////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()); } }