@ -267,45 +267,48 @@ namespace ImageSharp.Formats
/// <param name="source">The bytes to convert from. Cannot be null.</param>
/// <param name="bytesPerScanline">The number of bytes per scanline</param>
/// <param name="bits">The number of bits per value.</param>
/// <returns>The resulting <see cref="T:byte[] "/> array. Is never null.</returns>
/// <returns>The resulting <see cref="Span{Byte} "/> array. Is never null.</returns>
/// <exception cref="System.ArgumentNullException"><paramref name="source"/> is null.</exception>
/// <exception cref="System.ArgumentException"><paramref name="bits"/> is less than or equals than zero.</exception>
private static byte [ ] ToArrayByBitsLength ( byte [ ] source , int bytesPerScanline , int bits )
private static Span < byte > ToArrayByBitsLength ( Span < byte > source , int bytesPerScanline , int bits )
{
Guard . NotNull ( source , nameof ( source ) ) ;
Guard . MustBeGreaterThan ( bits , 0 , nameof ( bits ) ) ;
byte [ ] result ;
if ( bits < 8 )
if ( bits > = 8 )
{
result = new byte [ bytesPerScanline * 8 / bits ] ;
int mask = 0xFF > > ( 8 - bits ) ;
int resultOffset = 0 ;
return source ;
}
// ReSharper disable once ForCanBeConvertedToForeach
// First byte is the marker so skip.
for ( int i = 1 ; i < bytesPerScanline ; i + + )
byte [ ] result = new byte [ bytesPerScanline * 8 / bits ] ;
int mask = 0xFF > > ( 8 - bits ) ;
int resultOffset = 0 ;
for ( int i = 0 ; i < bytesPerScanline ; i + + )
{
byte b = source [ i ] ;
for ( int shift = 0 ; shift < 8 ; shift + = bits )
{
byte b = source [ i ] ;
for ( int shift = 0 ; shift < 8 ; shift + = bits )
{
int colorIndex = ( b > > ( 8 - bits - shift ) ) & mask ;
int colorIndex = ( b > > ( 8 - bits - shift ) ) & mask ;
result [ resultOffset ] = ( byte ) colorIndex ;
result [ resultOffset ] = ( byte ) colorIndex ;
resultOffset + + ;
}
resultOffset + + ;
}
}
else
{
result = source ;
}
return result ;
}
private static bool IsCriticalChunk ( PngChunk chunk )
{
return
chunk . Type = = PngChunkTypes . Header | |
chunk . Type = = PngChunkTypes . Palette | |
chunk . Type = = PngChunkTypes . Data | |
chunk . Type = = PngChunkTypes . End ;
}
/// <summary>
/// Reads the data chunk containing physical dimension data.
/// </summary>
@ -575,13 +578,15 @@ namespace ImageSharp.Formats
{
var color = default ( TPixel ) ;
Span < TPixel > rowSpan = pixels . GetRowSpan ( this . currentRow ) ;
// Trim the first marker byte from the buffer
var scanlineBuffer = new Span < byte > ( defilteredScanline , 1 ) ;
switch ( this . pngColorType )
{
case PngColorType . Grayscale :
int factor = 2 5 5 / ( ( int ) Math . Pow ( 2 , this . header . BitDepth ) - 1 ) ;
byte [ ] newScanline1 = ToArrayByBitsLength ( defilteredScanline , this . bytesPerScanline , this . header . BitDepth ) ;
Span < byte > newScanline1 = ToArrayByBitsLength ( scanlineBuffer , this . bytesPerScanline , this . header . BitDepth ) ;
for ( int x = 0 ; x < this . header . Width ; x + + )
{
byte intensity = ( byte ) ( newScanline1 [ x ] * factor ) ;
@ -595,10 +600,10 @@ namespace ImageSharp.Formats
for ( int x = 0 ; x < this . header . Width ; x + + )
{
int offset = 1 + ( x * this . bytesPerPixel ) ;
int offset = x * this . bytesPerPixel ;
byte intensity = defilteredScanline [ offset ] ;
byte alpha = defilteredScanline [ offset + this . bytesPerSample ] ;
byte intensity = scanlineBuffer [ offset ] ;
byte alpha = scanlineBuffer [ offset + this . bytesPerSample ] ;
color . PackFromRgba32 ( new Rgba32 ( intensity , intensity , intensity , alpha ) ) ;
rowSpan [ x ] = color ;
@ -608,7 +613,7 @@ namespace ImageSharp.Formats
case PngColorType . Palette :
this . ProcessScanlineFromPalette ( defilteredScanline , rowSpan ) ;
this . ProcessScanlineFromPalette ( scanlineBuffer , rowSpan ) ;
break ;
@ -673,10 +678,10 @@ namespace ImageSharp.Formats
/// <typeparam name="TPixel">The type of pixel we are expanding to</typeparam>
/// <param name="defilteredScanline">The scanline</param>
/// <param name="row">Thecurrent output image row</param>
private void ProcessScanlineFromPalette < TPixel > ( byte [ ] defilteredScanline , Span < TPixel > row )
private void ProcessScanlineFromPalette < TPixel > ( Span < byte > defilteredScanline , Span < TPixel > row )
where TPixel : struct , IPixel < TPixel >
{
byte [ ] newScanline = ToArrayByBitsLength ( defilteredScanline , this . bytesPerScanline , this . header . BitDepth ) ;
Span < byte > newScanline = ToArrayByBitsLength ( defilteredScanline , this . bytesPerScanline , this . header . BitDepth ) ;
byte [ ] pal = this . palette ;
var color = default ( TPixel ) ;
@ -688,19 +693,11 @@ namespace ImageSharp.Formats
// channel and we should try to read it.
for ( int x = 0 ; x < this . header . Width ; x + + )
{
int index = newScanline [ x + 1 ] ;
int index = newScanline [ x ] ;
int pixelOffset = index * 3 ;
rgba . A = this . paletteAlpha . Length > index ? this . paletteAlpha [ index ] : ( byte ) 2 5 5 ;
if ( rgba . A > 0 )
{
rgba . Rgb = pal . GetRgb24 ( pixelOffset ) ;
}
else
{
rgba = default ( Rgba32 ) ;
}
rgba . Rgb = pal . GetRgb24 ( pixelOffset ) ;
color . PackFromRgba32 ( rgba ) ;
row [ x ] = color ;
@ -712,7 +709,7 @@ namespace ImageSharp.Formats
for ( int x = 0 ; x < this . header . Width ; x + + )
{
int index = newScanline [ x + 1 ] ;
int index = newScanline [ x ] ;
int pixelOffset = index * 3 ;
rgba . Rgb = pal . GetRgb24 ( pixelOffset ) ;
@ -736,15 +733,15 @@ namespace ImageSharp.Formats
{
var color = default ( TPixel ) ;
// Trim the first marker byte from the buffer
var scanlineBuffer = new Span < byte > ( defilteredScanline , 1 ) ;
switch ( this . pngColorType )
{
case PngColorType . Grayscale :
int factor = 2 5 5 / ( ( int ) Math . Pow ( 2 , this . header . BitDepth ) - 1 ) ;
byte [ ] newScanline1 = ToArrayByBitsLength (
defilteredScanline ,
this . bytesPerScanline ,
this . header . BitDepth ) ;
for ( int x = pixelOffset , o = 1 ; x < this . header . Width ; x + = increment , o + + )
Span < byte > newScanline1 = ToArrayByBitsLength ( scanlineBuffer , this . bytesPerScanline , this . header . BitDepth ) ;
for ( int x = pixelOffset , o = 0 ; x < this . header . Width ; x + = increment , o + + )
{
byte intensity = ( byte ) ( newScanline1 [ o ] * factor ) ;
color . PackFromRgba32 ( new Rgba32 ( intensity , intensity , intensity ) ) ;
@ -755,10 +752,10 @@ namespace ImageSharp.Formats
case PngColorType . GrayscaleWithAlpha :
for ( int x = pixelOffset , o = 1 ; x < this . header . Width ; x + = increment , o + = this . bytesPerPixel )
for ( int x = pixelOffset , o = 0 ; x < this . header . Width ; x + = increment , o + = this . bytesPerPixel )
{
byte intensity = defilteredScanline [ o ] ;
byte alpha = defilteredScanline [ o + this . bytesPerSample ] ;
byte intensity = scanlineBuffer [ o ] ;
byte alpha = scanlineBuffer [ o + this . bytesPerSample ] ;
color . PackFromRgba32 ( new Rgba32 ( intensity , intensity , intensity , alpha ) ) ;
rowSpan [ x ] = color ;
}
@ -767,31 +764,20 @@ namespace ImageSharp.Formats
case PngColorType . Palette :
byte [ ] newScanline = ToArrayByBitsLength (
defilteredScanline ,
this . bytesPerScanline ,
this . header . BitDepth ) ;
Span < byte > newScanline = ToArrayByBitsLength ( scanlineBuffer , this . bytesPerScanline , this . header . BitDepth ) ;
var rgba = default ( Rgba32 ) ;
if ( this . paletteAlpha ! = null & & this . paletteAlpha . Length > 0 )
{
// If the alpha palette is not null and has one or more entries, this means, that the image contains an alpha
// channel and we should try to read it.
for ( int x = pixelOffset , o = 1 ; x < this . header . Width ; x + = increment , o + + )
for ( int x = pixelOffset , o = 0 ; x < this . header . Width ; x + = increment , o + + )
{
int index = newScanline [ o ] ;
int offset = index * 3 ;
rgba . A = this . paletteAlpha . Length > index ? this . paletteAlpha [ index ] : ( byte ) 2 5 5 ;
if ( rgba . A > 0 )
{
rgba . Rgb = this . palette . GetRgb24 ( offset ) ;
}
else
{
rgba = default ( Rgba32 ) ;
}
rgba . Rgb = this . palette . GetRgb24 ( offset ) ;
color . PackFromRgba32 ( rgba ) ;
rowSpan [ x ] = color ;
@ -801,7 +787,7 @@ namespace ImageSharp.Formats
{
rgba . A = 2 5 5 ;
for ( int x = pixelOffset , o = 1 ; x < this . header . Width ; x + = increment , o + + )
for ( int x = pixelOffset , o = 0 ; x < this . header . Width ; x + = increment , o + + )
{
int index = newScanline [ o ] ;
int offset = index * 3 ;
@ -825,14 +811,12 @@ namespace ImageSharp.Formats
using ( var compressed = new Buffer < byte > ( length ) )
{
// TODO: Should we use pack from vector here instead?
this . From16BitTo8Bit ( new Span < byte > ( defilteredScanline ) , compressed , length ) ;
for ( int x = pixelOffset , o = 1 ;
x < this . header . Width ;
x + = increment , o + = this . bytesPerPixel )
this . From16BitTo8Bit ( scanlineBuffer , compressed , length ) ;
for ( int x = pixelOffset , o = 0 ; x < this . header . Width ; x + = increment , o + = 3 )
{
rgba . R = compressed [ o ] ;
rgba . G = compressed [ o + this . bytesPerSample ] ;
rgba . B = compressed [ o + ( 2 * this . bytesPerSample ) ] ;
rgba . G = compressed [ o + 1 ] ;
rgba . B = compressed [ o + 2 ] ;
color . PackFromRgba32 ( rgba ) ;
rowSpan [ x ] = color ;
@ -841,11 +825,11 @@ namespace ImageSharp.Formats
}
else
{
for ( int x = pixelOffset , o = 1 ; x < this . header . Width ; x + = increment , o + = this . bytesPerPixel )
for ( int x = pixelOffset , o = 0 ; x < this . header . Width ; x + = increment , o + = this . bytesPerPixel )
{
rgba . R = defilteredScanline [ o ] ;
rgba . G = defilteredScanline [ o + this . bytesPerSample ] ;
rgba . B = defilteredScanline [ o + ( 2 * this . bytesPerSample ) ] ;
rgba . R = scanlineBuffer [ o ] ;
rgba . G = scanlineBuffer [ o + this . bytesPerSample ] ;
rgba . B = scanlineBuffer [ o + ( 2 * this . bytesPerSample ) ] ;
color . PackFromRgba32 ( rgba ) ;
rowSpan [ x ] = color ;
@ -862,13 +846,13 @@ namespace ImageSharp.Formats
using ( var compressed = new Buffer < byte > ( length ) )
{
// TODO: Should we use pack from vector here instead?
this . From16BitTo8Bit ( new Span < byte > ( defilteredScanline ) , compressed , length ) ;
for ( int x = pixelOffset , o = 1 ; x < this . header . Width ; x + = increment , o + = this . bytesPerPixel )
this . From16BitTo8Bit ( scanlineBuffer , compressed , length ) ;
for ( int x = pixelOffset , o = 0 ; x < this . header . Width ; x + = increment , o + = 4 )
{
rgba . R = compressed [ o ] ;
rgba . G = compressed [ o + this . bytesPerSample ] ;
rgba . B = compressed [ o + ( 2 * this . bytesPerSample ) ] ;
rgba . A = compressed [ o + ( 3 * this . bytesPerSample ) ] ;
rgba . G = compressed [ o + 1 ] ;
rgba . B = compressed [ o + 2 ] ;
rgba . A = compressed [ o + 3 ] ;
color . PackFromRgba32 ( rgba ) ;
rowSpan [ x ] = color ;
@ -877,12 +861,12 @@ namespace ImageSharp.Formats
}
else
{
for ( int x = pixelOffset , o = 1 ; x < this . header . Width ; x + = increment , o + = this . bytesPerPixel )
for ( int x = pixelOffset , o = 0 ; x < this . header . Width ; x + = increment , o + = this . bytesPerPixel )
{
rgba . R = defilteredScanline [ o ] ;
rgba . G = defilteredScanline [ o + this . bytesPerSample ] ;
rgba . B = defilteredScanline [ o + ( 2 * this . bytesPerSample ) ] ;
rgba . A = defilteredScanline [ o + ( 3 * this . bytesPerSample ) ] ;
rgba . R = scanlineBuffer [ o ] ;
rgba . G = scanlineBuffer [ o + this . bytesPerSample ] ;
rgba . B = scanlineBuffer [ o + ( 2 * this . bytesPerSample ) ] ;
rgba . A = scanlineBuffer [ o + ( 3 * this . bytesPerSample ) ] ;
color . PackFromRgba32 ( rgba ) ;
rowSpan [ x ] = color ;
@ -1025,9 +1009,9 @@ namespace ImageSharp.Formats
this . crc . Update ( this . chunkTypeBuffer ) ;
this . crc . Update ( chunk . Data , 0 , chunk . Length ) ;
if ( this . crc . Value ! = chunk . Crc )
if ( this . crc . Value ! = chunk . Crc & & IsCriticalChunk ( chunk ) )
{
throw new ImageFormatException ( "CRC Error. PNG Image chunk is corrupt!") ;
throw new ImageFormatException ( $"CRC Error. PNG {chunk.Type} chunk is corrupt!") ;
}
}
JimBobSquarePants
9 years ago
