////private static void WriteGamma(Stream outputStream)
////{
//// var gammaValue = (int)(parameters.Gamma * 100000f);
//// var chunkData = CreateChunk(gammaValue);
//// WriteChunk(outputStream, PngChunkTypeGamma, chunkData);
////}
private static void WriteDataChunks(Stream outputStream, WriteableBitmap writeableBitmap)
{
using (var chunkedStream = new ChunkedStream(MaximumChunkSize, data => WriteChunk(outputStream, PngChunkTypeData, data)))
{
using (var zlibStream = new ZlibStream(chunkedStream, CompressionMode.Compress, true))
{
var pixels = writeableBitmap.Pixels;
var width = writeableBitmap.PixelWidth;
var height = writeableBitmap.PixelHeight;
var index = 0;
var dataRowLength = width * 4;
var dataRow = new byte[dataRowLength];
for (var y = 0; y < height; y++)
{
zlibStream.WriteByte(0);
for (var x = 0; x < width; x++)
{
var color = pixels[index++];
var alpha = (byte)(color >> 24);
int alphaInt = alpha;
if (alphaInt == 0)
{
alphaInt = 1;
}
alphaInt = (255 << 8) / alphaInt;
var dataRowOffset = x * 4;
dataRow[dataRowOffset] = (byte)((((color >> 16) & 0xFF) * alphaInt) >> 8);
dataRow[dataRowOffset + 1] = (byte)((((color >> 8) & 0xFF) * alphaInt) >> 8);
dataRow[dataRowOffset + 2] = (byte)(((color & 0xFF) * alphaInt) >> 8);
dataRow[dataRowOffset + 3] = alpha;
}
zlibStream.Write(dataRow, 0, dataRowLength);
}
}
}
}
public static byte[] ZibDecompress(byte[] data)
{
var ms = new MemoryStream(data);
using (var msDecompressed = new System.IO.MemoryStream())
{
using (var zs = new ZlibStream(msDecompressed, CompressionMode.Decompress, true))
{
int readByte = ms.ReadByte();
while (readByte != -1)
{
zs.WriteByte((byte)readByte);
readByte = ms.ReadByte();
}
zs.Flush();
}
return(msDecompressed.ToArray());
}
}
