/// <summary>
/// Decodes a RGBE formatted image into a plain floating-point image
/// </summary>
/// <param name="_Source">The source RGBE formatted image</param>
/// <param name="_bSourceIsXYZ">Tells if the source image is encoded as XYZE rather than RGBE</param>
/// <param name="_bTargetNeedsXYZ">Tells if the target needs to be in CIE XYZ space (true) or RGB (false)</param>
/// <param name="_ColorProfile">The color profile for the image</param>
/// <returns>A HDR image as floats</returns>
public static float4[,] DecodeRGBEImage( PF_RGBE[,] _Source, bool _bSourceIsXYZ, bool _bTargetNeedsXYZ, ColorProfile _ColorProfile )
{
if ( _Source == null )
return null;
float4[,] Result = new float4[_Source.GetLength( 0 ), _Source.GetLength( 1 )];
DecodeRGBEImage( _Source, _bSourceIsXYZ, Result, _bTargetNeedsXYZ, _ColorProfile );
return Result;
}
/// <summary>
/// Decodes a RGBE formatted image into a plain floating-point image
/// </summary>
/// <param name="_Source">The source RGBE formatted image</param>
/// <param name="_bSourceIsXYZ">Tells if the source image is encoded as XYZE rather than RGBE</param>
/// <param name="_Target">The target float4 image</param>
/// <param name="_bTargetNeedsXYZ">Tells if the target needs to be in CIE XYZ space (true) or RGB (false)</param>
/// <param name="_ColorProfile">The color profile for the image</param>
public static void DecodeRGBEImage( PF_RGBE[,] _Source, bool _bSourceIsXYZ, float4[,] _Target, bool _bTargetNeedsXYZ, ColorProfile _ColorProfile )
{
if ( _bSourceIsXYZ ^ _bTargetNeedsXYZ )
{ // Requires conversion...
if ( _bSourceIsXYZ )
{ // Convert from XYZ to RGB
for ( int Y=0; Y < _Source.GetLength( 1 ); Y++ )
for ( int X=0; X < _Source.GetLength( 0 ); X++ )
_Target[X,Y] = _ColorProfile.XYZ2RGB( new float4( _Source[X,Y].DecodedColor.x, _Source[X,Y].DecodedColor.y, _Source[X,Y].DecodedColor.z, 1.0f ) );
}
else
{ // Convert from RGB to XYZ
for ( int Y=0; Y < _Source.GetLength( 1 ); Y++ )
for ( int X=0; X < _Source.GetLength( 0 ); X++ )
_Target[X,Y] = _ColorProfile.RGB2XYZ( new float4( _Source[X,Y].DecodedColor.x, _Source[X,Y].DecodedColor.y, _Source[X,Y].DecodedColor.z, 1.0f ) );
}
return;
}
// Simply decode vector and leave as-is
for ( int Y=0; Y < _Source.GetLength( 1 ); Y++ )
for ( int X=0; X < _Source.GetLength( 0 ); X++ )
_Target[X,Y] = new float4( _Source[X,Y].DecodedColor.x, _Source[X,Y].DecodedColor.y, _Source[X,Y].DecodedColor.z, 1.0f );
}
/// <summary>
/// Loads a bitmap in .HDR format into a RGBE array
/// </summary>
/// <param name="_HDRFormatBinary"></param>
/// <param name="_bIsXYZ">Tells if the image is encoded as XYZE rather than RGBE</param>
/// <param name="_ColorProfile">The color profile for the image</param>
/// <returns></returns>
public static unsafe PF_RGBE[,] LoadHDRFormat( byte[] _HDRFormatBinary, ColorProfile _ProfileOverride, out bool _bIsXYZ, out ColorProfile _ColorProfile )
{
try
{
// The header of a .HDR image file consists of lines terminated by '\n'
// It ends when there are 2 successive '\n' characters, then follows a single line containing the resolution of the image and only then, real scanlines begin...
//
// 1] We must isolate the header and find where it ends.
// To do this, we seek and replace every '\n' characters by '\0' (easier to read) until we find a double '\n'
List<string> HeaderLines = new List<string>();
int CharacterIndex = 0;
int LineStartCharacterIndex = 0;
while ( true )
{
if ( _HDRFormatBinary[CharacterIndex] == '\n' || _HDRFormatBinary[CharacterIndex] == '\0' )
{ // Found a new line!
_HDRFormatBinary[CharacterIndex] = 0;
fixed ( byte* pLineStart = &_HDRFormatBinary[LineStartCharacterIndex] )
HeaderLines.Add( new string( (sbyte*) pLineStart, 0, CharacterIndex-LineStartCharacterIndex, System.Text.Encoding.ASCII ) );
LineStartCharacterIndex = CharacterIndex + 1;
// Check for header end
if ( _HDRFormatBinary[CharacterIndex + 2] == '\n' )
{
CharacterIndex += 3;
break;
}
if ( _HDRFormatBinary[CharacterIndex + 1] == '\n' )
{
CharacterIndex += 2;
break;
}
}
// Next character
CharacterIndex++;
}
// 2] Read the last line containing the resolution of the image
byte* pScanlines = null;
string Resolution = null;
LineStartCharacterIndex = CharacterIndex;
while ( true )
{
if ( _HDRFormatBinary[CharacterIndex] == '\n' || _HDRFormatBinary[CharacterIndex] == '\0' )
{
_HDRFormatBinary[CharacterIndex] = 0;
fixed ( byte* pLineStart = &_HDRFormatBinary[LineStartCharacterIndex] )
Resolution = new string( (sbyte*) pLineStart, 0, CharacterIndex-LineStartCharacterIndex, System.Text.Encoding.ASCII );
fixed ( byte* pScanlinesStart = &_HDRFormatBinary[CharacterIndex + 1] )
pScanlines = pScanlinesStart;
break;
}
// Next character
CharacterIndex++;
}
// 3] Check format and retrieve resolution
// 3.1] Search lines for "#?RADIANCE" or "#?RGBE"
if ( RadianceFileFindInHeader( HeaderLines, "#?RADIANCE" ) == null && RadianceFileFindInHeader( HeaderLines, "#?RGBE" ) == null )
throw new NotSupportedException( "Unknown HDR format!" ); // Unknown HDR file format!
// 3.2] Search lines for format
string FileFormat = RadianceFileFindInHeader( HeaderLines, "FORMAT=" );
if ( FileFormat == null )
throw new Exception( "No format description!" ); // Couldn't get FORMAT
_bIsXYZ = false;
if ( FileFormat.IndexOf( "32-bit_rle_rgbe" ) == -1 )
{ // Check for XYZ encoding
_bIsXYZ = true;
if ( FileFormat.IndexOf( "32-bit_rle_xyze" ) == -1 )
throw new Exception( "Can't read format \"" + FileFormat + "\". Only 32-bit-rle-rgbe or 32-bit_rle_xyze is currently supported!" );
}
// 3.3] Search lines for the exposure
float fExposure = 0.0f;
string ExposureText = RadianceFileFindInHeader( HeaderLines, "EXPOSURE=" );
if ( ExposureText != null )
float.TryParse( ExposureText, out fExposure );
// 3.4] Read the color primaries
ColorProfile.Chromaticities Chromas = ColorProfile.Chromaticities.Radiance; // Default chromaticities
string PrimariesText = RadianceFileFindInHeader( HeaderLines, "PRIMARIES=" );
if ( PrimariesText != null )
{
string[] Primaries = PrimariesText.Split( ' ' );
if ( Primaries == null || Primaries.Length != 8 )
throw new Exception( "Failed to parse color profile chromaticities !" );
float.TryParse( Primaries[0], out Chromas.R.x );
float.TryParse( Primaries[1], out Chromas.R.y );
float.TryParse( Primaries[2], out Chromas.G.x );
float.TryParse( Primaries[3], out Chromas.G.y );
float.TryParse( Primaries[4], out Chromas.B.x );
float.TryParse( Primaries[5], out Chromas.B.y );
float.TryParse( Primaries[6], out Chromas.W.x );
float.TryParse( Primaries[7], out Chromas.W.y );
}
// 3.5] Create the color profile
if ( _ProfileOverride == null )
{
_ColorProfile = new ColorProfile( Chromas, ColorProfile.GAMMA_CURVE.STANDARD, 1.0f );
_ColorProfile.Exposure = fExposure;
}
else
_ColorProfile = _ProfileOverride;
// 3.6] Read the resolution out of the last line
int WayX = +1, WayY = +1;
int Width = 0, Height = 0;
int XIndex = Resolution.IndexOf( "+X" );
if ( XIndex == -1 )
{ // Wrong way!
WayX = -1;
XIndex = Resolution.IndexOf( "-X" );
}
if ( XIndex == -1 )
throw new Exception( "Couldn't find image width in resolution string \"" + Resolution + "\"!" );
int WidthEndCharacterIndex = Resolution.IndexOf( ' ', XIndex + 3 );
if ( WidthEndCharacterIndex == -1 )
WidthEndCharacterIndex = Resolution.Length;
Width = int.Parse( Resolution.Substring( XIndex + 2, WidthEndCharacterIndex - XIndex - 2 ) );
int YIndex = Resolution.IndexOf( "+Y" );
if ( YIndex == -1 )
{ // Flipped !
WayY = -1;
YIndex = Resolution.IndexOf( "-Y" );
}
if ( YIndex == -1 )
throw new Exception( "Couldn't find image height in resolution string \"" + Resolution + "\"!" );
int HeightEndCharacterIndex = Resolution.IndexOf( ' ', YIndex + 3 );
if ( HeightEndCharacterIndex == -1 )
HeightEndCharacterIndex = Resolution.Length;
Height = int.Parse( Resolution.Substring( YIndex + 2, HeightEndCharacterIndex - YIndex - 2 ) );
// The encoding of the image data is quite simple:
//
// _ Each floating-point component is first encoded in Greg Ward's packed-pixel format which encodes 3 floats into a single DWORD organized this way: RrrrrrrrGgggggggBbbbbbbbEeeeeeee (E being the common exponent)
// _ Each component of the packed-pixel is then encoded separately using a simple run-length encoding format
//
PF_RGBE[,] Dest = null;
if ( ms_ReadContent ) {
// 1] Allocate memory for the image and the temporary p_HDRFormatBinaryScanline
Dest = new PF_RGBE[Width, Height];
// 2] Read the scanlines
byte[,] TempScanline = new byte[Width,4];
int ImageY = WayY == +1 ? 0 : Height - 1;
for ( int y=0; y < Height; y++, ImageY += WayY )
{
if ( Width < 8 || Width > 0x7FFF || pScanlines[0] != 0x02 )
throw new Exception( "Unsupported old encoding format!" );
byte Temp;
byte Green, Blue;
// 2.1] Read an entire scanline
pScanlines++;
Green = *pScanlines++;
Blue = *pScanlines++;
Temp = *pScanlines++;
if ( Green != 2 || (Blue & 0x80) != 0 )
throw new Exception( "Unsupported old encoding format!" );
if ( ((Blue << 8) | Temp) != Width )
throw new Exception( "Line and image widths mismatch!" );
for ( int ComponentIndex=0; ComponentIndex < 4; ComponentIndex++ )
{
for ( int x=0; x < Width; )
{
byte Code = *pScanlines++;
if ( Code > 128 )
{ // Run-Length encoding
Code &= 0x7F;
byte RLValue = *pScanlines++;
while ( Code-- > 0 && x < Width )
TempScanline[x++,ComponentIndex] = RLValue;
}
else
{ // Normal encoding
while ( Code-- > 0 && x < Width )
TempScanline[x++, ComponentIndex] = *pScanlines++;
}
} // For every pixels of the scanline
} // For every color components (including exponent)
// 2.2] Post-process the scanline and re-order it correctly
int ImageX = WayX == +1 ? 0 : Width - 1;
for ( int x=0; x < Width; x++, ImageX += WayX )
{
Dest[x,y].R = TempScanline[ImageX, 0];
Dest[x,y].G = TempScanline[ImageX, 1];
Dest[x,y].B = TempScanline[ImageX, 2];
Dest[x,y].E = TempScanline[ImageX, 3];
}
}
}
return Dest;
}
catch ( Exception _e )
{ // Ouch!
throw new Exception( "An exception occured while attempting to load an HDR file!", _e );
}
}
