[Scribus] image resolution problem

[Joel Mawhorter]

On Sun, 16 Apr 2006 01:04:31 +0200
Craig Bradney <cbradney at zip.com.au> wrote:

> On Sunday 16 April 2006 00:38, Christoph Sch??fer wrote:
> > Am Sonntag, 16. April 2006 00:23 schrieb Craig Bradney:
> > > On Sunday 16 April 2006 00:23, Christoph Sch??fer wrote:
> > > > Am Sonntag, 16. April 2006 00:03 schrieb Joel Mawhorter:
> > > > > On Sat, 15 Apr 2006 22:19:23 +0200
> > > > >
> > > > > Christoph Sch??fer <christoph-schaefer at gmx.de> wrote:
> > > > > > Am Samstag, 15. April 2006 21:43 schrieb Joel Mawhorter:
> > > > > > > Thanks for the emails so far. Unfortunately none of them has
> > > > > > > solved my problem.
> > > > > > >
> > > > > > > I'll clarify a couple of things:
> > > > > > >
> > > > > > > 1. My problem has nothing to do with using PNG. The problem
> > > > > > > happens if I import the same file as a TIFF. Also the same
> > > > > > > problem occurs if I output to PDF (at 300 DPI).
> > > > > > >
> > > > > > > 2. I know how to tell the difference between a 300 DPI graphic
> > > > > > > and a 72 DPI graphic and I understand the difference in
> > > > > > > resolution of my monitor from other output devices.
> > > > > > >
> > > > > > > The problem is that when I import a 300 DPI image (say for
> > > > > > > arguments sake 300 pixels x 300 pixels), it displays the correct
> > > > > > > size for 300 DPI (i.e. 1 inch x 1 inch) but it is downsampled to
> > > > > > > 72 DPI so that any output I do includes an image at 72 DPI.
> > > > > > > Certainly I'm not the only person having this problem! I have the
> > > > > > > latest stable version of Scribus on gentoo linux.
> > > > > > >
> > > > > > > This is all I have to do to reproduce this problem every time:
> > > > > > > 1. Create a new document with default settings.
> > > > > > > 2. Create a new picture frame.
> > > > > > > 3. Right click on the frame and choose "Get Picture"
> > > > > > > 4. Select the TIFF file containing my 300 DPI picture.
> > > > > > > 5. Then output to whatever I want (PNG, PDF) and the picture is
> > > > > > > downsampled to 72 DPI.
> > > > > > >
> > > > > > > Am I missing something basic or is this a bug in Scribus?
> > > > > > >
> > > > > > > Joel
> > > > > >
> > > > > > Hi Joel,
> > > > > >
> > > > > > did you check the export settings for PDF and Bitmap files? Do you
> > > > > > get a 72 dpi image if you set export resolution to 300 dpi?
> > > > > >
> > > > > > Christoph
> > > > >
> > > > > Hi Christoph,
> > > > >
> > > > > Yes I set both to 300 DPI.
> > > > >
> > > > > Joel
> > > >
> > > > Hi Joel,
> > > >
> > > > I can't confirm this here. I tested with 1.2.5cvs, 1.3.3.1, and
> > > > 1.3.4cvs. Input: 300 dpi, output: 300 dpi.
> > > >
> > > > Would you consider an upgrade to 1.2.5cvs or 1.3.3.1?
> > >
> > > Christoph, can you also test with 1.2.4.1?
> > >
> > > Craig
> >
> > Ooops, I forgot I still had an 1.2.4.1 installation here. Exactly the same
> > as in 1.2.5cvs. No issues with image and PDF export.
> 
> As I expected, thanks for testing.
> 
> Craig

Thanks for the work on this.

I have a bit more info. I either changed something related to PDF output or I was having a brain dead moment when previously testing this. The problem I'm now seeing is that PDF output is correct (respecting the resolution of my imported image). However, bitmap output (either JPEG or PNG) is downsampled to 72dpi regardless of what resolution I output at. The resulting bitmap is the right size in terms of number of pixels (e.g. an A4 size page outputs to ~2500x3500 pixels at 300 DPI) but all of the elements (bitmaps or text) are output as though they were 72dpi resulting in severe pixelation when viewing the image at 100% zoom.

Sorry for the previous misinformation. FYI, I'm using qt-3.3.4 and libart_lgpl-2.3.17 (if that makes a difference).

Joel


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