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Combine Multiple Images Into a Single PDF

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pdfsavewidget
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  • mrjjM mrjj

    @geor
    well a screen is 72/96 DPI
    and a printer is 600/1200/2400 DPI
    so images do get really small.

    As far as I remember, QPdfWriter have some setting for pdf resolution.
    maybe it can produce better output.

    georG Offline
    georG Offline
    geor
    wrote on last edited by
    #29

    @mrjj yeah I saw that but unfortunately I am using qt 5.2.1

    mrjjM 1 Reply Last reply
    0
    • georG geor

      @mrjj yeah I saw that but unfortunately I am using qt 5.2.1

      mrjjM Offline
      mrjjM Offline
      mrjj
      Lifetime Qt Champion
      wrote on last edited by
      #30

      @geor
      maybe you could try to scale it before
      drawing it to pdf.
      the scale function can be adjusted to aim for quality
      http://doc.qt.io/qt-5/qpixmap.html#scaled
      with Qt::SmoothTransformation

      note. it returns the scaled pixmap not modify the original.
      so something like
      mypixmap = mypixmap.scaled(xx)

      georG 1 Reply Last reply
      1
      • mrjjM mrjj

        @geor
        maybe you could try to scale it before
        drawing it to pdf.
        the scale function can be adjusted to aim for quality
        http://doc.qt.io/qt-5/qpixmap.html#scaled
        with Qt::SmoothTransformation

        note. it returns the scaled pixmap not modify the original.
        so something like
        mypixmap = mypixmap.scaled(xx)

        georG Offline
        georG Offline
        geor
        wrote on last edited by
        #31

        @mrjj It is abit better but still low quality

        mrjjM 1 Reply Last reply
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        • georG geor

          @mrjj It is abit better but still low quality

          mrjjM Offline
          mrjjM Offline
          mrjj
          Lifetime Qt Champion
          wrote on last edited by
          #32

          @geor
          well it was worth a shot.
          I assume you play around with different scales?
          Have you tried huge image like 1920x1080 and scale it down?
          You are using http://doc.qt.io/qt-5/qpaintdevice.html#logicalDpiX
          to calc how much to scale it?

          I dont remember quality being so bad but i was using a fairly
          large resolution so the widget was not that small.

          georG 1 Reply Last reply
          0
          • mrjjM mrjj

            @geor
            well it was worth a shot.
            I assume you play around with different scales?
            Have you tried huge image like 1920x1080 and scale it down?
            You are using http://doc.qt.io/qt-5/qpaintdevice.html#logicalDpiX
            to calc how much to scale it?

            I dont remember quality being so bad but i was using a fairly
            large resolution so the widget was not that small.

            georG Offline
            georG Offline
            geor
            wrote on last edited by
            #33

            @mrjj yes I am using it the quality is not so good however if I save it into an image its gives me a good quality so it seems taking an image instead of a pixmap a lot better.
            just like this
            ui->myWidget->grab().save("image.png");
            but this make me save 5 usless Images and I could not find a way to just use it temporarly..

            mrjjM 1 Reply Last reply
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            • georG geor

              @mrjj yes I am using it the quality is not so good however if I save it into an image its gives me a good quality so it seems taking an image instead of a pixmap a lot better.
              just like this
              ui->myWidget->grab().save("image.png");
              but this make me save 5 usless Images and I could not find a way to just use it temporarly..

              mrjjM Offline
              mrjjM Offline
              mrjj
              Lifetime Qt Champion
              wrote on last edited by mrjj
              #34

              @geor
              Im not sure what grab() is.
              Does it return QImage?
              Im wondering if u could just draw this directly?
              No reason to save first.

              georG 1 Reply Last reply
              0
              • mrjjM mrjj

                @geor
                Im not sure what grab() is.
                Does it return QImage?
                Im wondering if u could just draw this directly?
                No reason to save first.

                georG Offline
                georG Offline
                geor
                wrote on last edited by
                #35

                @mrjj it returns a pixmap

                mrjjM 1 Reply Last reply
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                • georG geor

                  @mrjj it returns a pixmap

                  mrjjM Offline
                  mrjjM Offline
                  mrjj
                  Lifetime Qt Champion
                  wrote on last edited by mrjj
                  #36

                  @geor
                  have you tried to convert to qimage and draw it?
                  http://doc.qt.io/qt-4.8/qpixmap.html#toImage
                  Not sure why saving as png makes any difference.

                  1 Reply Last reply
                  1
                  • D Offline
                    D Offline
                    drich
                    wrote on last edited by
                    #37
                    This post is deleted!
                    1 Reply Last reply
                    0
                    • JonBJ Online
                      JonBJ Online
                      JonB
                      wrote on last edited by JonB
                      #38

                      @MarieBurgan
                      Thanks for the plug. I'm sure @geor will thank you for this tip, if he visits here now two years after he last posted... ;-)

                      1 Reply Last reply
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                      • Pl45m4P Pl45m4 referenced this topic on

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