/// <summary>
/// Reads the specified scanline.
/// </summary>
/// <param name="scanline">The scanline.</param>
/// <param name="pixels">The pixels, where the colors should be stored in RGBA format.</param>
/// <param name="header">The header, which contains information about the png file, like
/// the width of the image and the height.</param>
public void ReadScanline(byte[] scanline, byte[] pixels, PngHeader header)
{
int offset = 0;
byte[] newScanline = scanline.ToArrayByBitsLength(header.BitDepth);
if (_useAlpha)
{
Array.Copy(newScanline, 0, pixels, _row * header.Width * 4, newScanline.Length);
}
else
{
for (int x = 0; x < newScanline.Length / 3; x++)
{
offset = (_row * header.Width + x) * 4;
pixels[offset + 0] = newScanline[x * 3];
pixels[offset + 1] = newScanline[x * 3 + 1];
pixels[offset + 2] = newScanline[x * 3 + 2];
pixels[offset + 3] = (byte)255;
}
}
_row++;
}
/// <summary>
/// Reads the specified scanline.
/// </summary>
/// <param name="scanline">The scanline.</param>
/// <param name="pixels">The pixels, where the colors should be stored in RGBA format.</param>
/// <param name="header">The header, which contains information about the png file, like
/// the width of the image and the height.</param>
public void ReadScanline(byte[] scanline, byte[] pixels, PngHeader header)
{
int offset = 0;
//byte[] newScanline = scanline.ToArrayByBitsLength(header.BitDepth);
byte[] newScanline = IEnum.ToArrayByBitsLength(scanline, header.BitDepth);
if (_useAlpha)
{
for (int x = 0; x < header.Width / 2; x++)
{
offset = (_row * header.Width + x) * 4;
pixels[offset + 0] = newScanline[x * 2];
pixels[offset + 1] = newScanline[x * 2];
pixels[offset + 2] = newScanline[x * 2];
pixels[offset + 3] = newScanline[x * 2 + 1];
}
}
else
{
for (int x = 0; x < header.Width; x++)
{
offset = (_row * header.Width + x) * 4;
pixels[offset + 0] = newScanline[x];
pixels[offset + 1] = newScanline[x];
pixels[offset + 2] = newScanline[x];
pixels[offset + 3] = (byte)255;
}
}
_row++;
}
/// <summary>
/// Reads the specified scanline.
/// </summary>
/// <param name="scanline">The scanline.</param>
/// <param name="pixels">The pixels, where the colors should be stored in RGBA format.</param>
/// <param name="header">The header, which contains information about the png file, like
/// the width of the image and the height.</param>
public void ReadScanline(byte[] scanline, byte[] pixels, PngHeader header)
{
byte[] newScanline = scanline.ToArrayByBitsLength(header.BitDepth);
int offset = 0, index = 0;
if (_paletteAlpha != null && _paletteAlpha.Length > 0)
{
// If the alpha palette is not null and does one or
// more entries, this means, that the image contains and alpha
// channel and we should try to read it.
for (int i = 0; i < header.Width; i++)
{
index = newScanline[i];
offset = (_row * header.Width + i) * 4;
pixels[offset + 0] = _palette[index * 3];
pixels[offset + 1] = _palette[index * 3 + 1];
pixels[offset + 2] = _palette[index * 3 + 2];
pixels[offset + 3] = _paletteAlpha.Length > index ? _paletteAlpha[index] : (byte)255;
}
}
else
{
for (int i = 0; i < header.Width; i++)
{
index = newScanline[i];
offset = (_row * header.Width + i) * 4;
pixels[offset + 0] = _palette[index * 3];
pixels[offset + 1] = _palette[index * 3 + 1];
pixels[offset + 2] = _palette[index * 3 + 2];
pixels[offset + 3] = (byte)255;
}
}
_row++;
}
private void ReadHeaderChunk(byte[] data)
{
_header = new PngHeader();
Array.Reverse(data, 0, 4);
Array.Reverse(data, 4, 4);
_header.Width = BitConverter.ToInt32(data, 0);
_header.Height = BitConverter.ToInt32(data, 4);
_header.BitDepth = data[8];
_header.ColorType = data[9];
_header.FilterMethod = data[11];
_header.InterlaceMethod = data[12];
_header.CompressionMethod = data[10];
}
private void WriteHeaderChunk(PngHeader header)
{
byte[] chunkData = new byte[13];
WriteInteger(chunkData, 0, header.Width);
WriteInteger(chunkData, 4, header.Height);
chunkData[8] = header.BitDepth;
chunkData[9] = header.ColorType;
chunkData[10] = header.CompressionMethod;
chunkData[11] = header.FilterMethod;
chunkData[12] = header.InterlaceMethod;
WriteChunk(PngChunkTypes.Header, chunkData);
}
/// <summary>
/// Encodes the data of the specified image and writes the result to
/// the specified stream.
/// </summary>
/// <param name="image">The image, where the data should be get from.
/// Cannot be null (Nothing in Visual Basic).</param>
/// <param name="stream">The stream, where the image data should be written to.
/// Cannot be null (Nothing in Visual Basic).</param>
/// <exception cref="ArgumentNullException">
/// <para><paramref name="image"/> is null (Nothing in Visual Basic).</para>
/// <para>- or -</para>
/// <para><paramref name="stream"/> is null (Nothing in Visual Basic).</para>
/// </exception>
public void Encode(ExtendedImage image, Stream stream)
{
Guard.NotNull(image, "image");
Guard.NotNull(stream, "stream");
_image = image;
_stream = stream;
// Write the png header.
stream.Write(
new byte[]
{
0x89, 0x50, 0x4E, 0x47,
0x0D, 0x0A, 0x1A, 0x0A
}, 0, 8);
PngHeader header = new PngHeader();
header.Width = image.PixelWidth;
header.Height = image.PixelHeight;
header.ColorType = 6;
header.BitDepth = 8;
header.FilterMethod = 0;
header.CompressionMethod = 0;
header.InterlaceMethod = 0;
WriteHeaderChunk(header);
WritePhysicsChunk();
WriteGammaChunk();
if (IsWritingUncompressed)
{
WriteDataChunksFast();
}
else
{
WriteDataChunks();
}
WriteEndChunk();
stream.Flush();
}
