public virtual DCMAbstractType Decode(byte[] data, ref uint idx)
{
MemoryStream ms = new MemoryStream();//创建流
ms.Write(data, 0, data.Length);
ms.Position = idx;
BinaryReader reader = new BinaryReader(ms);
DCMDataElement element = new DCMDataElement();
element.gtag = reader.ReadUInt16(); //组号
element.etag = reader.ReadUInt16(); //元素号
LookupDictionary(element);
element.length = reader.ReadUInt32(); //值长度
if (element.length == 0xffffffff) //undefined length
{
element.value = reader.ReadBytes((int)(reader.BaseStream.Length - reader.BaseStream.Position));
}
else
{
element.value = reader.ReadBytes((int)element.length);//获取值的内容
}
idx = (uint)ms.Position;
reader.Close(); //关闭内存流
ms.Close(); //关闭二进制读写
return(element);
}
public override List <DCMAbstractType> Decode(byte[] data, ref uint idx)
{
//打开filename文件，将文件内容读到缓冲区byte[] data
using (FileStream fs = File.OpenRead(filename))
{
data = new byte[fs.Length];
fs.Read(data, 0, (int)fs.Length);
}
//跳过128字节前导符(idx=128)，读取4字节的”DICM”
idx = 128;
//***
idx += 4;
//用ExplicitVRLittleEndian对象实例化filemeta对象，通过其Decode方法从data中读取头元素
syntax = new ExplicitVRLittleEndian();
filemeta = new DCMFileMeta(syntax);
filemeta.Decode(data, ref idx);
//读取(0002,0010)头元素即filemeta[DicomTags.TransferSyntaxUid]的值，
//在tsFactory中找到对应的数据集传输语法对象赋给基类的syntax字段
DCMDataElement synelem = (DCMDataElement)filemeta[DicomTags.TransferSyntaxUid];
syntax = tsFactory[synelem.ReadValue <String>()[0].Replace("\0", "")];
//调用base.Decode方法解码数据集
base.Decode(data, ref idx);
return(items);
}
public virtual DCMAbstractType Decode(byte[] data, ref uint idx)
{
DCMDataElement element = new DCMDataElement();
//读取TAG
element.gtag = vrdecoder.GetGroupTag(data, ref idx);
element.etag = vrdecoder.GetElementTag(data, ref idx);
//处理SQ
if (element.gtag == 0xfffe && element.etag == 0xe000) //处理SQ的三个特殊标记
{
DCMDataItem sqitem = new DCMDataItem(this);
uint length = vrdecoder.GetUInt(data, ref idx); //不能用GetLength
uint offset = idx;
while (idx - offset < length)
{
DCMAbstractType sqelem = Decode(data, ref idx); //递归
if (length == 0xffffffff && sqelem.gtag == 0xfffe && sqelem.etag == 0xe00d) //条目结束标记
{
break;
}
sqitem.items.Add(sqelem);
}
return(sqitem);
}
else if (element.gtag == 0xfffe && element.etag == 0xe0dd) //序列结束标记
{
element.vr = "UL";
element.length = vrdecoder.GetUInt(data, ref idx); //不能用GetLength
return(element);
}
//查数据字典得到VR,Name,VM
element.vr = vrdecoder.GetVR(data, ref idx);
DicomDictonaryEntry entry = dicomDictionary.GetEntry(element.gtag, element.etag);
if (entry != null)
{
if (element.vr == "")
{
element.vr = entry.Vr;
}
element.name = entry.Keyword;
element.vm = entry.Vm;
}
else if (element.vr == "" && element.etag == 0)
{
element.vr = "US";
}
//根据得到的值表示法构造VR子类对象
element.vrparser = vrfactory.GetVR(element.vr);
//读取值长度
element.length = element.vrparser.GetLength(data, ref idx);
//读取值
element.value = element.vrparser.GetValue(data, ref idx, element.length);
element.idx = idx;
return(element);
}
protected void LookupDictionary(DCMDataElement element)
{
//查数据字典得到VR,Name,VM
DicomDictionaryEntry entry = dictionary.GetEntry(element.gtag, element.etag);
if (entry != null)
{
if (element.vr == "" || element.vr == null)
{
element.vr = entry.VR;
}
element.name = entry.Name;
element.vm = entry.VM;
}
else if (element.vr == "" && element.etag == 0)
{
element.vr = "UL";
}
//得到VR对象实例
element.vrparser = vrfactory.GetVR(element.vr);
}
public override DCMAbstractType Decode(byte[] data, ref uint idx)
{
MemoryStream ms = new MemoryStream();//创建流
ms.Write(data, 0, data.Length);
ms.Position = idx;
BinaryReaderBE reader = new BinaryReaderBE(ms);
DCMDataElement element = new DCMDataElement();
element.gtag = reader.ReadUInt16(); //组号
element.etag = reader.ReadUInt16(); //元素号
LookupDictionary(element);
element.vr = Encoding.Default.GetString(reader.ReadBytes(2));
//判断OB, OW, OF, SQ, UT, UN
if (element.vr == "OB" || element.vr == "OW" || element.vr == "OF" || element.vr == "SQ" || element.vr == "UT" || element.vr == "UN")
{
ms.Position += 2; //跳过两字节0000H
element.length = reader.ReadUInt32(); //值长度
}
else
{
element.length = reader.ReadUInt16();//值长度
}
//element.value = reader.ReadBytes((int)element.length);//值的内容
if (element.length == 0xffffffff) //undefined length
{
element.value = reader.ReadBytes((int)(reader.BaseStream.Length - reader.BaseStream.Position));
}
else
{
element.value = reader.ReadBytes((int)element.length);
}
idx = (uint)ms.Position;
reader.Close(); //关闭内存流
ms.Close(); //关闭二进制读写
return(element);
}
public virtual DCMAbstractType Decode(byte[] data, ref uint idx)
{
DCMDataElement element = new DCMDataElement();
//读取TAG
element.gtag = vrdecoder.GetGroupTag(data, ref idx);
element.etag = vrdecoder.GetElementTag(data, ref idx);
//这一项仅仅只用于测试容易看出，Reference==0；
string tag = "(" + element.gtag.ToString("X4") + "," + element.etag.ToString("X4") + ")";
if (element.gtag == 0xfffe && element.etag == 0xe000)
{
DCMDataItem sqitem = new DCMDataItem(this);
sqitem.gtag = element.gtag;
sqitem.etag = element.etag;
uint length = vrdecoder.GetUInt32(data, ref idx);
sqitem.length = length;
uint offset = idx;
//idx小于value长度时,不断地调用Decode方法来解锁;
while (idx - offset < length)
{
//递归,不断地解码
//解出Tag不为DataElemt类型时,重复的递归
DCMAbstractType sqelem = Decode(data, ref idx);
if (sqelem.gtag == 0xfffe && sqelem.etag == 0xe00d)
{
break;
}
sqitem[0] = sqelem;
}
return(sqitem);
}
else if (element.gtag == 0xfffe && element.etag == 0xe00d) //序列结束标记
{
element.vr = "UL"; //回归初始状态
element.length = vrdecoder.GetUInt32(data, ref idx);
//不能用GetLength
//且不用解出Value
return(element);
}
else if (element.gtag == 0xfffe && element.etag == 0xe0dd)
{
element.vr = "UL";//回归初始状态
element.length = vrdecoder.GetUInt32(data, ref idx);
//不能用GetLength
//不用解出Value类了;
return(element);
}
//查数据字典得到VR,Name,VM
element.vr = vrdecoder.GetVR(data, ref idx);
//0002系类文件头并没有在DicomDirationay内有定义
DicomDictonaryEntry entry = dictionary.GetEntry(element.gtag, element.etag);
if (entry != null)
{
element.vr = entry.VR;
element.name = entry.Keyword;
element.vm = entry.VM;
}
else if (element.vr == "" && element.etag == 0)
{
element.vr = "US";
}
if (element.vr == "OB or OW")
{
//在上一层找items[DicomTags.BitsAllocated];但是上层对下层是完全不透明的;怎么办
element.vr = "OW";
}
try
{
vrdecoder = vrfactory.GetVR(element.vr);
element.vrparser = vrdecoder;
//读取值长度
element.length = vrdecoder.GetLength(data, ref idx, element.vr);
//读取值
element.value = vrdecoder.GetValue(data, ref idx, element.length);
return(element);
}
catch
{
throw;
}
}
