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Combine Multiple Images Into a Single PDF

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pdfsavewidget
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  • mrjjM mrjj

    @geor
    hi , have you tried to render it really large and then
    scale down to fit A4?

    georG Offline
    georG Offline
    geor
    wrote on last edited by
    #27

    @mrjj yep no matter how large the pixmap awlays appears very small on the pdf

    mrjjM 1 Reply Last reply
    0
    • georG geor

      @mrjj yep no matter how large the pixmap awlays appears very small on the pdf

      mrjjM Offline
      mrjjM Offline
      mrjj
      Lifetime Qt Champion
      wrote on last edited by
      #28

      @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 1 Reply Last reply
      2
      • 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
            0
            • 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
                0
                • 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
                    0
                    • 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 Offline
                          JonBJ Offline
                          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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