vsprintf() is ANSI so there is normally no need to test for it

[wxWidgets.git] / src / common / image.cpp

/////////////////////////////////////////////////////////////////////////////
// Name:        image.cpp
// Purpose:     wxImage
// Author:      Robert Roebling
// RCS-ID:      $Id$
// Copyright:   (c) Robert Roebling
// Licence:     wxWindows licence
/////////////////////////////////////////////////////////////////////////////

#ifdef __GNUG__
#pragma implementation "image.h"
#endif

// For compilers that support precompilation, includes "wx.h".
#include "wx/wxprec.h"

#ifdef __BORLANDC__
#pragma hdrstop
#endif

#include "wx/image.h"
#include "wx/debug.h"
#include "wx/log.h"
#include "../png/png.h"
#include "wx/filefn.h"

//-----------------------------------------------------------------------------
// wxImage
//-----------------------------------------------------------------------------

class wxImageRefData: public wxObjectRefData
{

public:
  wxImageRefData(void);
  ~wxImageRefData(void);
  
  int             m_width;
  int             m_height;
  unsigned char  *m_data;
  bool            m_hasMask;
  unsigned char   m_maskRed,m_maskGreen,m_maskBlue;
  bool            m_ok;
};

wxImageRefData::wxImageRefData(void)
{
    m_width = 0;
    m_height = 0;
    m_data = (unsigned char*) NULL;
    m_ok = FALSE;
    m_maskRed = 0;
    m_maskGreen = 0;
    m_maskBlue = 0;
    m_hasMask = FALSE;
}

wxImageRefData::~wxImageRefData(void)
{
    if (m_data) free( m_data );
}

wxList wxImage::sm_handlers;

//-----------------------------------------------------------------------------

#define M_IMGDATA ((wxImageRefData *)m_refData)

#if !USE_SHARED_LIBRARIES
IMPLEMENT_DYNAMIC_CLASS(wxImage, wxObject)
#endif

wxImage::wxImage()
{
}

wxImage::wxImage( int width, int height )
{
    Create( width, height );
}

wxImage::wxImage( const wxString& name, long type )
{
    LoadFile( name, type );
}

wxImage::wxImage( const wxImage& image )  
{  
    Ref(image); 
}

wxImage::wxImage( const wxImage* image )  
{ 
    if (image) Ref(*image); 
}

void wxImage::Create( int width, int height )
{
    m_refData = new wxImageRefData();
  
    M_IMGDATA->m_data = (unsigned char *) malloc( width*height*3 );
    if (M_IMGDATA->m_data)
    {
        for (int l = 0; l < width*height*3; l++) M_IMGDATA->m_data[l] = 0;
  
        M_IMGDATA->m_width = width;
        M_IMGDATA->m_height = height;
        M_IMGDATA->m_ok = TRUE;
    }
    else
    {
        UnRef();
    }
}

void wxImage::Destroy()
{
    UnRef();
}

bool wxImage::Ok() const 
{ 
    return (M_IMGDATA && M_IMGDATA->m_ok); 
}

char unsigned *wxImage::GetData() const
{
    if (!Ok()) return (char unsigned *)NULL;
  
    return M_IMGDATA->m_data;
}

void wxImage::SetData( char unsigned *WXUNUSED(data) )
{
}

void wxImage::SetMaskColour( unsigned char r, unsigned char g, unsigned char b )
{
    if (!Ok()) return;
  
    M_IMGDATA->m_maskRed = r;
    M_IMGDATA->m_maskGreen = g;
    M_IMGDATA->m_maskBlue = b;
    M_IMGDATA->m_hasMask = TRUE;
}

unsigned char wxImage::GetMaskRed() const
{
    if (!Ok()) return 0;
  
    return M_IMGDATA->m_maskRed;
}

unsigned char wxImage::GetMaskGreen() const
{
    if (!Ok()) return 0;
   
    return M_IMGDATA->m_maskGreen;
}

unsigned char wxImage::GetMaskBlue() const
{
    if (!Ok()) return 0;
  
    return M_IMGDATA->m_maskBlue;
}
  
void wxImage::SetMask( bool mask )
{
    if (!Ok()) return;
  
    M_IMGDATA->m_hasMask = mask;
}

bool wxImage::HasMask() const
{
    if (!Ok()) return FALSE;
  
    return M_IMGDATA->m_hasMask;
}

int wxImage::GetWidth() const 
{ 
    return (M_IMGDATA ? M_IMGDATA->m_width : 0); 
}

int wxImage::GetHeight() const 
{ 
    return (M_IMGDATA ? M_IMGDATA->m_height : 0); 
}

bool wxImage::LoadFile( const wxString& filename, long type )
{
    UnRef();
  
    if (!wxFileExists(filename))
    {
        wxLogWarning( "Image file does not exist." );

        return FALSE;
    }

    m_refData = new wxImageRefData;

    wxImageHandler *handler = FindHandler(type);

    if (handler == NULL) 
    {
        wxLogWarning( "No image handler for type %d defined.", type );

        return FALSE;
    }

    return handler->LoadFile( this, filename );
}

bool wxImage::SaveFile( const wxString& filename, int type )
{
    wxImageHandler *handler = FindHandler(type);

    if (handler == NULL) 
    {
      wxLogWarning( "No image handler for type %d defined.", type );

      return FALSE;
    }

    return handler->SaveFile( this, filename );
}

void wxImage::AddHandler( wxImageHandler *handler )
{
    sm_handlers.Append( handler );
}

void wxImage::InsertHandler( wxImageHandler *handler )
{
    sm_handlers.Insert( handler );
}

bool wxImage::RemoveHandler( const wxString& name )
{
    wxImageHandler *handler = FindHandler(name);
    if (handler)
    {
        sm_handlers.DeleteObject(handler);
        return TRUE;
    }
    else
        return FALSE;
}

wxImageHandler *wxImage::FindHandler( const wxString& name )
{
    wxNode *node = sm_handlers.First();
    while (node)
    {
        wxImageHandler *handler = (wxImageHandler*)node->Data();
        if (handler->GetName() == name) return handler;
        node = node->Next();
    }
    return (wxImageHandler *)NULL;
}

wxImageHandler *wxImage::FindHandler( const wxString& extension, long bitmapType )
{
    wxNode *node = sm_handlers.First();
    while (node)
    {
        wxImageHandler *handler = (wxImageHandler*)node->Data();
        if ( handler->GetExtension() == extension &&
            (bitmapType == -1 || handler->GetType() == bitmapType) )
        return handler;
        node = node->Next();
    }
    return (wxImageHandler*)NULL;
}

wxImageHandler *wxImage::FindHandler( long bitmapType )
{
    wxNode *node = sm_handlers.First();
    while (node)
    {
        wxImageHandler *handler = (wxImageHandler *)node->Data();
        if (handler->GetType() == bitmapType) return handler;
        node = node->Next();
    }
    return NULL;
}

void wxImage::InitStandardHandlers()
{
    AddHandler( new wxBMPHandler );
    AddHandler( new wxPNGHandler );
}

void wxImage::CleanUpHandlers()
{
    wxNode *node = sm_handlers.First();
    while (node)
    {
        wxImageHandler *handler = (wxImageHandler *)node->Data();
        wxNode *next = node->Next();
        delete handler;
        delete node;
        node = next;
    }
}

//-----------------------------------------------------------------------------
// wxImageHandler
//-----------------------------------------------------------------------------

#if !USE_SHARED_LIBRARIES
IMPLEMENT_DYNAMIC_CLASS(wxImageHandler,wxObject)
#endif

bool wxImageHandler::LoadFile( wxImage *WXUNUSED(image), const wxString& WXUNUSED(name) )
{
    return FALSE;
}

bool wxImageHandler::SaveFile( wxImage *WXUNUSED(image), const wxString& WXUNUSED(name) )
{
    return FALSE;
}

//-----------------------------------------------------------------------------
// wxPNGHandler
//-----------------------------------------------------------------------------

#if !USE_SHARED_LIBRARIES
IMPLEMENT_DYNAMIC_CLASS(wxPNGHandler,wxImageHandler)
#endif
  
bool wxPNGHandler::LoadFile( wxImage *image, const wxString& name )
{
   FILE               *f;
   png_structp         png_ptr;
   png_infop           info_ptr;
   unsigned char      *ptr, **lines, *ptr2;
   int                 transp,bit_depth,color_type,interlace_type;
   png_uint_32         width, height;
   unsigned int	       i;

   image->Destroy();
   
   transp = 0;
   png_ptr = png_create_read_struct( PNG_LIBPNG_VER_STRING, NULL, NULL, NULL );
   if (!png_ptr) return FALSE;

   info_ptr = png_create_info_struct( png_ptr );
   if (!info_ptr)
   {
     png_destroy_read_struct( &png_ptr, NULL, NULL );
     return FALSE;
   }

   if (setjmp(png_ptr->jmpbuf))
   {
     png_destroy_read_struct( &png_ptr, &info_ptr, NULL );
     return FALSE;
   }

   if (info_ptr->color_type == PNG_COLOR_TYPE_RGB_ALPHA)
   {
     png_destroy_read_struct( &png_ptr, &info_ptr, NULL );
     return FALSE;
   }
   
   f = fopen( name, "rb" );
   png_init_io( png_ptr, f );
   
   png_read_info( png_ptr, info_ptr );
   png_get_IHDR( png_ptr, info_ptr, &width, &height, &bit_depth, &color_type, &interlace_type, NULL, NULL );
   
   if (color_type == PNG_COLOR_TYPE_PALETTE) png_set_expand( png_ptr );
   
   png_set_strip_16( png_ptr );
   png_set_packing( png_ptr );
   if (png_get_valid( png_ptr, info_ptr, PNG_INFO_tRNS)) png_set_expand( png_ptr );
   png_set_filler( png_ptr, 0xff, PNG_FILLER_AFTER );
   
   image->Create( width, height );
   
   if (!image->Ok())
   {
     png_destroy_read_struct( &png_ptr, &info_ptr, NULL );
     return FALSE;
   }
   
   lines = (unsigned char **)malloc( height * sizeof(unsigned char *) );
   if (lines == NULL)
   {
     image->Destroy();
     png_destroy_read_struct( &png_ptr, &info_ptr, NULL );
     return FALSE;
   }
   
   for (i = 0; i < height; i++)
   {
     if ((lines[i] = (unsigned char *)malloc(width * (sizeof(unsigned char) * 4))) == NULL)
     {
       image->Destroy();
       for (unsigned int n = 0; n < i; n++) free( lines[n] );
       free( lines );
       png_destroy_read_struct( &png_ptr, &info_ptr, NULL );
       return FALSE;
     }
  }
     
   png_read_image( png_ptr, lines );
   png_destroy_read_struct( &png_ptr, &info_ptr, NULL );
   ptr = image->GetData();
   if ((color_type == PNG_COLOR_TYPE_GRAY) ||
       (color_type == PNG_COLOR_TYPE_GRAY_ALPHA))
     {
	for (unsigned int y = 0; y < height; y++)
	  {
	     ptr2 = lines[y];
	     for (unsigned int x = 0; x < width; x++)
	       {
		  unsigned char r = *ptr2++;
		  unsigned char a = *ptr2++;
		  if (a < 128)
		    {
		       *ptr++ = 255;
		       *ptr++ = 0;
		       *ptr++ = 255;
		       transp = 1;
		    }
		  else
		    {
		       *ptr++ = r;
		       *ptr++ = r;
		       *ptr++ = r;
		    }
	       }
	  }
     }
   else
     {
	for (unsigned int y = 0; y < height; y++)
	  {
	     ptr2 = lines[y];
	     for (unsigned int x = 0; x < width; x++)
	       {
		  unsigned char r = *ptr2++;
		  unsigned char g = *ptr2++;
		  unsigned char b = *ptr2++;
		  unsigned char a = *ptr2++;
		  if (a < 128)
		    {
		       *ptr++ = 255;
		       *ptr++ = 0;
		       *ptr++ = 255;
		       transp = 1;
		    }
		  else
		    {
		       if ((r == 255) && (g == 0) && (b == 255)) r = 254;
		       *ptr++ = r;
		       *ptr++ = g;
		       *ptr++ = b;
		    }
	       }
	  }
     }
   for (i = 0; i < height; i++) free( lines[i] );
   free( lines );
   if (transp)
     image->SetMaskColour( 255, 0, 255 );
   else
     image->SetMask( FALSE );
   
   return TRUE;
}


bool wxPNGHandler::SaveFile( wxImage *image, const wxString& name )
{
  FILE *f = fopen( name, "wb" );
  if (f)
  {
    png_structp png_ptr = png_create_write_struct( PNG_LIBPNG_VER_STRING, NULL, NULL, NULL);
    if (!png_ptr) 
    { 
      fclose( f ); 
      return FALSE; 
    }
    
    png_infop info_ptr = png_create_info_struct(png_ptr);
    if (info_ptr == NULL)
    {
      fclose(f);
      png_destroy_write_struct( &png_ptr, (png_infopp)NULL );
      return FALSE;
    }
    
    if (setjmp(png_ptr->jmpbuf))
    {
      fclose( f );
      png_destroy_write_struct( &png_ptr, (png_infopp)NULL );
      return FALSE;
    }
    
    png_init_io( png_ptr, f );
    png_set_IHDR( png_ptr, info_ptr, image->GetWidth(), image->GetHeight(), 8,
		  PNG_COLOR_TYPE_RGB_ALPHA, PNG_INTERLACE_NONE,
		  PNG_COMPRESSION_TYPE_BASE, PNG_FILTER_TYPE_BASE);
			  
    png_color_8 sig_bit;
    sig_bit.red = 8;
    sig_bit.green = 8;
    sig_bit.blue = 8;
    sig_bit.alpha = 8;
    png_set_sBIT( png_ptr, info_ptr, &sig_bit );
    png_write_info( png_ptr, info_ptr );
    png_set_shift( png_ptr, &sig_bit );
    png_set_packing( png_ptr );
    
    unsigned char *data = (unsigned char *)malloc( image->GetWidth()*4 );
    if (!data)
    {
      fclose( f );
      png_destroy_write_struct( &png_ptr, (png_infopp)NULL );
      return FALSE;
    }
    
    for (int y = 0; y < image->GetHeight(); y++)
    {
      unsigned char *ptr = image->GetData() + (y * image->GetWidth() * 3);
      for (int x = 0; x < image->GetWidth(); x++)
      {
	data[(x << 2) + 0] = *ptr++;
	data[(x << 2) + 1] = *ptr++;
	data[(x << 2) + 2] = *ptr++;
	if ((data[(x << 2) + 0] == image->GetMaskRed()) &&
	    (data[(x << 2) + 1] == image->GetMaskGreen()) &&
	    (data[(x << 2) + 2] == image->GetMaskBlue()))
          data[(x << 2) + 3] = 0;
	else
	  data[(x << 2) + 3] = 255;
      }
      png_bytep row_ptr = data;
      png_write_rows( png_ptr, &row_ptr, 1 );
    }
    free(data);
    png_write_end( png_ptr, info_ptr );
    png_destroy_write_struct( &png_ptr, (png_infopp)NULL );

    fclose(f);
  }
  return TRUE;
}

//-----------------------------------------------------------------------------
// wxBMPHandler
//-----------------------------------------------------------------------------

#if !USE_SHARED_LIBRARIES
IMPLEMENT_DYNAMIC_CLASS(wxBMPHandler,wxImageHandler)
#endif
  
bool wxBMPHandler::LoadFile( wxImage *image, const wxString& name )
{
   FILE               *file;
   unsigned char      *data, *ptr;
   int                 done, i, bpp, planes, comp, ncolors, line, column,
                       linesize, linepos, rshift = 0, gshift = 0, bshift = 0;
   unsigned char       byte;
   short int           word;
   long int            dbuf[4], dword, rmask = 0, gmask = 0, bmask = 0, offset,
                       size;
   signed char         bbuf[4];
   struct _cmap
     {
	unsigned char       r, g, b;
     }
                      *cmap = NULL;
#ifndef BI_RGB
#define BI_RGB       0
#define BI_RLE8      1
#define BI_RLE4      2
#define BI_BITFIELDS 3
#endif

  image->Destroy();

   file = fopen(name, "r");
   if (!file)
      return NULL;

   done = 0;
   /* 
    * Reading the bmp header 
    */

   fread(&bbuf, 1, 2, file);

   fread(dbuf, 4, 4, file);

   size = dbuf[0];
   offset = dbuf[2];

   fread(dbuf, 4, 2, file);
   int width = (int)dbuf[0];
   int height = (int)dbuf[1];
   if (width > 32767)
     {
	fprintf(stderr, "IMLIB ERROR: Image width > 32767 pixels for file\n");
	fclose(file);
	return FALSE;
     }
   if (height > 32767)
     {
	fprintf(stderr, "IMLIB ERROR: Image height > 32767 pixels for file\n");
	fclose(file);
	return FALSE;
     }
   fread(&word, 2, 1, file);
   planes = (int)word;
   fread(&word, 2, 1, file);
   bpp = (int)word;
   if (bpp != 1 && bpp != 4 && bpp != 8 && bpp && 16 && bpp != 24 && bpp != 32)
     {
	fprintf(stderr, "IMLIB ERROR: unknown bitdepth in file\n");
	fclose(file);
	return FALSE;
     }
   fread(dbuf, 4, 4, file);
   comp = (int)dbuf[0];
   if (comp != BI_RGB && comp != BI_RLE4 && comp != BI_RLE8 && comp != BI_BITFIELDS)
     {
	fprintf(stderr, "IMLIB ERROR: unknown encoding in Windows BMP file\n");
	fclose(file);
	return FALSE;
     }
   fread(dbuf, 4, 2, file);
   ncolors = (int)dbuf[0];
   if (ncolors == 0)
      ncolors = 1 << bpp;
   /* some more sanity checks */
   if (((comp == BI_RLE4) && (bpp != 4)) || ((comp == BI_RLE8) && (bpp != 8)) || ((comp == BI_BITFIELDS) && (bpp != 16 && bpp != 32)))
     {
	fprintf(stderr, "IMLIB ERROR: encoding of BMP doesn't match bitdepth\n");
	fclose(file);
	return FALSE;
     }
   if (bpp < 16)
     {
	cmap = (struct _cmap *)malloc(sizeof(struct _cmap) * ncolors);

	if (!cmap)
	  {
	     fprintf(stderr, "IMLIB ERROR: Cannot allocate RAM for color map in BMP file\n");
	     fclose(file);
	     return FALSE;
	  }
     }
   else
      cmap = NULL;
      
   image->Create( width, height );      
   ptr = image->GetData();
   if (!ptr)
     {
	fprintf(stderr, "IMLIB ERROR: Cannot allocate RAM for RGB data in file\n");
	fclose(file);
	if (cmap)
	   free(cmap);
	return FALSE;
     }

   /*
    * Reading the palette, if it exists.
    */
   if (bpp < 16 && ncolors != 0)
     {
	for (i = 0; i < ncolors; i++)
	  {
	     fread(bbuf, 1, 4, file);
	     cmap[i].b = bbuf[0];
	     cmap[i].g = bbuf[1];
	     cmap[i].r = bbuf[2];
	  }
     }
   else if (bpp == 16 || bpp == 32)
     {
	if (comp == BI_BITFIELDS)
	  {
	     int                 bit = 0;

	     fread(dbuf, 4, 3, file);
	     bmask = dbuf[0];
	     gmask = dbuf[1];
	     rmask = dbuf[2];
	     /* find shift amount.. ugly, but i can't think of a better way */
	     for (bit = 0; bit < bpp; bit++)
	       {
		  if (bmask & (1 << bit))
		     bshift = bit;
		  if (gmask & (1 << bit))
		     gshift = bit;
		  if (rmask & (1 << bit))
		     rshift = bit;
	       }
	  }
	else if (bpp == 16)
	  {
	     rmask = 0x7C00;
	     gmask = 0x03E0;
	     bmask = 0x001F;
	     rshift = 10;
	     gshift = 5;
	     bshift = 0;
	  }
	else if (bpp == 32)
	  {
	     rmask = 0x00FF0000;
	     gmask = 0x0000FF00;
	     bmask = 0x000000FF;
	     rshift = 16;
	     gshift = 8;
	     bshift = 0;
	  }
     }

   /*
    * REading the image data
    */
   fseek(file, offset, SEEK_SET);
   data = ptr;

   /* set the whole image to the background color */
   if (bpp < 16 && (comp == BI_RLE4 || comp == BI_RLE8))
     {
	for (i = 0; i < width * height; i++)
	  {
	     *ptr++ = cmap[0].r;
	     *ptr++ = cmap[0].g;
	     *ptr++ = cmap[0].b;
	  }
	ptr = data;
     }
   line = 0;
   column = 0;
#define poffset (line * width * 3 + column * 3)

   /*
    * BMPs are stored upside down... hmmmmmmmmmm....
    */

   linesize = ((width * bpp + 31) / 32) * 4;
   for (line = (height - 1); line >= 0; line--)
     {
	linepos = 0;
	for (column = 0; column < width;)
	  {
	     if (bpp < 16)
	       {
		  int                 index;

		  linepos++;
		  byte = getc(file);
		  if (bpp == 1)
		    {
		       int                 bit = 0;

		       for (bit = 0; bit < 8; bit++)
			 {
			    index = ((byte & (0x80 >> bit)) ? 1 : 0);
			    ptr[poffset] = cmap[index].r;
			    ptr[poffset + 1] = cmap[index].g;
			    ptr[poffset + 2] = cmap[index].b;
			    column++;
			 }
		    }
		  else if (bpp == 4)
		    {
		       if (comp == BI_RLE4)
			 {
			    fprintf(stderr, "can't deal with 4bit encoded yet.\n");
			    image->Destroy();
			    free(cmap);
			    return FALSE;
			 }
		       else
			 {
			    int                 nibble = 0;

			    for (nibble = 0; nibble < 2; nibble++)
			      {
				 index = ((byte & (0xF0 >> nibble * 4)) >> (!nibble * 4));
				 if (index >= 16)
				    index = 15;
				 ptr[poffset] = cmap[index].r;
				 ptr[poffset + 1] = cmap[index].g;
				 ptr[poffset + 2] = cmap[index].b;
				 column++;
			      }
			 }
		    }
		  else if (bpp == 8)
		    {
		       if (comp == BI_RLE8)
			 {
			    unsigned char       first;

			    first = byte;
			    byte = getc(file);
			    if (first == 0)
			      {
				 if (byte == 0)
				   {
/*                                    column = width; */
				   }
				 else if (byte == 1)
				   {
				      column = width;
				      line = -1;
				   }
				 else if (byte == 2)
				   {
				      byte = getc(file);
				      column += byte;
				      linepos = column * bpp / 8;
				      byte = getc(file);
				      line += byte;
				   }
				 else
				   {
				      int                 absolute = byte;

				      for (i = 0; i < absolute; i++)
					{
					   linepos++;
					   byte = getc(file);
					   ptr[poffset] = cmap[byte].r;
					   ptr[poffset + 1] = cmap[byte].g;
					   ptr[poffset + 2] = cmap[byte].b;
					   column++;
					}
				      if (absolute & 0x01)
					 byte = getc(file);
				   }
			      }
			    else
			      {
				 for (i = 0; i < first; i++)
				   {
				      ptr[poffset] = cmap[byte].r;
				      ptr[poffset + 1] = cmap[byte].g;
				      ptr[poffset + 2] = cmap[byte].b;
				      column++;
				      linepos++;
				   }
			      }
			 }
		       else
			 {
			    ptr[poffset] = cmap[byte].r;
			    ptr[poffset + 1] = cmap[byte].g;
			    ptr[poffset + 2] = cmap[byte].b;
			    column++;
			    linepos += size;
			 }
		    }
	       }
	     else if (bpp == 24)
	       {
		  linepos += fread(&bbuf, 1, 3, file);
		  ptr[poffset] = (unsigned char)bbuf[2];
		  ptr[poffset + 1] = (unsigned char)bbuf[1];
		  ptr[poffset + 2] = (unsigned char)bbuf[0];
		  column++;
	       }
	     else if (bpp == 16)
	       {
		  unsigned char       temp;

		  linepos += fread(&word, 2, 1, file);
		  temp = (word & rmask) >> rshift;
		  ptr[poffset] = temp;
		  temp = (word & gmask) >> gshift;
		  ptr[poffset + 1] = temp;
		  temp = (word & bmask) >> gshift;
		  ptr[poffset + 2] = temp;
		  column++;
	       }
	     else
	       {
		  unsigned char       temp;

		  linepos += fread(&dword, 4, 1, file);
		  temp = (dword & rmask) >> rshift;
		  ptr[poffset] = temp;
		  temp = (dword & gmask) >> gshift;
		  ptr[poffset + 1] = temp;
		  temp = (dword & bmask) >> bshift;
		  ptr[poffset + 2] = temp;
		  column++;
	       }
	  }
	while ((linepos < linesize) && (comp != 1) && (comp != 2))
	  {
	     int                 temp = fread(&byte, 1, 1, file);

	     linepos += temp;
	     if (!temp)
		break;
	  }
     }
   if (cmap) free(cmap);
      
   image->SetMask( FALSE );
   
   fclose(file);
   return TRUE;
}