Jpeg2000 Class Reference

Wrapper around OpenJPEG library, in C, for opening jpeg2000 files. More...

#include <Jpeg2000.h>

Collaboration diagram for Jpeg2000:

Public Member Functions
	Jpeg2000 ()
	Single constructor. More...
bool	load (const QString &filename, QImage &image) const
	Load image from jpeg2000 file. More...
QStringList	supportedImageWildcards () const
	List the supported jpeg2000 file extensions, for filtering import files. More...

Detailed Description

Wrapper around OpenJPEG library, in C, for opening jpeg2000 files.

Definition at line 26 of file Jpeg2000.h.

Constructor & Destructor Documentation

Jpeg2000()

Jpeg2000::Jpeg2000

(

)

Single constructor.

Definition at line 21 of file Jpeg2000.cpp.

{
}

Member Function Documentation

load()

bool Jpeg2000::load	(	const QString &	filename,
		QImage &	image
	)		const

Load image from jpeg2000 file.

Definition at line 192 of file Jpeg2000.cpp.

{
  LOG4CPP_INFO_S ((*mainCat)) << "Jpeg2000::load"
                              << " filename=" << filename.toLatin1().data();

  if (invalidFileExtension (filename)) {
    return false;
  }

  opj_dparameters_t parameters;
  initializeParameters (parameters);

  parameters.decod_format = inputFormat (filename.toLatin1().data());

  opj_stream_t *inStream = opj_stream_create_default_file_stream (filename.toLatin1().data(), 1);
  if (!inStream) {
    LOG4CPP_ERROR_S ((*mainCat)) << "Jpeg2000::load encountered error opening stream";
    return false;
  }

  // Create decoder
  opj_codec_t *inCodec = decode (parameters.decod_format);
  if (!inCodec) {
    LOG4CPP_ERROR_S ((*mainCat)) << "Jpeg2000::load encountered error creating decoding stream";
    opj_stream_destroy (inStream);
    return false;
  }

  // Callbacks for local handling of errors
  opj_set_info_handler (inCodec, infoCallback, 0);
  opj_set_warning_handler (inCodec, warningCallback, 0);
  opj_set_error_handler (inCodec, errorCallback, 0);

  if (!opj_setup_decoder (inCodec,
                          &parameters)) {
    LOG4CPP_ERROR_S ((*mainCat)) << "Jpeg2000::load encountered error decoding stream";
    opj_stream_destroy (inStream);
    opj_destroy_codec (inCodec);
    return false;
  }

  // Read header and, if necessary, the JP2 boxes
  opj_image_t *image;
  if (!opj_read_header (inStream,
                        inCodec,
                        &image)) {
    LOG4CPP_ERROR_S ((*mainCat)) << "Jpeg2000::load encountered error reading header";
    opj_stream_destroy (inStream);
    opj_destroy_codec (inCodec);
    opj_image_destroy (image);
    return false;
  }

  // Get the decoded image
  if (!(opj_decode (inCodec,
                    inStream,
                    image) &&
       opj_end_decompress (inCodec,
                           inStream))) {
    LOG4CPP_ERROR_S ((*mainCat)) << "Jpeg2000::load failed to decode image";
    opj_destroy_codec (inCodec);
    opj_stream_destroy (inStream);
    opj_image_destroy (image);
    return false;
  }

  // Close the byte stream
  opj_stream_destroy (inStream);

  applyImageTweaks (image);

  // Transform into ppm image in memory
  bool success = true;
  QBuffer buffer;
  buffer.open (QBuffer::WriteOnly);
  if (imagetopnm (image,
                  buffer)) {
    LOG4CPP_ERROR_S ((*mainCat)) << "Jpeg2000::load failed to generate new image";
    success = false;

  } else {

    // Intermediate file for debugging
//    QFile file ("jpeg2000.ppm");
//    file.open (QIODevice::WriteOnly);
//    file.write (buffer.data());
//    file.close ();

    // Create output
    imageResult.loadFromData(buffer.data());

  }

  // Deallocate
  if (inCodec) {
    opj_destroy_codec (inCodec);
  }
  opj_image_destroy (image);

  return success;
}

supportedImageWildcards()

QStringList Jpeg2000::supportedImageWildcards

(

)

const

List the supported jpeg2000 file extensions, for filtering import files.

Definition at line 305 of file Jpeg2000.cpp.

{
  QStringList extensions = supportedFileExtensions();
  QStringList wildcards;

  QStringList::iterator itr;
  for (itr = extensions.begin(); itr != extensions.end(); itr++) {
    QString extension = *itr;
    QString wildcard = QString ("*.%1").arg (extension);
    wildcards << wildcard;
  }

  return wildcards;
}

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The documentation for this class was generated from the following files:

• Jpeg2000/Jpeg2000.h
• Jpeg2000/Jpeg2000.cpp