PDF rendering in Preview

Discussion in 'OS X El Capitan (10.11)' started by flyx, May 2, 2016.

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  1. flyx macrumors newbie

    Joined:
    Mar 29, 2016
    #1
    Preview was once a great PDF viewer. Since the last two or three OSX versions, it became less great, and I wonder what has happened.

    This is a part of a PDF with editable fields (the numbers can be edited), when I fill them in with Preview:

    [​IMG]

    Note how the baseline between the filled-in text and the preexisting text is off. This is what is rendered by Adobe Reader DC:

    [​IMG]

    Okay, so Adobe highlights the editable fields blue, let's ignore that. It also seems to have problems with the character heights in the captions, let's ignore that too (this is not a thread for making fun of Adobe). The important thing is that it places the numbers where they are supposed to be, which is vertically centered in the field and on roughly the same baseline as the captions.
    Now for the interesting thing: I save this PDF with Adobe Reader and then reopen it in Preview:

    [​IMG]

    Suddenly, the numbers are correctly placed! But as soon as I edit a number in Preview, it is misplaced again. I am interested in why this happens, and also in whether I can craft the PDF document in a way that is a workaround for Preview's baseline problem. Can someone shed some light on this?
     
  2. ferretex macrumors member

    ferretex

    Joined:
    Apr 9, 2015
    #2
    In Snow Leopard is still awesome; in El Capitan is horrible. Miss the old days.
     
  3. KALLT macrumors 601

    Joined:
    Sep 23, 2008
    #3
    Preview has never supported the standard fully and there are numerous compatibility problems. The development of the standard is actually still on-going, but Apple has just not kept up. Preview also still exports PDF files in version 1.3 (cannot say for sure whether that is true for El Capitan), which was released in 2000, whereas the current version is 1.7 (since 2008).
     
  4. campyguy macrumors 68040

    Joined:
    Mar 21, 2014
    Location:
    Portland / Seattle
    #4
    I cropped out most of the post I'm replying to. You're first "question" (there wasn't a question mark...) is that IMHO nothing's "happened". Preview works perfectly well, given the constraints of the file format the app was/is designed for. Anyone who offers otherwise is not - IMHO - following what "PDF" was/is designed for, which I've posted here in MR's Forums before. Picking on just the "current version" is easy - which "Version 1.7" (no offense, KALLT) Version 1.7, or Version 1.7 (Adobe Extension Level 8)?

    Scour the forums for some of my posts related to PDF files. I picked on one of my former clients - Metro (in Portland OR), which has posted several bike route maps, created on Macs (I've been in their offices since the mid-90s, so I know...). Some of their PDF files have hundreds - not dozens, but hundreds - of non-standard fonts and non-system fonts. I downloaded one of their (relatively-massive) PDF files that took lots of time to load and render, then used my local installation of Illustrator to replace 305 specific fonts with System fonts and sent it to several of my friends/clients - my optimized file loaded in 3-4 seconds to load and panned around "?instantaneously" as opposed to the "laggy" panning experienced by the original file(s) (found here: http://www.oregonmetro.gov/tools-living/getting-around/bike-there/bike-resources).

    Simply put, design for the final product. Adobe "abandoned" designing PDF for the future recently, Apple cut their ties a few years ago. Don't blame Apple as even Adobe has cut its ties to "PDF" - lots of decent free viewers are available, and its a matter of time before Adobe's free options "suck". Design for your consumers - I do, and have for 15 years.
     
  5. flyx thread starter macrumors newbie

    Joined:
    Mar 29, 2016
    #5
    Well my PDF file rendered correctly under (I think it was) Snow Leopard, so something happened since then. I also noticed that as soon as I open the file with Adobe Reader, the file is changed (i.e. it asks to save the file when I close it). So I guess the Reader transforms something that Preview does into the „correct“ format or something.

    Few free readers support PDFs with editable forms. Some (like Skim) use PDFKit, so they suffer from the same problems as Preview. libpoppler, the „free“ PDF implementation, doesn't really support editable forms (afaik), and quite some free readers are based on that. The only free reader I know that supports it (besides Adobe's products) is the PDF-XChange Viewer, which is only available for Windows.
     
  6. maflynn Moderator

    maflynn

    Staff Member

    Joined:
    May 3, 2009
    Location:
    Boston
    #6
    Preview does a great job, not all PDFs will behave perfectly, whether you're talking about Preview, Adobe or other products. The issues you highlight are minor, especially for a product as powerful as Preview and its free, unlike Adobe's.

    I've used Preview to fill in information on more then one occasion and yes, at times, it may not be aligned perfectly, but it got the job done and it still looked nice.

    See even the Adobe product is having issues, and if you're not going to ignore OS X's preview app with some of its minor issues, Why give Adobe a pass on its failings?

    Apple's rendering engine is slightly different then Adobe's.
     
  7. flyx thread starter macrumors newbie

    Joined:
    Mar 29, 2016
    #7
    It doesn't look nice anymore when the space of the editable field is just enough to fit the text in.

    I am not arguing for Adobe's software, I just wanted to show how exactly Preview's output differs from what's expected.

    This was my first thought, but seeing that Preview does render it correctly when it is saved with Adobe Reader, it seems to be more likely that the problem lies within the way Preview enters the text in PDF's data model.

    I do not intend this thread to be a general rant at Preview (or Adobe Reader), I am rather searching for a solution of the problem at hand. If I can get more insight about why exactly this problem occurs, I might be able to adjust the PDF so that it doesn't happen anymore.
     
  8. maflynn Moderator

    maflynn

    Staff Member

    Joined:
    May 3, 2009
    Location:
    Boston
    #8
    My suggestion and I don't mean to sound harsh, is not to use Preview. It seems the rendering engine is not providing results that fit your need, where as the output of Adobe Acrobat is. I've used both and I find Acrobat to be more feature rich, but I guess you have to expect that since you're paying $$ for the use of that app.
     
  9. campyguy macrumors 68040

    Joined:
    Mar 21, 2014
    Location:
    Portland / Seattle
    #9
    One other "bit" that could be leading to this issue you're experiencing is how SL and EC place and handle fonts. In the last couple of OS X iterations fonts aren't all placed in a Fonts or user's Fonts directory, and some devs - using MS with their Office and OneNote apps are embedding fonts directly in an app's Contents>Resources>Fonts folder along with other font-related resources. Some PDF reader apps attempt to render font information/appearance - some do it better than others, and there's no cross-app means to get around this. A workaround is to ensure all of the relevant fonts are in an accessible directory/folder (such as the system's Fonts folder) and rebooting, but there's no guarantee that all of your apps will recognize those fonts - OS X's licensed Visual Postscript has been doing a decent job over the years but IMHO the SIP restrictions may hinder efforts to get things looking as you want them to...

    The only two real ways to get this looking right - besides maflynn's preferred method - is to flatten/rasterize the document for viewing by others (using the source application), or to use the Windows version of Acrobat DC to embed the relevant fonts in a document (which is what I do when I'm sending PDFs to others when keeping searchable/editable text is desired).
     
  10. Mcmeowmers macrumors 6502

    Joined:
    Jun 1, 2015
    #10
    I have the same pain as you OP. All other PDF viewers just blow through the battery but Preview manages to mess somethings up. My personal favourite is when zooming or resizing the Preview window text is rendered blurry. To fix it you have to press the Zoom to Fit or zoom in then zoom out buttons
     

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