I've been tinkering with Ghostscript with a port monitor(on a HP PCL 6 Universal driver) to convert print job into PDF. I've tested with a few applications such as Words, Excel, Adobe Reader, Microsoft Edge etc and they are all working properly.
However upon testing Microsoft Powerpoint 2016, it seems like there are some graphics that are unable to be rendered properly through Ghostscript.
Actual Slide Below
Output From Ghostscript in PDF Below
I've tested this even with some other PDF generators such as BioPDF,CutePDF as well as AdobePDF and they would all result in the same output as above.
Just wondering has anyone tried and have faced similar issues before? if so could someone point me in the right direction??
What you are doing isn't a single step PowerPoint to PDF and Ghostscript is not rendering the PowerPoint. In fact if you are creating a PDF file Ghostscript isn't (ideally) rendering anything.
What's actually happening is that you are asking PowerPoint to print to a canvas, which is then passed to the PostScript printer driver. That produces PostScript which is sent to the Port. Your (and others) Port Monitor then sends the PostScript to the 'Distiller' (in your case Ghostscript and the pdfwrite device). The Distiller reformats the vector drawing commands into a PDF format and builds a PDF file from them. It doesn't render (turn into a bitmap image) anything unless forced to.
Obviously there are several places along that road where the problem could creep in. Given that you say that the Adobe product (the others you mention al use Ghostscript) has the same problem, I think its safe to assume that the problem isn't Ghostscript.
This also means that you aren't using the driver you think you are. Adobe can't handle PCL as an input medium as far as I'm aware, and nor can Ghostscript. GhostPCL will handle PCL as an input, but that's not what you say you are using.
Of course you haven't linked to an example file to demonstrate the problem, nor supplied an example command line, so this is all supposition.
Now if, somehow, you are using a PCL6 device, then the problem is most likely due to the presence of rasterOps in the output. Rasterops are part of the PCL imaging model which do not exist in PDF and are a form of transparency. There are three ways to handle such content for a PDF output device; firstly render the whole page content to an image, secondly ignore the rasterOps objects, thirdly treat the rasterOps as opaque.
GhostPCL and the pdfwrite device take the third option. So, its just conceivable that your original content has some transparent objects which are being handled as rasterOps by the PCL printer driver, and then rendered as opaque by GhostPCL and the pdfwrite device.
If that's somehow the case then the solution is simple; don't use a PCL printer driver, use the PostScript one.
If you post a link to a (simple, eg single page) example of what you are sending to Ghostscript, and a command line, then I can look at it. Please don't send me the PowerPoint, I can't use it and even if I could, my print setup would not match yours. I need the data being sent to Ghostscript.
[EDIT after looking at files]
Don't mean to sound like I'm lecturing, the problem is people find these result on Google searches and then try to apply them based on a poor understanding of what's happening. So I find it best to be really clear in my answers about what's going on. It saves questions later :-)
The first thing I see is that the PCL is indeed PCL, and if you try running that through Ghostscript it throws horrible errors and exits. So presumably you aren't doing that.
The PostScript file contains nothing except huge images, rendered (presumably at 600 dpi) contains 2 pages, the two pages look like your images above. Which is why the PostScript is better than 20 times larger than the PCL file.
But.... If I open the .ppt file with OpenOffice (4.0.0 is what I have to hand) I see exactly the same thing. I don't, I'm afraid, have a copy of Microsoft PowerPoint, but from what I see here there are two conclusions;
firstly that the PDF I get looks pretty much like the PowerPoint when viewed with OpenOffice at least. So there's something 'interesting' about your PowerPoint.
secondly, even if that's not what you expect, its what's in the PostScript program. That means that either PowerPoint rendered the slide to a bitmap or the Windows printing system/HP driver did.
Now, if I run the PCL through GhostPCL instead of Ghostscript (rendering, not producing a PDF) then the result is more like what I think you are expecting. However, when sent to a PDF file the result is horrible. Which strongly suggests to me that there's some form of transparency involved, PostScript doesn't support transparency at all, and PCL does it through rasterOPs.
I'm afraid that this means that the problem lies either in PowerPoint, the Windows print system or the PostScript printer driver you are using. Since the PCL is at least close to what you expect, I suspect that this means PowerPoint is doing the right thing, and its the printer driver messing up. It appears you are using the Windows PostScript printer driver.
So there's no way you can 'fix' this for files like this, at least not with Ghostscript. You would need to 'fix' the Windows PostScript printer driver, or possibly the Windows print system. You could try reporting a bug to Microsoft, presumably these files print incorrectly when sent to physical PostScript printers too.
Related
Morning, everyone,
Quick question about PS2PDF. I use it to convert graphics that I produce directly in postscript to PDF. While there is no visual problem on PS files, I see a grid on my PDF viewer. At first I thought the problem was in the viewer, but it remains present when I compile my TeX files containing the figures with PDFLaTeX. Do you have any ideas for settings that can "fix" this display? Thanks in advance :)
Evince is independent of Ghostscript as far as PDF files are concerned, but I don't know how it can be viewing PostScript files.
I believe what you are seeing is an artefact of the PDF rendering engine in use, and the way the PDF file is constructed (which is itself dependent on the way the PostScript is constructed).
Much of the content is drawn by creating little rectangles which are intended to butt up against each other (and basically do). However, depending on the resolution, the precise numerical accuracy of the calculations and the accuracy of the co-ordinates, it can be the case that these rectangles do not quite touch ideally. There is a theoretical gap between them.
You can see this occur with Adobe Acrobat, and zooming in and out changes where the lines appear (it changes the effective resolution, thereby changing the calculations from user space to device space, ie to the actual pixels on screen).
I cannot say for sure that the same problem exists with Evince, but I expect it does. Withh Acrobat I can turn off anti-aliasing, which is where the problem really arises. Acrobat is attempting to insert an anti-aliased pixel between the two rectangles, which leads to these faint lines. Turning it off (In Acrobat X Edit->Preferences->PageDisplay->Smooth Line art) makes the lines disappear.
Ghostscript doesn't apply anti-aliasing by default, so these lines don't appear when rendering either the PostScript or the PDF files, but if I turn on anti-aliasing (-dGraphicsAlphaBits=4) then Ghostscript renders the lines in both the PostScript and the PDF file.
Essentially I think the problem is that your PDF viewer is using anti-aliasing and your PostScript viewer isn't, so they don't look the same.
I am using an online PDF generator to generate the attached PDF.
While the PDF opens and looks OK on adobe Acrobat (I tested several different versions including Reader and Pro) the transparent layers are printed as white boxes when sent to printer (either a real printer or another PDF printer like PDFill PDF&Image Writer.
Any idea what's wrong with the transparent layers and how to fix them?
This is the file: https://dl.dropboxusercontent.com/u/18517313/flyer.pdf
There doesn't seem to be anything wrong with the file to me, and it prints apparently correctly for me when printed from Adobe Acrobat. How are you printing the file ?
One workaround would be opening the file in Acrobat Pro, and use the Flattening Preview (to be found among the Print Production Tools) to flatten the transparencies.
When you print a PDF (or any other format) from an application, several sub systems are involved. The application (such as Adobe Reader) makes calls to the graphics subsystem of the OS (such as GDI on Windows). The OS, in turn passes these calls to the printer driver which is responsible for converting these calls (such as draw line, fill path, etc.) to instructions that are understood by the printer that you selected. These instructions are referred to as the page description language or PDL. Examples of PDLs are PostScript and PCL. This abstraction is good because applications no longer need to ship their own printer drivers. The downside is that the API of the graphics subsystem and the PDL both put restrictions on the richness of your graphics.
Transparency is a typical feature that is present in PDF but only limited available in PostScript. To achieve the same visual result, the feature is approximated. In case of transparency this is called flattening as Max Wyss points out.
By the way, applications (such as Adobe Acrobat) may choose to by-pass the OS and driver and generate the PDL themselves. This is referred to as pass-through printing. Although this circumvents the limitations of the graphics subsystem, the output is still bound to the PDL of your printer.
I have a small PDF file, which is supposed to display just the string "Hello World!".
Unfortunately, it displays black boxes instead of the characters. I suppose there is some problem with the fonts, but I am not sure.
Is there a way to diagnose and troubleshoot this issue? All I see on the Internet is advices to do this and to do that, which helps to some and does not to others (nothing helped me). Looks like shooting in the dark to me.
Here is a concrete example. Why does this PDF display black squares instead of the string Hello World ?
EDIT
A bit of the context. I am trying to convert a trivial HTML to PDF using the wkhtmltopdf tool. It is an absolute frustration, because according to the Internet searches the tool is supposed to work and do it quite well. But the thing does not work for me and nothing I do changes this! Unfortunately, this tool seems the only free tool to convert HTML to PDF. This is a huge bummer.
If you want to find out whether a PDF is valid or what is wrong with it, there are a few general steps you can take:
1) Open it in Adobe Acrobat or Adobe Reader (on a desktop platform, not a tablet device). For a very long time the PDF format was owned by Acrobat and the way their software handles PDF is still close to the gold standard. However, there is a caveat with this; Acrobat is very, very smart in the way it handles PDF files and it will overlook or actively correct a number of mistakes other PDF engines might have a problem with...
2) Get yourself a preflight tool. These tools were invented for use in graphic arts, but have applications outside of it too. Popular examples are callas pdfToolbox (warning, I'm affiliated with this vendor!) or the "Preflight" plug-in you'll find in Adobe Acrobat Pro (which is actually also callas technology under the hood). Then preflight specifically against the PDF/A-1b or PDF/A-2b standard.
That last point deserves some more explanation. You should pick a PDF/A compliant preflight profile because the PDF/A (or PDF for Archival) standard is extremely picky. It's goal is to make sure that PDF files will still be readable in exactly the same way 50 years from now and to ensure that it tests a whole range of properties of the file itself and the different components in it. You might be able to ignore some of the errors you get (because some of them will be connected to the fact that the PDF/A identification isn't correct for example) but I wouldn't ignore any other errors unless you understand exactly what they mean and why they aren't relevant.
PS: Can you make your test file available some other way? The file you shared in your question is useless I think. When I do "Download" I get a PDF file that doesn't contain text and doesn't have fonts in it. Those rectangles you see are exactly that - rectangles. So this PDF renders fine - it's the PDF generation process (or the fact that you stored the file on Google docs - I really have no clue what that might do) that went berserk apparently.
In addition to David's hints (first using a known good viewer and then some preflight tool), there is a third level in the inspection process:
3) Inspect the PDF with your own eyes and with the PDF specification (made available by Adobe here) at hand in a text viewer (for a first impression) and (if the cause of the issue at hand is not immediately visible) then in a PDF browsing tool (for in-depth analysis).
This step is quite cumbersome at first but after some time you learn your way around in the PDFs.
A sample for such a PDF browser tool is RUPS but there are others around, too.
'Small PDF file supposed to display "Hello World!"'
Not correct. The file you linked to does not contain any code that could render pixels on screen or on paper that a human brain would read as "Hello World!". The file indeed does only contain vector drawing operations which result in 12 black boxes.
The command line tool pdffonts does not indicate any font being used in the file:
pdffonts so-file-#15858199.pdf
What could still cause the "rendering" of the words you are looking for: some vector or pixel drawing code contained in the PDF. To find out about this, you'll have to look into the low level source code of the PDF.
The original file is 1.570 Bytes. So this task looks not as being overly huge.
'Is there a way to diagnose and troubleshoot this issue?'
Using qpdf, a "command-line program that does structural, content-preserving transformations on PDF files", you can expand all contained streams (which are normally compressed):
qpdf --qdf --object-streams=disable so-file-#15858199.pdf qdf-#15858199.pdf
The resulting file, qdf-#15858199.pdf, is 3.875 Bytes. Now open it in a text editor. PDF object no. 6 (lines 66-219) contains the contents of the page. Lines 123-194 contain only the operators m (moveto), l (lineto) and h (closepath). These lines contain 12 different groups of drawing commands, where each one represents the path for one of the 12 black boxes you see rendered on screen or printed on paper:
102.400001 12.8000001 m
268.800004 12.8000001 l
268.800004 179.200002 l
102.400001 179.200002 l
102.400001 12.8000001 l
h
Line 196 contains
f
which is the fill operator to actually fill black color into so far constructed (closed) path. Nothing in the other lines (which I didn't analyze in detail) does any drawing that may resemble the shapes of any glyphs.
'Unfortunately, this tool seems the only free tool to convert HTML to PDF'
Not correct either.
1.
Assuming your "free" is meant as free as in liberty, then an alternative option is HTMLDOC.
HTMLDOC does not support specific fonts which may be assigned to your HTML input via CSS, but it does a good job in converting one or multiple HTML documents into a single PDF book containing chapters, page-numbering, page headers and footers and more. For all options available, see its full documentation.
2.
Assuming your "free" is meant as free as in beer, then an alternative option (for private usage only) could be PrinceXML.
PrinceXML does an extraordinarily good job when it comes to support almost all CSS features your HTML document may be using. See its documentation and also some of the sample PDF files produced by PrinceXML.
I'm generating PDF files and they look OK in Acrobat Reader. However, when I try to print documents to different printers, selecting the same "Fit To Page" scaling option, the results are a bit different.
One printer leaves a bit different page margins and space between characters.
Is it generally possible to achieve exactly the same looking printouts on different printers with the same scaling options? If yes, is there some sort of check-list for that?
You can never guarantee the output from device to device. This is because the printer interpret what you send it, and often uses built-in fonts and other resources that might be slightly different from manufacturer to manufacturer. You could do the following to help:
Embed all fonts into the PDF (including system fonts)
Force the printer driver to download all fonts and not use the ones internal on the device
Whenever possible, don't scale, send it down in the native size. This might mean that you have to make the output small enough to fit in the print window of a wide range of printers
The other thing to keep in mind is that when printing PDF files, if you use Postscript, there is a high likelihood that Acrobat Reader will do the PDF to PS conversion and pass it through the driver. You probably see an option in the print driver relating to this. Leaving it on pass-through should give you more consistent results.
There is also an option in Acrobat Reader to "print as image". This will slow printing dramatically but could assist.
If you have an application that is sending this file to print keep in mind that many newer printers support native PDF printing. This means you can simply fire the PDF at the device itself and not have to view or print it from Acrobat. In this case you are doing one less conversion / interpretation, so it could help.
I have built an application that automates the filling out of form fields inside a pdf. It then takes various assets and combines them together to generate a "print ready" product. All of this is accomplished using the magic of iTextSharp. When form fields are populated, they are then flattened to text. The problem is that even with the fonts embedded they aren't really attached to the form fields in a meaningful way (like straight text elements are) and the printers are complaining that the pdf is generating licensing errors due to this. I researched this a bit and it just seems to be the nature of how form fields are.
The artists we are working with requested that we research a way to "outline" the text that is created from flattening the form fields. I found that running the PDF Optimizer with a custom preset allows for Text Outlining in Acrobat, and even better I can generate an Acrobat Sequence that runs this command on the pdf. The problem is that Sequences can not be automated, at all.
I found a plug-in called AutoBatch that allows for the execution of Sequences on the command line through a batch file. The downside is that this would require installing Acrobat Pro and the Plug-in on the server this application will be running on. Further it seems like an overkill solution just to outline the text in the pdf. For all I know at this point iTextSharp may allow me to do this programmatic, but searching for such a thing on google returns little results and nothing relevant.
So the question: Is there a better way to outline text in a pdf than the current solution I have implemented or am I kind of stuck?
TLDR; PDF is generated w/ non-standard fonts. I need to "outline" this text to send it to the printer. Currently using AutoBatch Acrobat Plug-In to execute Acrobat Sequence from the Command Line. Seems excessive, wondering if anyone knows a better way to automate font outlining.
I am also in a printing environment and have used forms for "Box Covers" plenty of times to shorten the code used to produce box covers.
I simple us "pdfStamper.FormFlattening = true;" and the printers (Xerox DP180 and DC5000) has no problems in using the PDF.
The moment I leave out FormFlattening the printer gives a lot of errors regarding the PDF.
If you are using FormFlattening then check if the printer has the font locally installed in order for it to reference the font from the print engine instead of the PDF resources.