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    Requested png metadata support

    suggestion: support (read+write!) for png metadata

    Most importantly: the png comments (=text chunks: iTXt, tEXt, zTXt),
    but there are lots of other informative png tags ("chunks"). See http://www.libpng.org/pub/png/spec/1...-Contents.html





    For consistency reasons, the png metadata should be displayed by IV in the same way as the jpg metadata, i.e. by pressing the i key.
    Layoutwise, the infos should be presented similarly to jpg EXIF data - again: for consistency.


    5
    YES, I would appreciate this button. After all such buttons exist for JPG files, too.
    80.00%
    4
    NO, I would feel so disturbed by this button that I want other users to renounce it.
    20.00%
    1
    Last edited by boarder's paradise; 19.04.2011, 02:12 PM.

    #2
    I second this, it would be very useful

    Comment


      #3
      Nice idea!

      But up to now I did not know that the PNG format can contain such information!
      Indeed it would be not bad, if you could add an explaining text!
      For users of the PNG format it is a really interesting idea!
      But the most used picture format is the JPG format!
      That's why, a better suggestion would be: full support for jpg and png metadata

      (Unfortunately I use the PNG format extremely rarely!)
      Last edited by Frank; 02.01.2009, 02:55 PM. Reason: additions

      Comment


        #4
        Re: PNG Metadata Support

        I was only somewhat aware that the PNG format could contain 'that much data.' As a longtime user of iViewMedia Pro (now Microsoft Expression Media), I have often been annoyed at that application's one-sided 'handling' of this format with regard to PNG metadata, particularly IPTC captions, keywords, etc. It can read them in if they are present, but cannot write them to a PNG file if they are not. So I must say I'm a touch prejudiced: I hold that any app introducing PNG support for IPTC should have it go both ways (write as well as read).

        If you think that's asking too much of a pledgeware app, just take a moment to consider: were Irfan to implement PNG metadata support, he'd be a step ahead of Microsoft.

        BZT
        There's still room for two things in IrfanView: 1). Space at the bottom of each image in a full-screen slideshow to display such metadata as keywords, supplemental categories, origin etc.; 2). Space to add just those few (dozen) annoying metadata tags IrfanView can't read in, edit or save back to a file. I advocate both. BZT

        Comment


          #5
          +1 and here is some usefull stuff
          Imi este indiferent ce cred ceilalti despre mine, caci oricum fiecare crede ce-i convine lui si nu ceea ce e real,
          doar ca mi-ar fi placut sa ma vada asa cum sint de fapt, nu asa cum poate le-ar placea lor sa creada. Ei au ales deja...

          ··÷¦÷·· ·· · · · ·· ··÷¦÷·· ·· · · · ·· ··÷¦÷·· ·· · · · ·· ··÷¦÷·· ·· · · · ·· ··÷¦÷··
          ·· · ·M· · ·I· · ·D· · ·I· · ·· ·· ·M· · ·A· · ·N· · ·I· · ·A· · ·C· · ·S· · ··
          ··÷¦÷·· ·· · · · ·· ··÷¦÷·· ·· · · · ·· ··÷¦÷·· ·· · · · ·· ··÷¦÷·· ·· · · · ·· ··÷¦÷··

          Comment


            #6
            [EDIT: adding poll]


            --> crosslink to similar discussion I just found: http://en.irfanview-forum.de/vb/show...ry-information
            Last edited by boarder's paradise; 20.04.2011, 12:44 AM.

            Comment


              #7
              Originally posted by Jaff View Post
              +1 and here is some usefull stuff
              thank you

              Originally posted by Frank View Post
              [i]Nice idea! [...]
              But the most used picture format is the JPG format!
              with hdd space growing bigger and cheaper, lossless formats (including lossless image formats such as png) are gaining importance.

              And for non-photographic image content PNG compresses way better than JPG, which - let's not forget - reduces image quality and adds compression artefacts.

              Example: Wikipedia replaces all non-photographic JPEG images by PNG or SVG if available.

              Originally posted by Frank View Post
              That's why, a better suggestion would be: full support for jpg and png metadata
              jpg metadata (i.e. EXIF and IPTC) is already supported by IrfanView, isn't it?

              Originally posted by Silversleeves View Post
              I hold that any app introducing PNG support for IPTC should have it go both ways (write as well as read).
              Agreed. See OP.

              Originally posted by Silversleeves View Post
              just take a moment to consider: were Irfan to implement PNG metadata support, he'd be a step ahead of Microsoft.
              ... and ahead of lots of other image viewers, too, for that matter.
              Last edited by boarder's paradise; 19.04.2011, 03:22 PM.

              Comment


                #8
                Are there applications that put information chunks, especially text, into the png-images? Image editors, scanning software, engineering or other?

                Is there a (limited?) mapping between png-(text)-chunks and Exif?

                The major problem I see currently is that Exif data aren't carried over between RAW, JPG, TIF, etc. - Personally I'd put a solution to this way before starting on a new format.

                currently running 4.56 / 32 bit

                Comment


                  #9
                  Originally posted by jazzman View Post
                  Are there applications that put information chunks [...] into the png-images?
                  Yes. All chunks are "information chunks". All programs must be able to read+write the critical chunks (IHDR, PLTE, IDAT, IEND), otherwise they cannot save a valid png file.

                  Image editors/viewers which support color management also write ancillary chunks into the png file which define the color space (see first image above) that must be used to display the image (otherwise the image viewer shows wrong colors).


                  Originally posted by jazzman View Post
                  applications that put [...] especially text, into the png-images? Image editors, scanning software, engineering or other?
                  Yes. Many programs write their names into the png file upon saving.
                  E.g.:


                  Originally posted by jazzman View Post
                  Is there a (limited?) mapping between png-(text)-chunks and Exif?
                  No, two distinct animals. EXIF data consists of the camera settings (ISO speed, aperture value, shutter speed, etc.) stored by your digital camera at the moment of shooting a pic. As png is not predestined for photographic data and digital cameras usually don't save to png, there is no EXIF implementation for png (at least not that I know of). So mapping is only rudimentary at best, e.g. color profile can be saved in both EXIF and png metadata.

                  Originally posted by jazzman View Post
                  The major problem I see currently is that Exif data aren't carried over between RAW, JPG, TIF, etc. Personally I'd put a solution to this way before starting on a new format.
                  I second your motion for keeping EXIF data during RAW/JPEG conversions. However this has nothing to do with PNG because - again - png does not use photographic EXIF data.

                  Comment

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