mitkCompressedImageContainer.cpp

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/*============================================================================

The Medical Imaging Interaction Toolkit (MITK)

Copyright (c) German Cancer Research Center (DKFZ)
All rights reserved.

Use of this source code is governed by a 3-clause BSD license that can be
found in the LICENSE file.

============================================================================*/

#include "mitkCompressedImageContainer.h"
#include "mitkImageReadAccessor.h"

#include "itk_zlib.h"

#include <cstdlib>

mitk::CompressedImageContainer::CompressedImageContainer() : m_PixelType(nullptr), m_ImageGeometry(nullptr)
{
}

mitk::CompressedImageContainer::~CompressedImageContainer()
{
  for (auto iter = m_ByteBuffers.begin(); iter != m_ByteBuffers.end(); ++iter)
  {
    free(iter->first);
  }

  delete m_PixelType;
}

void mitk::CompressedImageContainer::SetImage(Image *image)
{
  for (auto iter = m_ByteBuffers.begin(); iter != m_ByteBuffers.end(); ++iter)
  {
    free(iter->first);
  }

  m_ByteBuffers.clear();

  // Compress diff image using zlib (will be restored on demand)
  // determine memory size occupied by voxel data
  m_ImageDimension = image->GetDimension();
  m_ImageDimensions.clear();

  m_PixelType = new mitk::PixelType(image->GetPixelType());

  m_OneTimeStepImageSizeInBytes = m_PixelType->GetSize(); // bits per element divided by 8
  for (unsigned int i = 0; i < m_ImageDimension; ++i)
  {
    unsigned int currentImageDimension = image->GetDimension(i);
    m_ImageDimensions.push_back(currentImageDimension);
    if (i < 3)
    {
      m_OneTimeStepImageSizeInBytes *= currentImageDimension; // only the 3D memory size
    }
  }

  m_ImageGeometry = image->GetGeometry();

  m_NumberOfTimeSteps = 1;
  if (m_ImageDimension > 3)
  {
    m_NumberOfTimeSteps = image->GetDimension(3);
  }

  for (unsigned int timestep = 0; timestep < m_NumberOfTimeSteps; ++timestep)
  {
    // allocate a buffer as specified by zlib
    unsigned long bufferSize =
      m_OneTimeStepImageSizeInBytes + static_cast<unsigned long>(m_OneTimeStepImageSizeInBytes * 0.2) + 12;
    auto *byteBuffer = (unsigned char *)malloc(bufferSize);

    if (itk::Object::GetDebug())
    {
      // compress image here into a buffer
      MITK_INFO << "Using ZLib version: '" << zlibVersion() << "'" << std::endl
                << "Attempting to compress " << m_OneTimeStepImageSizeInBytes << " image bytes into a buffer of size "
                << bufferSize << std::endl;
    }

    ImageReadAccessor imgAcc(image, image->GetVolumeData(timestep));
    ::Bytef *dest(byteBuffer);
    ::uLongf destLen(bufferSize);
    auto *source((unsigned char *)imgAcc.GetData());
    ::uLongf sourceLen(m_OneTimeStepImageSizeInBytes);
    int zlibRetVal = ::compress(dest, &destLen, source, sourceLen);
    if (itk::Object::GetDebug())
    {
      if (zlibRetVal == Z_OK)
      {
        MITK_INFO << "Success, using " << destLen << " bytes of the buffer (ratio "
                  << ((double)destLen / (double)sourceLen) << ")" << std::endl;
      }
      else
      {
        switch (zlibRetVal)
        {
          case Z_MEM_ERROR:
            MITK_ERROR << "not enough memory" << std::endl;
            break;
          case Z_BUF_ERROR:
            MITK_ERROR << "output buffer too small" << std::endl;
            break;
          default:
            MITK_ERROR << "other, unspecified error" << std::endl;
            break;
        }
      }
    }

    // only use the neccessary amount of memory, realloc the buffer!
    byteBuffer = (unsigned char *)realloc(byteBuffer, destLen);
    bufferSize = destLen;
    // MITK_INFO << "Using " << bufferSize << " bytes to store compressed image (" << destLen << " needed)" <<
    // std::endl;

    m_ByteBuffers.push_back(std::pair<unsigned char *, unsigned long>(byteBuffer, bufferSize));
  }
}

mitk::Image::Pointer mitk::CompressedImageContainer::GetImage()
{
  if (m_ByteBuffers.empty())
    return nullptr;

  // uncompress image data, create an Image
  Image::Pointer image = Image::New();
  unsigned int dims[20]; // more than 20 dimensions and bang
  for (unsigned int dim = 0; dim < m_ImageDimension; ++dim)
    dims[dim] = m_ImageDimensions[dim];

  image->Initialize(*m_PixelType, m_ImageDimension, dims); // this IS needed, right ?? But it does allocate memory ->
                                                           // does create one big lump of memory (also in windows)

  unsigned int timeStep(0);
  for (auto iter = m_ByteBuffers.begin(); iter != m_ByteBuffers.end(); ++iter, ++timeStep)
  {
    ImageReadAccessor imgAcc(image, image->GetVolumeData(timeStep));
    auto *dest((unsigned char *)imgAcc.GetData());
    ::uLongf destLen(m_OneTimeStepImageSizeInBytes);
    ::Bytef *source(iter->first);
    ::uLongf sourceLen(iter->second);
    int zlibRetVal = ::uncompress(dest, &destLen, source, sourceLen);
    if (itk::Object::GetDebug())
    {
      if (zlibRetVal == Z_OK)
      {
        MITK_INFO << "Success, destLen now " << destLen << " bytes" << std::endl;
      }
      else
      {
        switch (zlibRetVal)
        {
          case Z_DATA_ERROR:
            MITK_ERROR << "compressed data corrupted" << std::endl;
            break;
          case Z_MEM_ERROR:
            MITK_ERROR << "not enough memory" << std::endl;
            break;
          case Z_BUF_ERROR:
            MITK_ERROR << "output buffer too small" << std::endl;
            break;
          default:
            MITK_ERROR << "other, unspecified error" << std::endl;
            break;
        }
      }
    }
  }

  image->SetGeometry(m_ImageGeometry);
  image->Modified();

  return image;
}