c++ vtdcm对于压缩模式文档图片的读取

//获取dcm数据结构，一下图像数据仅针对单通道8字节数据
DcmFileFormat fileformat;
OFCondition oc = fileformat.loadFile(dcmPath.c_str()); //读取Dicom图像
if (!oc.good()) //判断Dicom文件是否读取成功
{
std::cout << "file Load error" << std::endl;
errorInfo = "file Load error";
return false;
}
DcmDataset* dataset = fileformat.getDataset();
E_TransferSyntax xfer = dataset->getOriginalXfer(); //得到传输语法

const char* transferSyntax = NULL;
fileformat.getMetaInfo()->findAndGetString(DCM_TransferSyntaxUID, transferSyntax); //获得传输语法字符串
string losslessTransUID = "1.2.840.10008.1.2.4.70";
string lossTransUID = "1.2.840.10008.1.2.4.51";
string losslessP14 = "1.2.840.10008.1.2.4.57";
string lossyP1 = "1.2.840.10008.1.2.4.50";
string lossyRLE = "1.2.840.10008.1.2.5";
if (transferSyntax == losslessTransUID || transferSyntax == lossTransUID || transferSyntax == losslessP14 || transferSyntax == lossyP1)
{
DJDecoderRegistration::registerCodecs();
dataset->chooseRepresentation(EXS_LittleEndianExplicit, NULL); //对压缩的图像像素进行解压
DJDecoderRegistration::cleanup();
}
else if (transferSyntax == lossyRLE)
{
DcmRLEDecoderRegistration::registerCodecs();
dataset->chooseRepresentation(EXS_LittleEndianExplicit, NULL);
DcmRLEDecoderRegistration::cleanup();
}
else
{
dataset->chooseRepresentation(xfer, NULL);
}

接下去有2种获取帧数据的方法：

1，直接按照索引去数据集数组中获取

DcmElement* element = NULL;
OFCondition result = dataset->findAndGetElement(DCM_PixelData, element); //获取图像数据
if (result.bad() || element == NULL)
return false;
Uint8* image_data = nullptr;
result = element->getUint8Array(image_data); //获取8位的图像数据

//fsIndex 需要获取的图片帧索引

cv::Mat dst(m_height, m_width, CV_8UC1, cv::Scalar::all(0));
unsigned char* data = nullptr;
for (int i = 0; i < m_height; i++)
{
data = dst.ptr<unsigned char>(i);
for (int j = 0; j < m_width; j++)
{
unsigned char pxData = (unsigned char)(image_data[i * m_width + j + fsIndex]);

}

2，转换成图片数据结构再获取每一个像素的值

unsigned short m_width; //获取图像的窗宽高
unsigned short m_height;
dataset->findAndGetUint16(DCM_Rows, m_height);
dataset->findAndGetUint16(DCM_Columns, m_width);

xfer = dataset->getCurrentXfer();　　　　 //得到新的传输语法，对于压缩格式的dcm文件读取很重要
DicomImage* m_dcmImage = new DicomImage((DcmObject*)dataset, xfer); //利用dataset生成DicomImage，需要上面的解压方法；

int framecount(m_dcmImage->getFrameCount()); //获取这个文件包含的图像的帧数
int nHeight = m_dcmImage->getHeight();
int nWidth = m_dcmImage->getWidth();
for (int k = 0; k < framecount; k++)
{
unsigned char* pixelData = (unsigned char*)(m_dcmImage->getOutputData(8, k, 0));
cv::Mat dst(nHeight, nWidth, CV_8UC1, cv::Scalar::all(0));
uchar* data = nullptr;

for (int i = 0; i < nHeight; i++)
{
data = dst.ptr<uchar>(i);
for (int j = 0; j < nWidth; j++)
{
data[j] = *(pixelData + i * nWidth + j);
}
}

}