# pstopnm - convert a PostScript file to a PNM image - man - [phpMan] > **TLDR:** Convert a PostScript file to a PNM image. > - Convert a PS file to PNM images, storing page N of the input to `path/to/fileN.ppm`: `pstopnm {{path/to/file.ps}}` - Explicitly specify the output format: `pstopnm -{{pbm|pgm|ppm}} {{path/to/file.ps}}` - Specify the resolution of the output in dots per inch: `pstopnm -dpi {{n}} {{path/to/file.ps}}` *Source: tldr-pages* --- _Pstopnm_ _User_ [_Manual_(1)](https://www.chedong.com/phpMan.php/man/Manual/1/markdown) General Commands Manual _Pstopnm_ _User_ [_Manual_(1)](https://www.chedong.com/phpMan.php/man/Manual/1/markdown) ## NAME pstopnm - convert a PostScript file to a PNM image ## SYNOPSIS ### pstopnm [**-stdout**] [**-forceplain**] [**-help**] [**-dpi=_**dpi_] [**-xsize=_**pixels_] [**-ysize=_**pixels_] [**-xborder=_**frac_] [**-yborder=_**frac_] [**-landscape**] [**-portrait**] [**-nocrop**] [**-pbm** |**-pgm** |**-ppm**] [**-llx=_**s_] [**-lly=_**s_] [**-urx=_**s_] [**-ury=_**s_] [**-verbose**] [**-xmax=_**pixels_] [**-ymax=_**pixels_] [**-textalphabits=**{**1**,**2**,**4**}] _psfile_[**.ps**] ## OPTION USAGE Minimum unique abbreviation of option is acceptable. You may use double hyphens instead of single hyphen to denote options. You may use white space in place of the equals sign to sep‐ arate an option name from its value. ## DESCRIPTION This program is part of [**Netpbm**(1)](https://www.chedong.com/phpMan.php/man/Netpbm/1/markdown). **pstopnm **reads a PostScript file as input and produces PBM, PGM, or PPM images as output. This program simply uses GhostScript to render a PostScript file with its PNM device drivers. If you don't have GhostScript installed or the version you have installed was not built with the relevant PNM device drivers, **pstopnm **will fail. You can see if you have the proper envi‐ ronment by issuing the command gs --help . If it responds and lists under "Available De‐ vices" **pbm**, **pbmraw**, **pgm**, **pgmraw**, **pnm**, **pnmraw**, **ppm**, or **ppmraw**, you're in business. It's important to understand that **pstopnm **is a Netpbm image file format converter only in the broadest sense of the word, because Postscript is far from an image file format. What **pstopnm **really is is a Postscript renderer - an image generator. One place you'll notice the difference is where you expect pstopnm | pnmtops to be idempotent (which is not the case). There are details on this kind of conversion below. **pstopnm **uses the value of the **GHOSTSCRIPT **environment variable as the file name for the Ghostscript program. If **GHOSTSCRIPT **is not set, **pstopnm **searches your **PATH **for a regular file named **gs**. If it doesn't find one, it assumes Ghostscript is in the file **/usr/bin/gs**. **pstopnm **does not use the Netpbm libraries to generate the output files, so may not be en‐ tirely consistent with most Netpbm programs. _psfile_[**.ps**] is the name of the input file. **pstopnm **will add the **ps **to the end of the name you specify if no file exists by the exact name you specify, but one with **.ps**added does. For Standard Input, use **- **or just don't give any argument. If you use the **-stdout **option or your input is from Standard Input, **pstopnm **outputs images of all the pages as a multi-image file to Standard Output. Otherwise, **pstopnm **creates one file for each page in the Postscript input. The files are named as follows: If the input file is named **psfile.ps**, the name of the files will be **psfile001.ppm**, **psfile002.ppm**, etc. The filetype suffix is **.ppm**, **.pgm**, or **.pbm**, depending on which kind of output you choose with your invocation options. If the input file name does not end in **.ps**, the whole file name is used in the output file name. For example, if the input file is named **psfile.old**, the output file name is **psfile.old001.ppm**, etc. Note that the output file selection is inconsistent with most Netpbm programs, because it does not default to Standard Output. This is for historical reasons, based on the fact that the Netpbm formats did not always provide for a sequence of images in a single file. When your input is from Standard Input, you may feed multiple Encapsulated Postscript docu‐ ments, one after another, and **pstopnm **converts every document and places it in the Standard Output stream as an image. But if your input is from a named file, **pstopnm **expects the file to be an Encapsulated Postscript file, which means it contains only one Enapsulated Post‐ script document. If the file contains multiple concatenated documents, **pstopnm **ignores every document but the first. This distinction does not exist for non-EPSF Postscript input - **pstopnm **generates an output image for each page of the input regardless of whether the input is from Standard Input or from a named file. Note that you can generate both kinds of files - concatenated EPSF and multi-page non-EPSF - with **pnmtops**, selecting with the **-setpage **option. Each output image contains a rectangular area of the page to which it pertains. See the Di‐ mensions section for details on what part of the input image goes into the output image and how big it is in the output and what borders and margins are in the output image. It has been reported that on some Postscript Version 1 input, Ghostscript, and therefore **pstopnm**, produces no output. To solve this problem, you can convert the file to Postscript Version 3 with the program **ps2ps**. It is reported that the program **pstops **does not work. ### Dimensions This section describes what part of the input image gets used in the output and the dimen‐ sions of the output, including borders and background. Note that an output image is associated with a single input page. **pstopnm **starts by taking a rectangular area from the input page. That is called the subject image. **pstopnm **may add borders to the subject image to form what is called the bordered subject im‐ age. **pstopnm **places the bordered subject image in the center of the output image and clips the edges as necessary to fit the computed output image size. The location of the subject image in the Postscript input page is defined by four numbers, the lower left corner and the upper right corner x and y coordinates. These coordinates are usually specified by the BoundingBox DSC statement (a Postscript comment) in the PostScript file, but they can be overridden by the user by specifying one or more of the following op‐ tions: **-llx**, **-lly**, **-urx**, and **-ury**. The presence and thickness of a border to be added to the subject image to form the bordered subject image is controlled by the options **-xborder **and **-yborder**. If **pstopnm **does not find a BoundingBox statement in the input, and you don't specify image area coordinates on the com‐ mand line, **pstopnm **uses default values. If your input is from Standard Input, **pstopnm **does not use the BoundingBox values (because of the technical difficulty of extracting that infor‐ mation and still feeding the file to Ghostscript), so you either have to specify the image area coordinates or take the default. The output image size is a confusing thing. In a Postscript file, things have spatial dimen‐ sions. For example, a particular line may be 3 centimeters long. A Postscript printer is supposed to print the line 3 centimeters long, using however many pixels that takes, without regard to how big the sheet of paper on which it is printing is. In a PNM image, by con‐ trast, there is no spatial dimension; there are only pixels. You might have a line that is 100 pixels long, but the PNM image says nothing about how long that line should be on a printed page. **pstopnm **fills the role of a Postscript printer. The PNM image is a virtual printed page. **pstopnm **must determine how many pixels it will use in the output image to represent an inch of input image, which is the "output device resolution." Think of it as the number of dots per inch the virtual printer prints on the virtual page. The simplest thing is for you to tell **pstopnm **exactly what output device resolution to use, using the **-dpi **option. If you say for example **-dpi=300 **and the bordered subject image is 2 inches by 3 inches, the PNM output will be 600 pixels by 900 pixels. Using this method, the output device resolution has to be the same in both directions. Or you can set the output image dimensions with **-xsize **and **-ysize**. For example, if you say ### -xsize=1200 -ysize=1800 output image is 1200 by 1800 pixels, with each pixel representing 1/600 inch of input image. In the unlikely event that you want different output device resolutions in the two direc‐ tions, you could use **-xsize **and **-ysize **to do that. In the above example, if you change ### -ysize If you specify one of **-xsize **and **-ysize **and not the other, **pstopnm **defaults the other such that the output device resolution is the same in both directions. The "x" and "y" of **-xsize **and **-ysize **refer to the image being printed on the page, not the page. So if **pstopnm **prints it in landscape orientation, "x" would pertain to the vertical direction on the page, i.e. the vertical direction in the output PNM image. If you specify neither the output size nor the output device resolution, **pstopnm **does some weird computation which exists mainly for historical reasons: If you specify **-nocrop**, **pstopnm **uses the values of **-xmax **and **-ymax **for the output image di‐ mensions. These default to 612 and 792 pixels, respectively. The final case, the default, is where you don't specify any size or resolution options or ### -nocrop device resolution that would generate the number of pixels indicated by **-xmax **and **-ymax **from the bordered subject image. Then, based on that resolution, it chooses an output image size that is just large enough to accommodate the subject image (no borders). Remember (above) that **pstopnm **trims the edges of the bordered subject image to fit the computed output size. ### Ghostscript Limitations Tests done in 2013 with Ghostscript 8.71 indicate that Ghostscript's **pgmraw **output driver has some kind of rounding error that causes the pixel values to change slightly, and that means **pstopnm **generates incorrect output when you have monochrome Postscript input. But with color Postscript input, **pstopnm **uses Ghostscript's **ppmraw **output driver and generates correct PPM output. ### Usage Notes There is some good advice on converting to and from Postscript, in the document Postcript File Conversions" (1) by Andrew T. Young. ### Reversible Conversion If you're trying to do the equivalent of the naive pnmtops | pstopnm, the following steps will do it. $ pnmtops -nocenter -equalpixels -dpi 72 -noturn testimg.ppm > testimg.ps $ pstopnm -xborder=0 -yborder=0 -xsize=_XSIZE_ -ysize=_YSIZE_ \ -portrait -stdout -quiet testimg.ps >testimg2.ppm _XSIZE_ _and_ _YSIZE_ _above_ _are_ _the_ _image_ _dimensions,_ _which_ _you_ _can_ _get_ _from_ _testimg.ps_ _like_ _in_ _the_ _following_ _example_ _(the_ _grep,_ _awk_ _and_ _echo_ _commands_ _are_ _just_ _to_ _help_ _demonstrate_ _how_ _the_ _other_ _commands_ _work_ _-_ _you_ _wouldn't_ _use_ _those_ _in_ _a_ _program)._ $ grep "BoundingBox" testimg.ps %%BoundingBox: 0 0 227 149 $ awk '/%%BoundingBox/ {print $4,$5}' testimg.ps 227 149 $ xysize=$(awk '/%%BoundingBox/ {print "-xsize="$4,"-ysize="$5}' testimg.ps) $ echo $xysize -xsize=227 -ysize=149 $ pstopnm -xborder=0 -yborder=0 $xysize -portrait ... testimg.ps Note that Ghostscript bugs can keep this from doing a perfect reversible conversion. ## OPTIONS In addition to the options common to all programs based on libnetpbm (most notably **-quiet**, see [ Common Options](index.html#commonoptions) ), **pstopnm **recognizes the following command line options: ### -forceplain forces the output file to be in plain (text) format. Otherwise, it is in raw (bi‐ nary) format. See [**pbm**(1)](https://www.chedong.com/phpMan.php/man/pbm/1/markdown), etc. Use this instead of the **-plain **common option if you need plain format output. ### -llx=_ selects _bx_ as the lower left corner x coordinate (in inches) on the Postscript input page of the subject image. See [the Dimensions section](#dimensions) . ### -lly=_ selects _by_ as the lower left corner y coordinate (in inches) on the Postscript input page of the subject image. See [the Dimensions section](#dimensions) . ### -landscape renders the image in landscape orientation. If you specify neither **-portrait **nor **-landscape**, **pstopnm **chooses the orientation that best fits the image on the output page. Landscape means printed sideways on the page, not printed the long way. Those are different things if the long edge of the page is the top one. ### -portrait renders the image in portrait orientation. See **-landscape**. ### -nocrop This option causes **pstopnm **to make the output image exactly the dimensions of the bor‐ dered subject image. By default, **pstopnm **makes the output image the dimensions speci‐ fied by **-xmax **and **-ymax**. See [the Dimensions section](#dimensions) . ### -pbm ### -pgm ### -ppm ### -stdout causes output to go to Standard Output instead of to regular files, one per page (see description of output files above). Use **pnmsplit **to extract individual pages from Standard Output. ### -urx=_ selects _tx_ as the upper right corner x coordinate (in inches) on the Postscript input page of the subject image. See [the Dimensions section](#dimensions) . ### -ury=_ selects _ty_ as the upper right corner y coordinate (in inches) on the Postscript input page of the subject image. See [the Dimensions section](#dimensions) . ### -verbose prints processing information to stdout. ### -xborder=_ specifies that the left and right borders added to the subject image are to be _frac_ times the subject image width. The default value is 0.1. See [the Dimensions section](#dimensions) . ### -xmax=_ specifies that the output image is to be _xmax_ pixels wide. The default is 612. See [the Dimensions section](#dimensions) . ### -xsize=_ specifies that the output image is to be _xsize_ pixels wide. See the Dimensions sec‐ tion . ### -yborder=_ specifies that the top and bottom borders added to the subject image are to be _frac_ times the subject image height. The default value is 0.1. See [the Dimensions section](#dimensions) . ### -ymax=_ specifies that the output image is to be _ymax_ pixels high. The default is 792. See [the Dimensions section](#dimensions) . ### -ysize=_ specifies that the output image is to be _ymax_ pixels high. See [the Dimensions section](#dimensions) . ### -dpi=_ specifies the output device resolution, in dots per inch, of the Postscript printer that **pstopnm **simulates. This is the number of PNM pixels **pstopnm **generates for each inch of image. See [the Dimensions section](#dimensions) . This option was new in Netpbm 10.21 (March 2004). ### -textalphabits= This controls subsample antialiasing of text. Antialiasing is a form of smoothing that eliminates jagged edges on characters. Subsample antialiasing is a kind of an‐ tialiasing that uses subpixels in a box, and the value of this option is the size of that box. 4 gives you the best looking output, while 1 causes no antialiasing. Smaller numbers make **pnmtops **use less CPU time. Pstopnm uses Ghostscript's **TextAlphaBits **parameter for this. The default is 4. This option was new in Netpbm 10.53 (December 2010). Older versions of **pstopnm **do no antialiasing. ## LIMITATIONS The program will produce incorrect results with PostScript files that initialize the current transformation matrix. In these cases, page translation and rotation will not have any ef‐ fect. To render these files, probably the best bet is to use the following options: pstopnm -xborder 0 -yborder 0 -portrait -nocrop file.ps Additional options may be needed if the document is supposed to be rendered on a medium dif‐ ferent from letter-size paper. ## SEE ALSO **gs**, [**pnmtops**(1)](https://www.chedong.com/phpMan.php/man/pnmtops/1/markdown), [**psidtopgm**(1)](https://www.chedong.com/phpMan.php/man/psidtopgm/1/markdown), [**pbmtolps**(1)](https://www.chedong.com/phpMan.php/man/pbmtolps/1/markdown), [**pbmtoepsi**(1)](https://www.chedong.com/phpMan.php/man/pbmtoepsi/1/markdown), [**pnmsplit**(1)](https://www.chedong.com/phpMan.php/man/pnmsplit/1/markdown), **pstofits** ## COPYRIGHT Copyright (c) 1992 Smithsonian Astrophysical Observatory PostScript is a Trademark of Adobe Systems Incorporated. ## AUTHOR Alberto Accomazzi, WIPL, Center for Astrophysics. ## DOCUMENT SOURCE This manual page was generated by the Netpbm tool 'makeman' from HTML source. The master documentation is at **** netpbm documentation 06 December 2013 _Pstopnm_ _User_ [_Manual_(1)](https://www.chedong.com/phpMan.php/man/Manual/1/markdown)