Problem with Font Rendering in charts on PDF

10 posts, 0 answers
  1. Joe
    Joe avatar
    3 posts
    Member since:
    May 2010

    Posted 24 Sep 2010 Link to this post

    I have a report that is being exported to PDF for printing.  This report has some charts in addition to some regular text.

    The text in the charts is very "fuzzy" and pixelated.  as if it was originally rendered at a much smaller resolution/dpi and then zoomed in.  compared to other text that is the same size on the page it's terrible.

    I'm hoping that it's something I'm doing wrong as I create the report/charts.  I have attached a sample report.  this is using a horizontal stacked bar chart to produce these "diagrams".

    The second screenshot really highlights the difference.

    The original pdf is available at http://www.zfootprint.com/sample1.pdf.

    I can provide sample code/report if necessary.

  2. Steve
    Admin
    Steve avatar
    10942 posts
    Member since:
    May 2014

    Posted 27 Sep 2010 Link to this post

    Hello Joe,

    Currently the chart image is rendered as a bitmap with the resolution of the screen which is usually 96dpi. The only way to solve the problem with the print quality in PDF is to render the chart in a vector format. This request is already in our TODO list but will take some time to implement as this is not a trivial task especially for the chart.

    We apologize for the temporary inconvenience.

    Best wishes,
    Steve
    the Telerik team

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  3. Joe
    Joe avatar
    3 posts
    Member since:
    May 2010

    Posted 28 Sep 2010 Link to this post

    wouldn't it be an easier bandaid to put in an option to set the dpi for rastor images when exporting to pdf?  or just rastor at 200dpi all the time?  I believe that would improve the problem and take a lot less time to implement.

  4. John S.
    John S. avatar
    89 posts
    Member since:
    Aug 2004

    Posted 29 Dec 2010 Link to this post

    Hello,

    I am curious if this increase in resolution is a possibility?

    Ideally a vector approach is prefered; however, I sense this will not happen anytime soon (although alot of what you guys do are not trivial tasks).
    As this is a reporting solution, which in my experience results in actual printing, I find it odd that the ability to print a part of a report results in such a pixelated output. It seems the opposite case in which the copy text was pixelated and the chart printed crisp would not take years to resolve as this has taken.

    Is it possible that this issue be looked at with a more focused response than, to paraphrase, 'its real hard'. As Joe mentioned a band-aid to this issue would be an ability to scale up the pixel count.

    Thanks,
    John

  5. Jason
    Jason avatar
    1 posts
    Member since:
    Dec 2010

    Posted 05 Jan 2011 Link to this post

    This is a massive problem for printed output.

       Hashtable settings = new Hashtable();
                settings.Add("OutputFormat", "PDF");
                settings.Add("DpiX", 300);
                settings.Add("DpiY", 300);

    ... where a report chart also has its BitmapResolution set to 300 will result in jagged / pixelated output.

    I agree that Vector would be ideal but a stop gap Raster at higher DPI is needed in the interim.  Please crank up the hard-coded 96 dpi cap ... or better yet apply the BitmapResolution setting we set.  If it is a performance problem ... please let us be responsible for throwing hardware at the problem if we crank up the DPI too far.   In our case, we can wait all day for number crunching ... but we need the output to be razor sharp.

    If we can't crank up the DPI via a property, could you expose this in an XML document, config file, or registry setting?

    Thanks,

    Jason

  6. Steve
    Admin
    Steve avatar
    10942 posts
    Member since:
    May 2014

    Posted 04 Feb 2011 Link to this post

    Hi guys,

    We pushed a fix that corrects the behavior of the Chart report item and now you can use the BitmapResolution Property to define the resolution of the generated image in all formats inc. PDF. The fix is part of the internal build available in your accounts.

    In the long term we consider the vector rendering of the Chart item in PDF as a better solution and it will definitely improve the quality of the generated documents. The strongest point of the vector graphics is that they can produce images scalable to any size and detail. In contrast the raster graphics (bitmaps) are resolution dependent and they cannot scale up to an arbitrary resolution without loss of apparent quality.

    Thank you for the involvement.

    All the best,
    Steve
    the Telerik team

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  7. John S.
    John S. avatar
    89 posts
    Member since:
    Aug 2004

    Posted 04 Feb 2011 Link to this post

    Steve,

    Thank you very much on the follow up of this issue. I will give it a try. Hopefully, a vector implementation will be available in the foreseeable future; however, this update is sincerely appreciated.

    John

  8. John S.
    John S. avatar
    89 posts
    Member since:
    Aug 2004

    Posted 25 Mar 2011 Link to this post

    Hi,

    This is just a follow-up regarding the resolution. I finally got to try things out and it looks MUCH better. Thank you.

    I hope you guys are looking into the vector integration and interface (which I admittedly didn't get to play with much, but I am guessing it didn't change). Setting a chart up seems to be a difficult thing to do compared to some of the other features that exist.

    Again, thank you so much for adding the resolution property.

    Sincerely,
    John

  9. Keith
    Keith avatar
    19 posts
    Member since:
    Aug 2012

    Posted 23 Aug 2013 Link to this post

    has this issue been resolved using the graph item?

  10. John S.
    John S. avatar
    89 posts
    Member since:
    Aug 2004

    Posted 23 Aug 2013 Link to this post

    Hi Keith,

    The newer Graph (vs Chart) control takes care of this issue. I have been using it with great results.

    John S.

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