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In which segment of a .jpeg stores QImageWriter the data?

  • Hi, I want to read via Javascript the data from a .jpeg file stored before with QImageWriter. How and in which segment are these data saved?

    I searched in the commend segment (FF FE COM Comments) but i could't find any data.


  • Lifetime Qt Champion

    what data? the compression settings etc ?
    to produce a valid jpg file, it must save the data as expected for the format.
    So you should be able to open it like any other jpeg file ?

  • @mrjj The QImageWriter was succesful because I read the data via QImageReader. The point is I have to read this data in a browser via Javascript. The data are arbitrary, currently only for testing.

  • Lifetime Qt Champion

    @PowerNow Can you please explain what data you mean? It is really unclear what you mean and what your use case is...

  • @jsulm: The data are arbitrary strings. E.g. I saved them with

    QImageWriter writer;
    writer.setText("key1", "Teststring1");
    writer.setText("key2", "Teststring2");

    In Qt everthing is fine!
    Is it possible that they are SEPERATELY saved under the commend segment (FF FE COM Comments)?

  • For who is interrested: The strings saved via QImageWriter are placed seperately in the commend section of a .jpeg as ascii characters.

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