 6:03 am

OK.

Thanks for your replies.
Intel i7 5960X
Gigabye GA-X99-Gaming 5
8 GB DDR4 (2100)
GeForce GTX 970 (Gigabyte)

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