dcpixel.h

转化为DIB位图再显示出来的dicom文件C++代码

/*
 *
 *  Copyright (C) 1994-2005, OFFIS
 *
 *  This software and supporting documentation were developed by
 *
 *    Kuratorium OFFIS e.V.
 *    Healthcare Information and Communication Systems
 *    Escherweg 2
 *    D-26121 Oldenburg, Germany
 *
 *  THIS SOFTWARE IS MADE AVAILABLE,  AS IS,  AND OFFIS MAKES NO  WARRANTY
 *  REGARDING  THE  SOFTWARE,  ITS  PERFORMANCE,  ITS  MERCHANTABILITY  OR
 *  FITNESS FOR ANY PARTICULAR USE, FREEDOM FROM ANY COMPUTER DISEASES  OR
 *  ITS CONFORMITY TO ANY SPECIFICATION. THE ENTIRE RISK AS TO QUALITY AND
 *  PERFORMANCE OF THE SOFTWARE IS WITH THE USER.
 *
 *  Module:  dcmdata
 *
 *  Author:  Andreas Barth
 *
 *  Purpose: Interface of class DcmPixelData
 *
 *  Last Update:      $Author: meichel $
 *  Update Date:      $Date: 2005/12/08 16:28:30 $
 *  CVS/RCS Revision: $Revision: 1.28 $
 *  Status:           $State: Exp $
 *
 *  CVS/RCS Log at end of file
 *
 */

#ifndef DCPIXEL_H
#define DCPIXEL_H

#include "dcmtk/config/osconfig.h"    /* make sure OS specific configuration is included first */

#include "dcmtk/ofstd/ofconsol.h"
#include "dcmtk/dcmdata/dcvrpobw.h"
#include "dcmtk/ofstd/oflist.h"

class DcmCodec;
class DcmCodecList;
class DcmStack;
class DcmPixelSequence;
class DcmPixelData;
class DcmRepresentationEntry;


class DcmRepresentationParameter
{
public:
    /// default constructor
    DcmRepresentationParameter() {}

    /// copy constructor
    DcmRepresentationParameter(const DcmRepresentationParameter&) {}

    /// destructor
    virtual ~DcmRepresentationParameter() {}

    /** this methods creates a copy of type DcmRepresentationParameter *
     *  it must be overweritten in every subclass.
     *  @return copy of this object
     */
    virtual DcmRepresentationParameter *clone() const = 0;

    /** returns the class name as string.
     *  can be used in operator== as poor man's RTTI replacement.
     */
    virtual const char *className() const = 0;

    /** compares an object to another DcmRepresentationParameter.
     *  Implementation must make sure that classes are comparable.
     *  @param arg representation parameter to compare with
     *  @return true if equal, false otherwise.
     */
    virtual OFBool operator==(const DcmRepresentationParameter &arg) const = 0;
};


/** an object of this class maintains one compression "version"
 *  of a PixelData element within a DICOM dataset.  There can be
 *  multiple compressed versions in parallel, with different
 *  transfer syntaxes (compression algorithms) or representation
 *  parameters (e.g. compression factors).
 */
class DcmRepresentationEntry
{
    /** constructor
     *  @param rt transfer syntax
     *  @param rp pointer to representation parameter on heap,
     *     will be deleted when this object destructs.
     *  @param pixSeq pointer to pixel sequence on heap,
     *     will be deleted when this object destructs.
     */
    DcmRepresentationEntry(
        const E_TransferSyntax rt,
        const DcmRepresentationParameter * rp,
        DcmPixelSequence * pixSeq);

    /// copy constructor
    DcmRepresentationEntry(const DcmRepresentationEntry &oldEntry);

    /// destructor
    ~DcmRepresentationEntry();

    /// comparison operator
    OFBool operator==(const DcmRepresentationEntry& x) const;

    /// comparison operator
    OFBool operator!=(const DcmRepresentationEntry & x) const
    {
      return !(*this == x);
    }

private:
    /// private undefined copy assignment operator
    DcmRepresentationEntry &operator=(const DcmRepresentationEntry &);

    /// transfer syntax
    E_TransferSyntax repType;

    /// representation parameter for this pixel sequence
    DcmRepresentationParameter * repParam;

    /// the compressed pixel sequence itself
    DcmPixelSequence * pixSeq;

    friend class DcmPixelData;
};

typedef OFList<DcmRepresentationEntry *> DcmRepresentationList;
typedef OFListIterator(DcmRepresentationEntry *) DcmRepresentationListIterator;
typedef OFListConstIterator(DcmRepresentationEntry *) DcmRepresentationListConstIterator;

/** The class DcmPixelData stores different pixel representations identified by
 * a type (the transfer syntax) and some representation parameters
 * The three unencapsulated transfer syntaxes belong to the same pixel
 * representation.
 * A type (or transfer syntax) conforms to a representation if
 * the type and the representation type are equal or both are unencapsulated.
 * If this is valid for the representation read or set by chooseRepresentation
 * then this representation is the conforming representation.
 * else a representation with the default parameter set defined in the
 * codec is the conforming representation.
 */
class DcmPixelData : public DcmPolymorphOBOW
{
private:
    friend class DcmRepresentationEntry;

    /// List of representations of pixel data
    DcmRepresentationList repList;

    /// Iterator to the last dummy element in representation lis
    DcmRepresentationListIterator repListEnd;

    /// Iterator to the original representation. if an uncompressed
    /// representation is used the iterator points to repList.end()
    DcmRepresentationListIterator original;

    /// current list element for some operations
    DcmRepresentationListIterator current;

    /// shows if an unecapsulated representation is stored
    OFBool existUnencapsulated;

    /** this flag indicates that this pixel data element will be written
     *  in uncompressed (defined length) format even if the dataset
     *  itself is written in a compressed syntax where pixel data is normally
     *  written in encapsulated (undefined length) format.
     *  By default this flag is false, unless the dataset was read in an
     *  encapsulated transfer syntax and this pixel data element was already
     *  present in uncompressed format.
     */
    OFBool alwaysUnencapsulated;
    
    /// value representation of unencapsulated data
    DcmEVR unencapsulatedVR;

    /// in write function: pointer to current pixel sequence
    DcmPixelSequence * pixelSeqForWrite;

    /** This function removes all pixel representations from the list
     *  of pixel representations except the one which was passed. Note
     *  that if parameter leaveInList equals repListEnd, all representations
     *  will be removed from the list.
     *  @param leaveInList Iterator to a representation which shall not
     *                     be removed from the list of representations.
     */
    void clearRepresentationList(
        DcmRepresentationListIterator leaveInList);

    /** find a conforming representation in the list of
     *  encapsulated representations
     */
    OFCondition findConformingEncapsulatedRepresentation(
        const DcmXfer & repType,
        const DcmRepresentationParameter * repParam,
        DcmRepresentationListIterator & result);

    /** find a representation entry and return an iterator to the found entry
     *  or the next element in the list. The condition returned can be EC_Normal
     *  if such an entry is found or EC_RepresentationNotFound. The pixSeq
     *  attribute in findEntry can be NULL, it is not needed for the find
     *  operation!
     */
    OFCondition findRepresentationEntry(
        const DcmRepresentationEntry & findEntry,
        DcmRepresentationListIterator & result);

    /** insert or replace a representation entry in the list
     */
    DcmRepresentationListIterator insertRepresentationEntry(
        DcmRepresentationEntry * repEntry);

    /** decode representation to unencapsulated format
     */
    OFCondition decode(
        const DcmXfer & fromType,
        const DcmRepresentationParameter * fromParam,
        DcmPixelSequence * fromPixSeq,
        DcmStack & pixelStack);

    /** encode to encapsulated format
     */
    OFCondition encode(
        const DcmXfer & fromType,
        const DcmRepresentationParameter * fromParam,
        DcmPixelSequence * fromPixSeq,
        const DcmXfer & toType,
        const DcmRepresentationParameter *toParam,
        DcmStack & pixelStack);

    void recalcVR()
    {
        if (current == repList.end()) Tag.setVR(unencapsulatedVR);
        else Tag.setVR(EVR_OB);
    }

public:
    DcmPixelData(const DcmTag & tag, const Uint32 len = 0);
    DcmPixelData(const DcmPixelData & pixelData);
    virtual ~DcmPixelData();

    DcmPixelData &operator=(const DcmPixelData &obj);

    /** clone method
     *  @return deep copy of this object
     */
    virtual DcmObject *clone() const
    {
      return new DcmPixelData(*this);
    }

    virtual OFCondition setVR(DcmEVR vr);
    virtual DcmEVR ident() const { return EVR_PixelData; }

    virtual void print(ostream &out,
                       const size_t flags = 0,
                       const int level = 0,
                       const char *pixelFileName = NULL,
                       size_t *pixelCounter = NULL);

    /** tests if it is possible to write a specific representation
     *  Only existing representations are considered, since this
     *  method does not create a representation.
     */
    virtual OFBool canWriteXfer(const E_TransferSyntax newXfer,
                                const E_TransferSyntax oldXfer);

    /** returns length of representation conforming to the
     *  transfer syntax with tag, vr, ... It does not create a
     *  representation. If no conforming representation exists an
     *  error code is set and 0 returned.
     */
    virtual Uint32 calcElementLength(const E_TransferSyntax xfer,
                                     const E_EncodingType enctype);

    /** returns length of representation value field conforming to
     *  given transfer syntax. It does not create a representation.
     *  If no conforming representation exists, an error code is set
     *  and 0 returned.
     */
    virtual Uint32 getLength(
        const E_TransferSyntax xfer  = EXS_LittleEndianImplicit,
        const E_EncodingType enctype = EET_UndefinedLength);