libjpeg provides very detailed status codes, see http://libjpeg.cvs.sourceforge.net/v....h?view=markup. However, qjpeghandler.cpp does not seem to check them. The corresponding function is
Qt Code: 
  1. static bool read_jpeg_image(QIODevice *device, QImage *outImage, const QByteArray &parameters, QSize scaledSize, int inQuality )
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Also, it seems that the interface provided by QImageIOHandler would need to be extended to be able to forward additional "status messages" since currently the read() and canRead() methods only return boolean values.