dccodec.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 abstract class DcmCodec and the class DcmCodecStruct
 *
 *  Last Update:      $Author: meichel $
 *  Update Date:      $Date: 2005/12/09 14:48:14 $
 *  Source File:      $Source: /share/dicom/cvs-depot/dcmtk/dcmdata/include/dcmtk/dcmdata/dccodec.h,v $
 *  CVS/RCS Revision: $Revision: 1.18 $
 *  Status:           $State: Exp $
 *
 *  CVS/RCS Log at end of file
 *
 */

#ifndef DCCODEC_H
#define DCCODEC_H

#include "dcmtk/config/osconfig.h"    /* make sure OS specific configuration is included first */
#include "dcmtk/dcmdata/dctypes.h"
#include "dcmtk/dcmdata/dcerror.h"
#include "dcmtk/dcmdata/dcxfer.h"
#include "dcmtk/ofstd/oflist.h"

class DcmStack;
class DcmRepresentationParameter;
class DcmPixelSequence;
class DcmPolymorphOBOW;
class DcmItem;
class DcmTagKey;

/** abstract base class for a codec parameter object that
 *  describes the settings (modes of operations) for one
 *  particular codec (DcmCodec) object.
 */
class DcmCodecParameter
{
public:
    /// default constructor
    DcmCodecParameter() {}

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

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

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

};                    


/** abstract base class for a codec object that can be registered
 *  in dcmdata and performs transfer syntax transformation (i.e.
 *  compressing, decompressing or transcoding between different 
 *  compressed transfer syntaxes).
 *  When dcmdata is requested to write a transfer syntax that differs
 *  from the current one (i.e. the one in which the object was read),
 *  dcmdata dynamically searches for a DcmCodec object that is able
 *  to create the desired transfer syntax.  If no suitable codec
 *  is found, the write operation fails.
 */
class DcmCodec
{
public:
  /// default constructor
  DcmCodec() {}

  /// destructor
  virtual ~DcmCodec() {}

  /** decompresses the given pixel sequence and
   *  stores the result in the given uncompressedPixelData element.
   *  @param fromRepParam current representation parameter of compressed data, may be NULL
   *  @param pixSeq compressed pixel sequence
   *  @param uncompressedPixelData uncompressed pixel data stored in this element
   *  @param cp codec parameters for this codec
   *  @param objStack stack pointing to the location of the pixel data
   *    element in the current dataset.
   *  @return EC_Normal if successful, an error code otherwise.
   */
  virtual OFCondition decode(
      const DcmRepresentationParameter * fromRepParam,
      DcmPixelSequence * pixSeq,
      DcmPolymorphOBOW& uncompressedPixelData,
      const DcmCodecParameter * cp,
      const DcmStack& objStack) const = 0;

  /** compresses the given uncompressed DICOM image and stores
   *  the result in the given pixSeq element.
   *  @param pixelData pointer to the uncompressed image data in OW format
   *    and local byte order
   *  @param length of the pixel data field in bytes
   *  @param toRepParam representation parameter describing the desired
   *    compressed representation (e.g. JPEG quality)
   *  @param pixSeq compressed pixel sequence (pointer to new DcmPixelSequence object
   *    allocated on heap) returned in this parameter upon success.   
   *  @param cp codec parameters for this codec
   *  @param objStack stack pointing to the location of the pixel data
   *    element in the current dataset.
   *  @return EC_Normal if successful, an error code otherwise.
   */
  virtual OFCondition encode(
      const Uint16 * pixelData,
      const Uint32 length,
      const DcmRepresentationParameter * toRepParam,
      DcmPixelSequence * & pixSeq,
      const DcmCodecParameter *cp,
      DcmStack & objStack) const = 0;

  /** transcodes (re-compresses) the given compressed DICOM image and stores
   *  the result in the given toPixSeq element.
   *  @param fromRepType current transfer syntax of the compressed image
   *  @param fromRepParam current representation parameter of compressed data, may be NULL
   *  @param fromPixSeq compressed pixel sequence
   *  @param toRepParam representation parameter describing the desired
   *    new compressed representation (e.g. JPEG quality)
   *  @param toPixSeq compressed pixel sequence (pointer to new DcmPixelSequence object
   *    allocated on heap) returned in this parameter upon success.   
   *  @param cp codec parameters for this codec
   *  @param objStack stack pointing to the location of the pixel data
   *    element in the current dataset.
   *  @return EC_Normal if successful, an error code otherwise.
   */
  virtual OFCondition encode(
      const E_TransferSyntax fromRepType,
      const DcmRepresentationParameter * fromRepParam,
      DcmPixelSequence * fromPixSeq,
      const DcmRepresentationParameter * toRepParam,
      DcmPixelSequence * & toPixSeq,
      const DcmCodecParameter * cp,
      DcmStack & objStack) const = 0;

  /** checks if this codec is able to convert from the
   *  given current transfer syntax to the given new
   *  transfer syntax
   *  @param oldRepType current transfer syntax
   *  @param newRepType desired new transfer syntax
   *  @return true if transformation is supported by this codec, false otherwise.
   */
  virtual OFBool canChangeCoding(
      const E_TransferSyntax oldRepType,
      const E_TransferSyntax newRepType) const = 0;


  // static helper methods that have proven useful in codec classes derived from DcmCodec 

  /** helper function that inserts a string attribute with a given value into a dataset
   *  if missing in the dataset.
   *  @param dataset dataset to insert to, must not be NULL.
   *  @param tag tag key of attribute to check/insert
   *  @param val string value, may be NULL.
   *  @return EC_Normal if successful, an error code otherwise
   */   
  static OFCondition insertStringIfMissing(DcmItem *dataset, const DcmTagKey& tag, const char *val);

  /** helper function that converts a dataset containing a DICOM image
   *  into a valid (standard extended) Secondary Capture object
   *  by inserting all attributes that are type 1/2 in Secondary Capture
   *  and missing in the source dataset.  Replaces SOP Class UID
   *  by Secondary Capture. It does not, however, change an existing SOP Instance UID.
   *  @param dataset dataset to insert to, must not be NULL.
   *  @return EC_Normal if successful, an error code otherwise
   */   
  static OFCondition convertToSecondaryCapture(DcmItem *dataset);

  /** create new SOP instance UID and Source Image Sequence
   *  referencing the old SOP instance (if present)
   *  @param dataset dataset to be modified
   *  @param purposeOfReferenceCodingScheme coding scheme designator for purpose of reference code sequence
   *  @param purposeOfReferenceCodeValue code value for purpose of reference code sequence
   *  @param purposeOfReferenceCodeMeaning code meaning for purpose of reference code sequence
   *  @return EC_Normal if successful, an error code otherwise
   */
  static OFCondition newInstance(
    DcmItem *dataset, 
    const char *purposeOfReferenceCodingScheme = NULL,
    const char *purposeOfReferenceCodeValue = NULL,
    const char *purposeOfReferenceCodeMeaning = NULL);

  /** set first value of Image Type to DERIVED.
   *  @param dataset dataset to be modified
   *  @return EC_Normal if successful, an error code otherwise
   */
  static OFCondition updateImageType(DcmItem *dataset);

  /** insert code sequence into the given dataset
   *  @param dataset dataset to insert into
   *  @param tagKey tag of the code sequence
   *  @param codingSchemeDesignator coding scheme designator for the sequence item
   *  @param codeValue code value for the sequence item
   *  @param codeMeaning code meaning for the sequence item
   *  @return EC_Normal if successul, an error code otherwise
   */
  static OFCondition insertCodeSequence(
    DcmItem *dataset,
    const DcmTagKey &tagKey,
    const char *codingSchemeDesignator,
    const char *codeValue,
    const char *codeMeaning);

};


/** singleton that keeps list of registered codecs for dcmdata.
 *  All operations on the list are protected by a read/write lock
 *  and, therefore, are safe for multi-thread applications.
 */
class DcmCodecList
{

public:

  /// destructor
  virtual ~DcmCodecList();