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Image plugin

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  • L LuGRU

    Hello,
    By that logic static version of Qt won't support jpeg / gif etc.
    Yes it's possible and supported, please do see doc: http://doc.qt.io/qt-5/plugins-howto.html#static-plugins

    S Offline
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    samdol
    wrote on last edited by
    #4

    @LuGRU
    In here
    It says
    Second, it is probably impossible to build a static version of Qt Creator because of the lack of support for plugins in a static environment.
    Does it mean that I cannot use plugin to support various image format?

    mrjjM 1 Reply Last reply
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    • S samdol

      @LuGRU
      In here
      It says
      Second, it is probably impossible to build a static version of Qt Creator because of the lack of support for plugins in a static environment.
      Does it mean that I cannot use plugin to support various image format?

      mrjjM Offline
      mrjjM Offline
      mrjj
      Lifetime Qt Champion
      wrote on last edited by
      #5

      @samdol
      No it means that Creator, the Qt IDE / Editor cannot be build as a static
      Qt application as it really needs to use dynamic loading.

      You can however create a new Image Plugin and static link with your application.
      But you cannot mix statically compiled Qt App and then use plugins dynamically.

      So you cannot have static Qt app and dynamic loading plugins.
      Meaning your STATIC linked App cannot at runtime load extra plugins.
      BUt you are free to link new ones in and that way support new formats.

      Can I ask what image format you want to add?

      Also if dynamic loading is important, why use static linking ?

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      • L Offline
        L Offline
        LuGRU
        wrote on last edited by LuGRU
        #6

        @samdol
        I think You did read this out of context, see:

        There are at least two reasons for not building static versions of the GUI tools. First, releasing a new version of an application is typically a task that you automate using a script and there is no need for GUI tools at this stage. Second, it is probably impossible to build a static version of Qt Creator because of the lack of support for plugins in a static environment. 
        

        This paragraph talks about QtCreator and it's plugins. QtCreator uses multiple "plugins", see QtCreator -> About Plugins page and I do suspect that this do refer to some of them (Device support ???).

        As I said before QImageIOPlugin do support static linkage. Case in point iOS. Deploying Qt app on iOS is statically linked and it do support images.

        PS. @mrjj replied while I was typing.

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        • mrjjM mrjj

          @samdol
          No it means that Creator, the Qt IDE / Editor cannot be build as a static
          Qt application as it really needs to use dynamic loading.

          You can however create a new Image Plugin and static link with your application.
          But you cannot mix statically compiled Qt App and then use plugins dynamically.

          So you cannot have static Qt app and dynamic loading plugins.
          Meaning your STATIC linked App cannot at runtime load extra plugins.
          BUt you are free to link new ones in and that way support new formats.

          Can I ask what image format you want to add?

          Also if dynamic loading is important, why use static linking ?

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          samdol
          wrote on last edited by
          #7

          @mrjj
          Thank you mrjj and LuGRU,
          It seems the static liking to Plugin is the way to go. Dynamic loading is not important.
          For now, I would like to support RAF CRW image formats.
          And enventually I need to support pcx, pnm, psd, rgb, eps and NEF formats.

          mrjjM 1 Reply Last reply
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          • S samdol

            @mrjj
            Thank you mrjj and LuGRU,
            It seems the static liking to Plugin is the way to go. Dynamic loading is not important.
            For now, I would like to support RAF CRW image formats.
            And enventually I need to support pcx, pnm, psd, rgb, eps and NEF formats.

            mrjjM Offline
            mrjjM Offline
            mrjj
            Lifetime Qt Champion
            wrote on last edited by
            #8

            @samdol
            Hi
            PSD itself is pretty hardcore. Maybe this can provide starting point
            https://github.com/Code-ReaQtor/libqpsd

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            • mrjjM mrjj

              @samdol
              Hi
              PSD itself is pretty hardcore. Maybe this can provide starting point
              https://github.com/Code-ReaQtor/libqpsd

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              samdol
              wrote on last edited by
              #9

              @mrjj
              Do I have to use plugin to show raw format image file?

              mrjjM 1 Reply Last reply
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              • S samdol

                @mrjj
                Do I have to use plugin to show raw format image file?

                mrjjM Offline
                mrjjM Offline
                mrjj
                Lifetime Qt Champion
                wrote on last edited by
                #10

                @samdol
                Hi do you mean a raw image format like in cameras or just raw as in no header etc?
                http://stackoverflow.com/questions/18637721/how-to-display-a-raw-image-file-in-a-qt-gui

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                • mrjjM mrjj

                  @samdol
                  Hi do you mean a raw image format like in cameras or just raw as in no header etc?
                  http://stackoverflow.com/questions/18637721/how-to-display-a-raw-image-file-in-a-qt-gui

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                  samdol
                  wrote on last edited by samdol
                  #11
                  This post is deleted!
                  1 Reply Last reply
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                  • mrjjM mrjj

                    @samdol
                    Hi do you mean a raw image format like in cameras or just raw as in no header etc?
                    http://stackoverflow.com/questions/18637721/how-to-display-a-raw-image-file-in-a-qt-gui

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                    samdol
                    wrote on last edited by
                    #12

                    @mrjj
                    I mean the image format like in cameras, such as CRW, NEF,...

                    mrjjM 1 Reply Last reply
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                    • S samdol

                      @mrjj
                      I mean the image format like in cameras, such as CRW, NEF,...

                      mrjjM Offline
                      mrjjM Offline
                      mrjj
                      Lifetime Qt Champion
                      wrote on last edited by
                      #13

                      @samdol said in Image plugin:

                      CRW

                      Nope, never saw such plugin. For some camera vendors you have to use the SDK to read it.
                      http://amin-ahmadi.com/2016/06/09/how-to-handle-canon-eos-raw-images-in-qt-c/

                      Alternatively, you can use a lib
                      http://www.libraw.org/
                      and use to convert to format that you can
                      load or embed into Qt app so it can load native.

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                      • mrjjM mrjj

                        @samdol said in Image plugin:

                        CRW

                        Nope, never saw such plugin. For some camera vendors you have to use the SDK to read it.
                        http://amin-ahmadi.com/2016/06/09/how-to-handle-canon-eos-raw-images-in-qt-c/

                        Alternatively, you can use a lib
                        http://www.libraw.org/
                        and use to convert to format that you can
                        load or embed into Qt app so it can load native.

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                        samdol
                        wrote on last edited by
                        #14

                        @mrjj
                        Thank you for the link.
                        Is the libraw OK to be used on commercial project?
                        Do I have to buy the license to use in commercial project?

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                        • M Offline
                          M Offline
                          mchinand
                          wrote on last edited by
                          #15

                          See the licensing options for libraw here. If you adhere to the terms of one of these licenses you can probably use it in a commercial project.

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                          • mrjjM mrjj

                            @samdol
                            Hi do you mean a raw image format like in cameras or just raw as in no header etc?
                            http://stackoverflow.com/questions/18637721/how-to-display-a-raw-image-file-in-a-qt-gui

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                            samdol
                            wrote on last edited by
                            #16

                            @mrjj

                            From the link, it seems we need to know
                            width, height ,QImage::Format about the raw image file before read it.
                            Could we know those information before read it?

                            mrjjM 1 Reply Last reply
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                            • S samdol

                              @mrjj

                              From the link, it seems we need to know
                              width, height ,QImage::Format about the raw image file before read it.
                              Could we know those information before read it?

                              mrjjM Offline
                              mrjjM Offline
                              mrjj
                              Lifetime Qt Champion
                              wrote on last edited by
                              #17

                              @samdol said in Image plugin:

                              Could we know those information before read it?

                              Not really. That is why raw means many things.
                              One can guess about it if knowing color format/depth and the filesize but
                              ultimately it could be anything.

                              For Cameras the raw format means uncompressed. Each vendor might save raw differently and hence
                              its not easy to "just" read raw files.

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                              • mrjjM mrjj

                                @samdol said in Image plugin:

                                Could we know those information before read it?

                                Not really. That is why raw means many things.
                                One can guess about it if knowing color format/depth and the filesize but
                                ultimately it could be anything.

                                For Cameras the raw format means uncompressed. Each vendor might save raw differently and hence
                                its not easy to "just" read raw files.

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                                samdol
                                wrote on last edited by
                                #18

                                @mrjj
                                when tried the code in the link with some raw files (NiKON NEF, ..) I could only see unrecognizable dots on the screen. Is it because I did not put the right w, h and format?

                                mrjjM 1 Reply Last reply
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                                • S samdol

                                  @mrjj
                                  when tried the code in the link with some raw files (NiKON NEF, ..) I could only see unrecognizable dots on the screen. Is it because I did not put the right w, h and format?

                                  mrjjM Offline
                                  mrjjM Offline
                                  mrjj
                                  Lifetime Qt Champion
                                  wrote on last edited by
                                  #19

                                  @samdol
                                  Yes if you specify wrong parameters for the format it will look distorted.

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                                  • mrjjM mrjj

                                    @samdol
                                    Yes if you specify wrong parameters for the format it will look distorted.

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                                    samdol
                                    wrote on last edited by
                                    #20

                                    @mrjj
                                    I saw some image Viewer shows raw image file. I wonder how it could read raw image. Because in order to read it correctly, we need to know the w, h, format in advance and there is no way to know w,h, format.

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                                    • mrjjM Offline
                                      mrjjM Offline
                                      mrjj
                                      Lifetime Qt Champion
                                      wrote on last edited by
                                      #21

                                      Well most of the viewers use a library and hence knows vendor raw format and can guess
                                      at format otherwise. Many raw formats do have a header to give more info.
                                      So for camera raw means uncompressed and non filtered and not so much raw block of image data as it
                                      means in other contexts.

                                      1 Reply Last reply
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