PDF to EPS or PS to EPS conversion maintaining page size - pdf

Question

I need to convert a PDF or Postscript file to EPS, I tried using Ghostscript with the following command to convert Postscript to EPS:
gswin32.exe -o output.eps -sDEVICE=eps2write -dFitPage input.ps
Or PDF to EPS:
gswin32c.exe -q -dNOCACHE -dNOPAUSE -dBATCH -dSAFER -sDEVICE=eps2write -o output.eps -dFitPage input.pdf
They both complete successfully but they are not maintaining the page size. The input PDF or PS files are the same drawings and they both a page size of 300x300pts. You can download these files here and here. They look like this:
But after converting them to EPS the results are these, PS to EPS and PDF to EPS. They look like this, the first one is the result from PS to EPS and the second one is the result from PDF to EPS (they are opened using EPS Viewer that rasterizes the image that's the reason for the low quality):
As you can see, none of them have the original 300x300 pts size, I've tried many Ghostscript options but I can't manage to get an EPS with the right Bounding Box. I just need to convert a PDF OR PS to EPS, whatever is easier or gives better results.

Answer 1

What you are asking for is, more or less, the exact opposite of what is normally required.
In general people want the EPS Bounding Box to be as tight as possible to the actual marks made by the EPS, because the normal use for an EPS file is to 'embed' it in another document. If you want extra white space you would normally add it around the EPS when you embed it.
Indeed, the EPS specification says that the BoundingBox comment should not include the white space. On page 8 of the EPSF specification:
"For an EPS file, the bounding box is the smallest rectangle that encloses all the marks painted on the single page of the EPS file"
Messing with Ghostscript switches isn't going to do anything helpful for you here, the device explicitly records the marks that are made by the input, and sets the BoundiongBox from those.
Perhaps if you were to explain why you want to have an EPS file with incorrect BoundingBox comments it would be possible to make some suggestions, but Ghostscript is doing exactly what it should do here.
[addendum]
(see comment below, this is in reply)
I suspect you need to change your process in some way then. One solution is to have the PDF start by filling the entire page with white. Contrary to many people's expectations that counts as making a mark on the page so the entire page would then be considered as the BoundingBox.
As long as you are using the Ghostscript eps2write device you could also parse the document for %%BeginPageSetup, the eps2write device still writes the original document size out in this section, Eg:
%!PS-Adobe-3.0 EPSF-3.0
%%Invocation: path/gswin32c -dDisplayFormat=198788 -dDisplayResolution=96 -sDEVICE=eps2write -sOutputFile=? ?
%%BoundingBox: 101 132 191 256
%%HiResBoundingBox: 101.80 132.80 190.30 255.20
%%Creator: GPL Ghostscript GIT PRERELEASE 951 (eps2write)
....
....
%%EndProlog
%%Page: 1 1
%%BeginPageSetup
4 0 obj
<</Type/Page/MediaBox [0 0 300 300]
/Parent 3 0 R
/Resources<</ProcSet[/PDF]
>>
/Contents 5 0 R
>>
endobj
%%EndPageSetup
You can see here that the original media size was 300x300, even though the BoundingBox correctly reflects the marks made on the page. Note! This is characteristic of EPS files produced by the current version of eps2write, it won't work for EPS files from other sources and may not work with eps2write in the future.
Other than that you're stuck with finding the media size from the input and passing it separately to the program doing the insertion, presumably by putting the data in some other text file to accompany the EPS. Or, of course, manually or programmatically editing the urx,ury co-ordinates of the BoundingBox.
Ghostscript isn't going to do this for you I'm afraid.