DICOM將16位轉換爲8位

Question

大樹： 我深深地想要找到以下問題的解決方案： 我想將dicom文件的像素數據轉換爲文件BitsAllocated爲16位的8位（byte []）。不管它是灰度還是顏色，都可以使用它。 還我知道顏色的SimplePerPixel爲3

3Q !!!!

Answer 1

你不能簡單地把像素數據，並將其轉換爲8位（除非你確信所有的值已經由一個字節支持的範圍內）。 這是因爲您可能會改變重要數據：Dicom文件可能會以像素密度單位或Hounsfield單位存儲像素數據，並且修改這些值可能會搞砸事情。

可以將轉換應用於8位來表示數據，從所述模態VOI/LUT和表示VOI/LUT變換產生的值。

此example使用imebra庫使用演示數據獲取每個顏色通道圖像的8位，然後保存爲jpeg格式。 在顏色轉換和圖像分配中將顏色空間從YBR_FULL修改爲RGB，以獲得RGB圖像。

實施例（在情況下，鏈接的變化）：

/* 

Imebra 2011 build 2013-07-16_08-42-08 

Imebra: a C++ Dicom library 

Copyright (c) 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011, 2012, 2013 by Paolo Brandoli/Binarno s.p. 
All rights reserved. 

This program is free software; you can redistribute it and/or modify 
it under the terms of the GNU General Public License version 2 as published by 
the Free Software Foundation. 

This program is distributed in the hope that it will be useful, 
but WITHOUT ANY WARRANTY; without even the implied warranty of 
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 
GNU General Public License for more details. 

You should have received a copy of the GNU General Public License 
along with this program; if not, write to the Free Software 
Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA 

------------------- 

If you want to use Imebra commercially then you have to buy the commercial 
support available at http://imebra.com 

After you buy the commercial support then you can use Imebra according 
to the terms described in the Imebra Commercial License Version 1. 
A copy of the Imebra Commercial License Version 1 is available in the 
documentation pages. 

Imebra is available at http://imebra.com 

The author can be contacted by email at info@binarno.com or by mail at 
the following address: 
Paolo Brandoli 
Rakuseva 14 
1000 Ljubljana 
Slovenia 



*/ 

#include <iostream> 


#include "../../library/imebra/include/imebra.h" 
#include <sstream> 

#ifdef PUNTOEXE_WINDOWS 
#include <process.h> 
#else 
#include <spawn.h> 
#include <sys/wait.h> 
#endif 

#include <memory> 
#include <list> 

using namespace puntoexe; 
using namespace puntoexe::imebra; 

int findArgument(const char* argument, int argc, char* argv[]) 
{ 
    for(int scanArg(0); scanArg != argc; ++scanArg) 
    { 
      if(std::string(argv[scanArg]) == argument) 
      { 
        return scanArg; 
      } 
    } 
    return -1; 
} 



int main(int argc, char* argv[]) 
{ 
    std::wstring version(L"1.0.0.1"); 
    std::wcout << L"dicom2jpeg version " << version << std::endl; 

    try 
    { 

      if(argc < 3) 
      { 
       std::wcout << L"Usage: dicom2jpeg dicomFileName jpegFileName [-ffmpeg FFMPEGPATH FFMPEGOPT]" << std::endl; 
       std::wcout << "dicomFileName  = name of the dicom file" << std::endl; 
       std::wcout << "jpegFileName   = name of the final jpeg file" << std::endl; 
       std::wcout << "-ffmpeg FFMPEGPATH = launches FFMPEG after generating the jpeg images." << std::endl; 
       std::wcout << " FFMPEGPATH is the path to FFMPEG" << std::endl; 
       std::wcout << " FFMPEGOPT are the options for ffmpeg" << std::endl; 
       std::wcout << " The input images and the frame rate are added automatically to the options" << std::endl; 
       return 1; 
      } 

      // Separate the extension from the file name 
      std::string outputFileName(argv[2]); 
      std::string extension; 
      size_t dotPos(outputFileName.rfind('.')); 
      if(dotPos != outputFileName.npos) 
      { 
        extension = outputFileName.substr(dotPos); 
        outputFileName.erase(dotPos); 
      } 
      else 
      { 
        extension = ".jpg"; 
      } 

      // Check for the -ffmpeg flag 
      int ffmpegFlag(findArgument("-ffmpeg", argc, argv)); 
      size_t framesCount(0); 
      ptr<dataSet> loadedDataSet; 

      try 
      { 

       // Open the file containing the dicom dataset 
       ptr<puntoexe::stream> inputStream(new puntoexe::stream); 
       inputStream->openFile(argv[1], std::ios_base::in); 

       // Connect a stream reader to the dicom stream. Several stream reader 
       // can share the same stream 
       ptr<puntoexe::streamReader> reader(new streamReader(inputStream)); 

       // Get a codec factory and let it use the right codec to create a dataset 
       // from the input stream 
       ptr<codecs::codecFactory> codecsFactory(codecs::codecFactory::getCodecFactory()); 
       loadedDataSet = codecsFactory->load(reader, 2048); 


       // Get the first image. We use it in case there isn't any presentation VOI/LUT 
       // and we have to calculate the optimal one 
       ptr<image> dataSetImage(loadedDataSet->getImage(0)); 
       imbxUint32 width, height; 
       dataSetImage->getSize(&width, &height); 


       // Build the transforms chain 
       ptr<transforms::transformsChain> chain(new transforms::transformsChain); 

       ptr<transforms::modalityVOILUT> modalityVOILUT(new transforms::modalityVOILUT(loadedDataSet)); 
       chain->addTransform(modalityVOILUT); 

       ptr<transforms::colorTransforms::colorTransformsFactory> colorFactory(transforms::colorTransforms::colorTransformsFactory::getColorTransformsFactory()); 
       if(colorFactory->isMonochrome(dataSetImage->getColorSpace())) 
       { 
        // Convert to MONOCHROME2 if a modality transform is not present 
        if(modalityVOILUT->isEmpty()) 
        { 
         ptr<transforms::colorTransforms::colorTransform> monochromeColorTransform(colorFactory->getTransform(dataSetImage->getColorSpace(), L"MONOCHROME2")); 
         if(monochromeColorTransform != 0) 
         { 
          chain->addTransform(monochromeColorTransform); 
         } 
        } 

        ptr<transforms::VOILUT> presentationVOILUT(new transforms::VOILUT(loadedDataSet)); 
        imbxUint32 firstVOILUTID(presentationVOILUT->getVOILUTId(0)); 
        if(firstVOILUTID != 0) 
        { 
         presentationVOILUT->setVOILUT(firstVOILUTID); 
        } 
        else 
        { 
         // Run the transform on the first image 
         ptr<image> temporaryImage = chain->allocateOutputImage(dataSetImage, width, height); 
         chain->runTransform(dataSetImage, 0, 0, width, height, temporaryImage, 0, 0); 

         // Now find the optimal VOILUT 
         presentationVOILUT->applyOptimalVOI(temporaryImage, 0, 0, width, height); 
        } 
        chain->addTransform(presentationVOILUT); 
       } 

       std::wstring initialColorSpace; 
       if(chain->isEmpty()) 
       { 
        initialColorSpace = dataSetImage->getColorSpace(); 
       } 
       else 
       { 
        ptr<image> startImage(chain->allocateOutputImage(dataSetImage, 1, 1)); 
        initialColorSpace = startImage->getColorSpace(); 
       } 

       // Color transform to YCrCb 
       ptr<transforms::colorTransforms::colorTransform> colorTransform(colorFactory->getTransform(initialColorSpace, L"YBR_FULL")); 
       if(colorTransform != 0) 
       { 
        chain->addTransform((colorTransform)); 
       } 

       ptr<image> finalImage(new image); 
       finalImage->create(width, height, image::depthU8, L"YBR_FULL", 7); 

       // Scan through the frames 
       for(imbxUint32 frameNumber(0); ; ++frameNumber) 
       { 
        if(frameNumber != 0) 
        { 
         dataSetImage = loadedDataSet->getImage(frameNumber); 
        } 


        if(chain->isEmpty() && dataSetImage->getDepth() != finalImage->getDepth() && dataSetImage->getHighBit() != finalImage->getHighBit()) 
        { 
         chain->addTransform(new transforms::transformHighBit); 
        } 

        if(!chain->isEmpty()) 
        { 
         chain->runTransform(dataSetImage, 0, 0, width, height, finalImage, 0, 0); 
        } 
        else 
        { 
         finalImage = dataSetImage; 
        } 

        // Open a stream for the jpeg 
        const std::wstring jpegTransferSyntax(L"1.2.840.10008.1.2.4.50"); 
        std::ostringstream jpegFileName; 
        jpegFileName << outputFileName; 
        if(frameNumber != 0 || ffmpegFlag >= 0) 
        { 
          jpegFileName << "_" << frameNumber; 
        } 
        jpegFileName << extension; 
        ptr<puntoexe::stream> jpegStream(new puntoexe::stream); 
        jpegStream->openFile(jpegFileName.str(), std::ios_base::out | std::ios_base::trunc); 
        ptr<puntoexe::streamWriter> jpegWriter(new streamWriter(jpegStream)); 
        ptr<codecs::codec> outputCodec(codecsFactory->getCodec(jpegTransferSyntax)); 

        // Write the jpeg image to the stream 
        outputCodec->setImage(jpegWriter, finalImage, jpegTransferSyntax, codecs::codec::veryHigh, 
          "OB", 8, false, false, false, false); 

        ++framesCount; 
       } 

      } 
      catch(dataSetImageDoesntExist&) 
      { 
        // Ignore this exception. It is thrown when we reach the 
        // end of the images list 
        exceptionsManager::getMessage(); 
      } 

      // All the images have been generated. 
      // Should we launch FFMPEG? 
      if(ffmpegFlag >= 0 && framesCount != 0) 
      { 
        // List of arguments to be passed to ffmpeg 
        typedef std::list<std::string> tOptionsList; 
        tOptionsList options; 

        // The first argument is the application's name 
        options.push_back(argv[ffmpegFlag + 1]); 

        // Calculate the frames per second from the available tags 
        double framesPerSecond(0); 
        double frameTime(loadedDataSet->getDouble(0x0018, 0, 0x1063, 0)); 
        if(frameTime > 0.1) 
        { 
          framesPerSecond = 1000/frameTime; 
        } 
        if(framesPerSecond < 0.1) 
        { 
          framesPerSecond = loadedDataSet->getUnsignedLong(0x0018, 0x0, 0x0040, 0x0); 
        } 
        if(framesPerSecond < 0.1) 
        { 
          framesPerSecond = loadedDataSet->getUnsignedLong(0x0008, 0x0, 0x2144, 0x0); 
        } 

        // Add the ffmpeg argument for the frames per second 
        if(framesPerSecond > 0.1) 
        { 
          options.push_back("-r"); 
          std::ostringstream frameRate; 
          frameRate << framesPerSecond; 
          options.push_back(frameRate.str()); 
        } 

        // Add the ffmpeg argument for the input files 
        options.push_back("-i"); 
        options.push_back(outputFileName + "_%d" + extension); 

        // Add the ffmpeg argument for the number of frames 
        options.push_back("-dframes"); 
        std::ostringstream frameCount; 
        frameCount << (unsigned long)framesCount; 
        options.push_back(frameCount.str()); 

        // Add the arguments specified when dicom2jpeg was launched 
        for(int copyArguments(ffmpegFlag + 2); copyArguments < argc; ++copyArguments) 
        { 
          options.push_back(argv[copyArguments]); 
        } 

        // Build the arguments array 
        std::auto_ptr<const char*> ffArgv(new const char*[options.size() + 1]); 
        size_t insertPosition(0); 
        for(tOptionsList::iterator scanOptions(options.begin()); scanOptions != options.end(); ++scanOptions, ++insertPosition) 
        { 
          ffArgv.get()[insertPosition] = (*scanOptions).c_str(); 
        } 
        ffArgv.get()[options.size()] = 0; 

        // Launch ffmpeg 
#ifdef PUNTOEXE_WINDOWS 
     return (int)_spawnvp(_P_WAIT , argv[ffmpegFlag + 1], ffArgv.get()); 
#else 
     char *environment[] = {0}; 

     pid_t process_id; 
     posix_spawnp (&process_id, argv[ffmpegFlag + 1], 
         0, 0, (char* const*)ffArgv.get(), (char* const*)environment); 
     wait(0); 
#endif 

      } 

      return 0; 

    } 
    catch(...) 
    { 
      std::wcout << exceptionsManager::getMessage(); 
      return 1; 
    } 
} 

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