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Resize Webp images

I had Converted Jpg to Webp But I want to resize the image.
using (Bitmap bitmap = new Bitmap(UploadName +jpgFileName))
{
using (var saveImageStream = System.IO.File.Open(webpFileName, FileMode.Create))
{
var encoder = new SimpleEncoder();
encoder.Encode(bitmap, saveImageStream, 90);
}
}

I think you can first resize in jpg then you convert from jpg to webp.
those methods i use to resize image:
You can recive a IFormFile jpgImage and convert to byte[] using method below:
public byte[] GetBytes(IFormFile formFile)
{
using var fileStream = formFile.OpenReadStream();
var bytes = new byte[formFile.Length];
fileStream.Read(bytes, 0, (int)formFile.Length);
return bytes;
}
// Methods to resize the jpg image in byte[]
using SixLabors.ImageSharp;
using SixLabors.ImageSharp.PixelFormats;
using SixLabors.ImageSharp.Processing;
...
public byte[] ResizeImage(byte[] img, int width, int height)
{
using var image = SixLabors.ImageSharp.Image.Load(img);
var options = new ResizeOptions
{
Size = new Size(width, height),
Mode = ResizeMode.Max
};
return Resize(image, options);
}
private byte[] Resize(Image<Rgba32> image, ResizeOptions resizeOptions)
{
byte[] ret;
image.Mutate(i => i.Resize(resizeOptions));
using MemoryStream ms = new MemoryStream();
image.SaveAsJpeg(ms);
ret = ms.ToArray();
ms.Close();
return ret;
}
After resize the jpg image in byte[] you convert to webp

'System.IO.InvalidDataException' In Stream.Read operation

I am compressing a json using deflate compression technique and saving to sql server database. The json contains values from any culture ie. th-TH, zh-TW. The compressed string is getting saved successfully in database.
Json includes data like {"#id":"2113","description":"อาหารเช้าคอนติเนนทัล"}
Now when i read the same data from db, i convert it to bytes as
Encoding encoding = Encoding.UTF8;
encoding.GetBytes(data ?? string.Empty)
The compression like this
public static string Compress(this string data, CompressionTypeOptions compressionType)
{
var bytes = Compress(Encoding.UTF-8.GetBytes(data ?? string.Empty), compressionType);
return Encoding.UTF-8.GetString(bytes);
}
}
private static byte[] Compress(byte[] data, CompressionTypeOptions compressionType)
{
using (var memoryStream1 = new MemoryStream(data))
{
using (var memoryStream2 = new MemoryStream())
{
using (var compressionStream = CreateCompressionStream(compressionType, (Stream)memoryStream2,
CompressionMode.Compress))
{
CopyTo((Stream)memoryStream1, compressionStream);
compressionStream.Close();
return memoryStream2.ToArray();
}
}
}
}
Then decompressing like this
using (var memoryStream = new MemoryStream(data))
{
using (var compressionStream = CreateCompressionStream(compressionType, (Stream)memoryStream,
CompressionMode.Decompress))
return ReadAllBytesFromStream(compressionStream);
}
Here is ReadAllBytesFromStream definition
private static byte[] ReadAllBytesFromStream(Stream stream)
{
using (var memoryStream = new MemoryStream())
{
var buffer1 = new byte[1];
while (true)
{
int count = stream.Read(buffer1, 0, 1);
if (count != 0)
memoryStream.Write(buffer1, 0, count);
else
break;
}
var length = memoryStream.Length;
var buffer2 = new byte[length];
memoryStream.Position = 0L;
memoryStream.Read(buffer2, 0, (int)length);
return buffer2;
}
}
Getting error at int count = stream.Read(buffer1, 0, 1); as
'System.IO.InvalidDataException'
'Unknown block type. Stream might be corrupted.'
Any help is appreaciated

Getting bigger size image while scaling C#

I am trying to scale the original image to 50% and 25% and try to download the scaled image in MVC. I am using the below code which was taken from Google search.
public byte[] ScaleImageByPercent(byte[] imageBuffer, int Percent)
{
using (Stream imageStream = new MemoryStream(imageBuffer))
{
using (Image scaleImage = Image.FromStream(imageStream))
{
float scalePercent = ((float)Percent / 100);
int originalWidth = scaleImage.Width;
int originalHeight = scaleImage.Height;
int originalXPoint = 0;
int originalYPoint = 0;
int scaleXPoint = 0;
int scaleYPoint = 0;
int scaleWidth = (int)(originalWidth * scalePercent);
int scaleHeight = (int)(originalHeight * scalePercent);
using (Bitmap scaleBitmapImage = new Bitmap(scaleWidth, scaleHeight, PixelFormat.Format24bppRgb))
{
scaleBitmapImage.SetResolution(scaleImage.HorizontalResolution, scaleImage.VerticalResolution);
Graphics graphicImage = Graphics.FromImage(scaleBitmapImage);
graphicImage.CompositingMode = CompositingMode.SourceCopy;
graphicImage.InterpolationMode = InterpolationMode.NearestNeighbor;
graphicImage.DrawImage(scaleImage,
new Rectangle(scaleXPoint, scaleYPoint, scaleWidth, scaleHeight),
new Rectangle(originalXPoint, originalYPoint, originalWidth, originalHeight),
GraphicsUnit.Pixel);
graphicImage.Dispose();
ImageConverter converter = new ImageConverter();
return (byte[])converter.ConvertTo(scaleBitmapImage, typeof(byte[]));
}
}
}
}
When i use 3.4MB image its returning 4.7MB in 50% and even worst in 100% its returning 18 MB.
EDIT:
After getting the byte array i am downloading the image using below code. After downloading while i check the file size in disk its showing bigger size.
HttpResponseMessage result = new HttpResponseMessage(HttpStatusCode.OK);
result.Content = new StreamContent(new MemoryStream(scaledBytes));
result.Content.Headers.ContentDisposition = new ContentDispositionHeaderValue("attachment");
result.Content.Headers.ContentType = new MediaTypeHeaderValue("application/octet-stream");
return result;
Am i doing the scaling correctly?. Which one i need to change get the lower size image while scaling using above functionality.

Your code works, I believe it's just a matter of image compression, basically you are pushing your byte array to your output stream as is, while you should save it as a jpeg. In my example I use a FileStream for simplicity, in your case you should use your output stream.
Give this a try (just drop any Jpg file on the compiled executable):
using System;
using System.Collections.Generic;
using System.Drawing;
using System.Drawing.Drawing2D;
using System.Drawing.Imaging;
using System.IO;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
namespace ConsoleApplication3
{
class Program
{
static void Main(string[] args)
{
string filePath = System.IO.Path.GetFullPath(args[0]);
byte[] originalImage = System.IO.File.ReadAllBytes(filePath);
byte[] resizedImage = ScaleImageByPercent(originalImage, 50);
using (Stream imageStream = new MemoryStream(resizedImage))
{
using (Image scaleImage = Image.FromStream(imageStream))
{
string outputPath = System.IO.Path.GetDirectoryName(filePath);
outputPath = System.IO.Path.Combine(outputPath, $"{System.IO.Path.GetFileNameWithoutExtension(filePath)}_resized.jpg");
using (FileStream outputFile = System.IO.File.Open(outputPath, FileMode.Create, FileAccess.Write))
{
scaleImage.Save(outputFile, ImageFormat.Jpeg);
}
}
}
}
public static byte[] ScaleImageByPercent(byte[] imageBuffer, int Percent)
{
using (Stream imageStream = new MemoryStream(imageBuffer))
{
using (Image scaleImage = Image.FromStream(imageStream))
{
float scalePercent = ((float)Percent / 100);
int originalWidth = scaleImage.Width;
int originalHeight = scaleImage.Height;
int originalXPoint = 0;
int originalYPoint = 0;
int scaleXPoint = 0;
int scaleYPoint = 0;
int scaleWidth = (int)(originalWidth * scalePercent);
int scaleHeight = (int)(originalHeight * scalePercent);
using (Bitmap scaleBitmapImage = new Bitmap(scaleWidth, scaleHeight, PixelFormat.Format24bppRgb))
{
scaleBitmapImage.SetResolution(scaleImage.HorizontalResolution, scaleImage.VerticalResolution);
Graphics graphicImage = Graphics.FromImage(scaleBitmapImage);
graphicImage.CompositingMode = CompositingMode.SourceCopy;
graphicImage.InterpolationMode = InterpolationMode.NearestNeighbor;
graphicImage.DrawImage(scaleImage,
new Rectangle(scaleXPoint, scaleYPoint, scaleWidth, scaleHeight),
new Rectangle(originalXPoint, originalYPoint, originalWidth, originalHeight),
GraphicsUnit.Pixel);
graphicImage.Dispose();
ImageConverter converter = new ImageConverter();
return (byte[])converter.ConvertTo(scaleBitmapImage, typeof(byte[]));
}
}
}
}
}
}
Here it is the result:
EDIT:
Ok for the webapi interface try doing like this:
HttpResponseMessage result = new HttpResponseMessage(HttpStatusCode.OK);
using (Stream imageStream = new MemoryStream(resizedImage))
{
using (Image scaleImage = Image.FromStream(imageStream))
{
using (MemoryStream ms = new MemoryStream())
{
scaleImage.Save(ms, ImageFormat.Jpeg);
result.Content = new StreamContent(ms);
result.Content.Headers.ContentDisposition = new ContentDispositionHeaderValue("attachment");
result.Content.Headers.ContentType = new MediaTypeHeaderValue("image/jpeg");
}
}
}
return result;

I think that we can reduce size of image by change PixelFormat type.
You can refer to this Reducing Bitmap bit-size in C#

Convert wav streamed over HTTP to mp3, in real-time

Background: I am consuming a service which returns data with a MIME type of audio/wav. I need to provide a playback mechanism for this audio (currently built as an MVC application). As an example, my endpoint looks something like https://audio.fooservice.com/GetAudio?audioId=123
The audio is 8kHz, 1-channel u-law.
Due to varying format support across browsers when using the HTML5 <audio> tag, I am unable to use the original u-law wav because Internet Explorer will not play it.
My proposed solution is to do a real-time conversion from the source format to mp3.
I've cobbled together a partially working solution from various other questions here and in the NAudio forums, but it throws an exception as noted in the comments below:
private void NAudioTest(string url)
{
Stream outStream = new MemoryStream();
var format = WaveFormat.CreateMuLawFormat(8000, 1);
using (Stream ms = new MemoryStream())
{
var request = (HttpWebRequest)WebRequest.Create(url);
request.KeepAlive = false;
request.ProtocolVersion = HttpVersion.Version10;
using (Stream stream = request.GetResponse().GetResponseStream())
{
using (var reader = new RawSourceWaveStream(stream, format))
{
// reader is not seekable; we need to convert to a byte array to seek
var bytes = reader.ToByteArray();
// create a new stream from the byte aray
var seekableStream = new MemoryStream(bytes);
// instantiating a WaveFileReader as follows will throw an exception:
// "System.FormatException: Not a WAVE file - no RIFF header"
using (var waveReader = new WaveFileReader(seekableStream))
{
using (var pcmStream = WaveFormatConversionStream.CreatePcmStream(waveReader))
{
var pcmBytes = pcmStream.ToByteArray();
var mp3 = pcmBytes.ToMp3();
}
}
}
}
}
}
public static class StreamExtensions
{
public static byte[] ToByteArray(this Stream stream)
{
var ms = new MemoryStream();
var buffer = new byte[1024];
int bytes = 0;
while ((bytes = stream.Read(buffer, 0, buffer.Length)) > 0)
ms.Write(buffer, 0, bytes);
return ms.ToArray();
}
}
public static class ByteExtensions
{
public static byte[] ToMp3(this byte[] bytes)
{
using (var outStream = new MemoryStream())
{
using (var ms = new MemoryStream(bytes))
{
using (var reader = new WaveFileReader(ms))
{
using (var writer = new LameMP3FileWriter(outStream, reader.WaveFormat, 64))
{
reader.CopyTo(writer);
return outStream.ToArray();
}
}
}
}
}
}
I've been poking around at this for most of the day and I feel like I'm introducing unnecessary complexity into something that seems like it should be fairly straightforward.
Any help would be much appreciated.
Note: I cannot change the source format and supporting IE is a requirement.
EDIT: I resolved the RIFF exception and am able to produce a stream of the MP3, but it's nothing but white noise. Hopefully I can resolve that as well. My new code is as follows:
[HttpGet]
public ActionResult GetMp3(string url)
{
if (String.IsNullOrWhiteSpace(url))
return null;
var muLawFormat = WaveFormat.CreateMuLawFormat(8000, 1);
var compressedStream = new MemoryStream();
using (var ms = new MemoryStream())
{
var request = (HttpWebRequest)WebRequest.Create(url);
request.KeepAlive = false;
request.ProtocolVersion = HttpVersion.Version10;
using (Stream webStream = request.GetResponse().GetResponseStream())
{
var buffer = new byte[4096];
int read;
while (webStream != null && (read = webStream.Read(buffer, 0, buffer.Length)) > 0)
ms.Write(buffer, 0, read);
}
ms.Position = 0;
using (WaveStream wav = WaveFormatConversionStream.CreatePcmStream(new RawSourceWaveStream(ms, muLawFormat)))
using (var mp3 = new LameMP3FileWriter(compressedStream, new WaveFormat(), LAMEPreset.MEDIUM_FAST))
wav.CopyTo(mp3);
}
compressedStream.Seek(0, 0);
return new FileStreamResult(compressedStream, "audio/mpeg");
}

This works for me (and I needed to do exactly what you wanted to do). Hope this helps someone else as well. I used NAudio with LAME.
You have to make sure that you copy the libmp3lamexx.dll files to your webserver's BIN location or to some folder in the %PATH% variable, else it won't work.
string sq = /* URL of WAV file (http://foo.com/blah.wav) */
Response.ContentType = "audio/mpeg";
using (WebClient wc = new WebClient())
{
if (!sq.ToLower().EndsWith(".wav"))
{
byte[] rawFile = wc.DownloadData(sq.Trim());
Response.OutputStream.Write(rawFile, 0, rawFile.Length);
}
else
{
using (var wavReader = new WaveFileReader(new MemoryStream(wc.DownloadData(sq.Trim()))))
{
try
{
using (var wavWriter = new LameMP3FileWriter(Response.OutputStream, wavReader.WaveFormat, LAMEPreset.ABR_128))
{
wavReader.CopyTo(wavWriter);
}
}
catch (ArgumentException)
{
var newFormat = new WaveFormat(wavReader.WaveFormat.SampleRate, 16, 2);
using (var pcmStream = new WaveFormatConversionStream(newFormat, wavReader))
{
using (var wavWriter = new LameMP3FileWriter(Response.OutputStream, pcmStream.WaveFormat, LAMEPreset.ABR_128))
{
pcmStream.CopyTo(wavWriter);
}
}
}
}
}
Response.Flush();
Response.End();
}

Compression/Decompression string with C#

I am newbie in .net. I am doing compression and decompression string in C#. There is a XML and I am converting in string and after that I am doing compression and decompression.There is no compilation error in my code except when I decompression my code and return my string, its returning only half of the XML.
Below is my code, please correct me where I am wrong.
Code:
class Program
{
public static string Zip(string value)
{
//Transform string into byte[]
byte[] byteArray = new byte[value.Length];
int indexBA = 0;
foreach (char item in value.ToCharArray())
{
byteArray[indexBA++] = (byte)item;
}
//Prepare for compress
System.IO.MemoryStream ms = new System.IO.MemoryStream();
System.IO.Compression.GZipStream sw = new System.IO.Compression.GZipStream(ms, System.IO.Compression.CompressionMode.Compress);
//Compress
sw.Write(byteArray, 0, byteArray.Length);
//Close, DO NOT FLUSH cause bytes will go missing...
sw.Close();
//Transform byte[] zip data to string
byteArray = ms.ToArray();
System.Text.StringBuilder sB = new System.Text.StringBuilder(byteArray.Length);
foreach (byte item in byteArray)
{
sB.Append((char)item);
}
ms.Close();
sw.Dispose();
ms.Dispose();
return sB.ToString();
}
public static string UnZip(string value)
{
//Transform string into byte[]
byte[] byteArray = new byte[value.Length];
int indexBA = 0;
foreach (char item in value.ToCharArray())
{
byteArray[indexBA++] = (byte)item;
}
//Prepare for decompress
System.IO.MemoryStream ms = new System.IO.MemoryStream(byteArray);
System.IO.Compression.GZipStream sr = new System.IO.Compression.GZipStream(ms,
System.IO.Compression.CompressionMode.Decompress);
//Reset variable to collect uncompressed result
byteArray = new byte[byteArray.Length];
//Decompress
int rByte = sr.Read(byteArray, 0, byteArray.Length);
//Transform byte[] unzip data to string
System.Text.StringBuilder sB = new System.Text.StringBuilder(rByte);
//Read the number of bytes GZipStream red and do not a for each bytes in
//resultByteArray;
for (int i = 0; i < rByte; i++)
{
sB.Append((char)byteArray[i]);
}
sr.Close();
ms.Close();
sr.Dispose();
ms.Dispose();
return sB.ToString();
}
static void Main(string[] args)
{
XDocument doc = XDocument.Load(#"D:\RSP.xml");
string val = doc.ToString(SaveOptions.DisableFormatting);
val = Zip(val);
val = UnZip(val);
}
}
My XML size is 63KB.

The code to compress/decompress a string
public static void CopyTo(Stream src, Stream dest) {
byte[] bytes = new byte[4096];
int cnt;
while ((cnt = src.Read(bytes, 0, bytes.Length)) != 0) {
dest.Write(bytes, 0, cnt);
}
}
public static byte[] Zip(string str) {
var bytes = Encoding.UTF8.GetBytes(str);
using (var msi = new MemoryStream(bytes))
using (var mso = new MemoryStream()) {
using (var gs = new GZipStream(mso, CompressionMode.Compress)) {
//msi.CopyTo(gs);
CopyTo(msi, gs);
}
return mso.ToArray();
}
}
public static string Unzip(byte[] bytes) {
using (var msi = new MemoryStream(bytes))
using (var mso = new MemoryStream()) {
using (var gs = new GZipStream(msi, CompressionMode.Decompress)) {
//gs.CopyTo(mso);
CopyTo(gs, mso);
}
return Encoding.UTF8.GetString(mso.ToArray());
}
}
static void Main(string[] args) {
byte[] r1 = Zip("StringStringStringStringStringStringStringStringStringStringStringStringStringString");
string r2 = Unzip(r1);
}
Remember that Zip returns a byte[], while Unzip returns a string. If you want a string from Zip you can Base64 encode it (for example by using Convert.ToBase64String(r1)) (the result of Zip is VERY binary! It isn't something you can print to the screen or write directly in an XML)
The version suggested is for .NET 2.0, for .NET 4.0 use the MemoryStream.CopyTo.
IMPORTANT: The compressed contents cannot be written to the output stream until the GZipStream knows that it has all of the input (i.e., to effectively compress it needs all of the data). You need to make sure that you Dispose() of the GZipStream before inspecting the output stream (e.g., mso.ToArray()). This is done with the using() { } block above. Note that the GZipStream is the innermost block and the contents are accessed outside of it. The same goes for decompressing: Dispose() of the GZipStream before attempting to access the data.

according to
this snippet
i use this code and it's working fine:
using System;
using System.IO;
using System.IO.Compression;
using System.Text;
namespace CompressString
{
internal static class StringCompressor
{
/// <summary>
/// Compresses the string.
/// </summary>
/// <param name="text">The text.</param>
/// <returns></returns>
public static string CompressString(string text)
{
byte[] buffer = Encoding.UTF8.GetBytes(text);
var memoryStream = new MemoryStream();
using (var gZipStream = new GZipStream(memoryStream, CompressionMode.Compress, true))
{
gZipStream.Write(buffer, 0, buffer.Length);
}
memoryStream.Position = 0;
var compressedData = new byte[memoryStream.Length];
memoryStream.Read(compressedData, 0, compressedData.Length);
var gZipBuffer = new byte[compressedData.Length + 4];
Buffer.BlockCopy(compressedData, 0, gZipBuffer, 4, compressedData.Length);
Buffer.BlockCopy(BitConverter.GetBytes(buffer.Length), 0, gZipBuffer, 0, 4);
return Convert.ToBase64String(gZipBuffer);
}
/// <summary>
/// Decompresses the string.
/// </summary>
/// <param name="compressedText">The compressed text.</param>
/// <returns></returns>
public static string DecompressString(string compressedText)
{
byte[] gZipBuffer = Convert.FromBase64String(compressedText);
using (var memoryStream = new MemoryStream())
{
int dataLength = BitConverter.ToInt32(gZipBuffer, 0);
memoryStream.Write(gZipBuffer, 4, gZipBuffer.Length - 4);
var buffer = new byte[dataLength];
memoryStream.Position = 0;
using (var gZipStream = new GZipStream(memoryStream, CompressionMode.Decompress))
{
gZipStream.Read(buffer, 0, buffer.Length);
}
return Encoding.UTF8.GetString(buffer);
}
}
}
}

With the advent of .NET 4.0 (and higher) with the Stream.CopyTo() methods, I thought I would post an updated approach.
I also think the below version is useful as a clear example of a self-contained class for compressing regular strings to Base64 encoded strings, and vice versa:
public static class StringCompression
{
/// <summary>
/// Compresses a string and returns a deflate compressed, Base64 encoded string.
/// </summary>
/// <param name="uncompressedString">String to compress</param>
public static string Compress(string uncompressedString)
{
byte[] compressedBytes;
using (var uncompressedStream = new MemoryStream(Encoding.UTF8.GetBytes(uncompressedString)))
{
using (var compressedStream = new MemoryStream())
{
// setting the leaveOpen parameter to true to ensure that compressedStream will not be closed when compressorStream is disposed
// this allows compressorStream to close and flush its buffers to compressedStream and guarantees that compressedStream.ToArray() can be called afterward
// although MSDN documentation states that ToArray() can be called on a closed MemoryStream, I don't want to rely on that very odd behavior should it ever change
using (var compressorStream = new DeflateStream(compressedStream, CompressionLevel.Fastest, true))
{
uncompressedStream.CopyTo(compressorStream);
}
// call compressedStream.ToArray() after the enclosing DeflateStream has closed and flushed its buffer to compressedStream
compressedBytes = compressedStream.ToArray();
}
}
return Convert.ToBase64String(compressedBytes);
}
/// <summary>
/// Decompresses a deflate compressed, Base64 encoded string and returns an uncompressed string.
/// </summary>
/// <param name="compressedString">String to decompress.</param>
public static string Decompress(string compressedString)
{
byte[] decompressedBytes;
var compressedStream = new MemoryStream(Convert.FromBase64String(compressedString));
using (var decompressorStream = new DeflateStream(compressedStream, CompressionMode.Decompress))
{
using (var decompressedStream = new MemoryStream())
{
decompressorStream.CopyTo(decompressedStream);
decompressedBytes = decompressedStream.ToArray();
}
}
return Encoding.UTF8.GetString(decompressedBytes);
}
}
Here’s another approach using the extension methods technique to extend the String class to add string compression and decompression. You can drop the class below into an existing project and then use thusly:
var uncompressedString = "Hello World!";
var compressedString = uncompressedString.Compress();
and
var decompressedString = compressedString.Decompress();
To wit:
public static class Extensions
{
/// <summary>
/// Compresses a string and returns a deflate compressed, Base64 encoded string.
/// </summary>
/// <param name="uncompressedString">String to compress</param>
public static string Compress(this string uncompressedString)
{
byte[] compressedBytes;
using (var uncompressedStream = new MemoryStream(Encoding.UTF8.GetBytes(uncompressedString)))
{
using (var compressedStream = new MemoryStream())
{
// setting the leaveOpen parameter to true to ensure that compressedStream will not be closed when compressorStream is disposed
// this allows compressorStream to close and flush its buffers to compressedStream and guarantees that compressedStream.ToArray() can be called afterward
// although MSDN documentation states that ToArray() can be called on a closed MemoryStream, I don't want to rely on that very odd behavior should it ever change
using (var compressorStream = new DeflateStream(compressedStream, CompressionLevel.Fastest, true))
{
uncompressedStream.CopyTo(compressorStream);
}
// call compressedStream.ToArray() after the enclosing DeflateStream has closed and flushed its buffer to compressedStream
compressedBytes = compressedStream.ToArray();
}
}
return Convert.ToBase64String(compressedBytes);
}
/// <summary>
/// Decompresses a deflate compressed, Base64 encoded string and returns an uncompressed string.
/// </summary>
/// <param name="compressedString">String to decompress.</param>
public static string Decompress(this string compressedString)
{
byte[] decompressedBytes;
var compressedStream = new MemoryStream(Convert.FromBase64String(compressedString));
using (var decompressorStream = new DeflateStream(compressedStream, CompressionMode.Decompress))
{
using (var decompressedStream = new MemoryStream())
{
decompressorStream.CopyTo(decompressedStream);
decompressedBytes = decompressedStream.ToArray();
}
}
return Encoding.UTF8.GetString(decompressedBytes);
}
}

I like #fubo's answer the best but I think this is much more elegant.
This method is more compatible because it doesn't manually store the length up front.
Also I've exposed extensions to support compression for string to string, byte[] to byte[], and Stream to Stream.
public static class ZipExtensions
{
public static string CompressToBase64(this string data)
{
return Convert.ToBase64String(Encoding.UTF8.GetBytes(data).Compress());
}
public static string DecompressFromBase64(this string data)
{
return Encoding.UTF8.GetString(Convert.FromBase64String(data).Decompress());
}
public static byte[] Compress(this byte[] data)
{
using (var sourceStream = new MemoryStream(data))
using (var destinationStream = new MemoryStream())
{
sourceStream.CompressTo(destinationStream);
return destinationStream.ToArray();
}
}
public static byte[] Decompress(this byte[] data)
{
using (var sourceStream = new MemoryStream(data))
using (var destinationStream = new MemoryStream())
{
sourceStream.DecompressTo(destinationStream);
return destinationStream.ToArray();
}
}
public static void CompressTo(this Stream stream, Stream outputStream)
{
using (var gZipStream = new GZipStream(outputStream, CompressionMode.Compress))
{
stream.CopyTo(gZipStream);
gZipStream.Flush();
}
}
public static void DecompressTo(this Stream stream, Stream outputStream)
{
using (var gZipStream = new GZipStream(stream, CompressionMode.Decompress))
{
gZipStream.CopyTo(outputStream);
}
}
}

This is an updated version for .NET 4.5 and newer using async/await and IEnumerables:
public static class CompressionExtensions
{
public static async Task<IEnumerable<byte>> Zip(this object obj)
{
byte[] bytes = obj.Serialize();
using (MemoryStream msi = new MemoryStream(bytes))
using (MemoryStream mso = new MemoryStream())
{
using (var gs = new GZipStream(mso, CompressionMode.Compress))
await msi.CopyToAsync(gs);
return mso.ToArray().AsEnumerable();
}
}
public static async Task<object> Unzip(this byte[] bytes)
{
using (MemoryStream msi = new MemoryStream(bytes))
using (MemoryStream mso = new MemoryStream())
{
using (var gs = new GZipStream(msi, CompressionMode.Decompress))
{
// Sync example:
//gs.CopyTo(mso);
// Async way (take care of using async keyword on the method definition)
await gs.CopyToAsync(mso);
}
return mso.ToArray().Deserialize();
}
}
}
public static class SerializerExtensions
{
public static byte[] Serialize<T>(this T objectToWrite)
{
using (MemoryStream stream = new MemoryStream())
{
BinaryFormatter binaryFormatter = new BinaryFormatter();
binaryFormatter.Serialize(stream, objectToWrite);
return stream.GetBuffer();
}
}
public static async Task<T> _Deserialize<T>(this byte[] arr)
{
using (MemoryStream stream = new MemoryStream())
{
BinaryFormatter binaryFormatter = new BinaryFormatter();
await stream.WriteAsync(arr, 0, arr.Length);
stream.Position = 0;
return (T)binaryFormatter.Deserialize(stream);
}
}
public static async Task<object> Deserialize(this byte[] arr)
{
object obj = await arr._Deserialize<object>();
return obj;
}
}
With this you can serialize everything BinaryFormatter supports, instead only of strings.
Edit:
In case, you need take care of Encoding, you could just use Convert.ToBase64String(byte[])...
Take a look at this answer if you need an example!

For those who still getting The magic number in GZip header is not correct. Make sure you are passing in a GZip stream. ERROR
and if your string was zipped using php you'll need to do something like:
public static string decodeDecompress(string originalReceivedSrc) {
byte[] bytes = Convert.FromBase64String(originalReceivedSrc);
using (var mem = new MemoryStream()) {
//the trick is here
mem.Write(new byte[] { 0x1f, 0x8b, 0x08, 0x00, 0x00, 0x00, 0x00, 0x00 }, 0, 8);
mem.Write(bytes, 0, bytes.Length);
mem.Position = 0;
using (var gzip = new GZipStream(mem, CompressionMode.Decompress))
using (var reader = new StreamReader(gzip)) {
return reader.ReadToEnd();
}
}
}

We can reduce code complexity by using StreamReader and StreamWriter rather than manually converting strings to byte arrays. Three streams is all you need:
public static byte[] Zip(string uncompressed)
{
byte[] ret;
using (var outputMemory = new MemoryStream())
{
using (var gz = new GZipStream(outputMemory, CompressionLevel.Optimal))
{
using (var sw = new StreamWriter(gz, Encoding.UTF8))
{
sw.Write(uncompressed);
}
}
ret = outputMemory.ToArray();
}
return ret;
}
public static string Unzip(byte[] compressed)
{
string ret = null;
using (var inputMemory = new MemoryStream(compressed))
{
using (var gz = new GZipStream(inputMemory, CompressionMode.Decompress))
{
using (var sr = new StreamReader(gz, Encoding.UTF8))
{
ret = sr.ReadToEnd();
}
}
}
return ret;
}

For .net6 cross platform Compression/Decompression string with C# using SharpZipLib library. Test for ubuntu(18.0.x) and windows.
#region helper
private byte[] Zip(string text)
{
if (text == null)
return null;
byte[] ret;
using (var outputMemory = new MemoryStream())
{
using (var gz = new GZipStream(outputMemory, CompressionLevel.Optimal))
{
using (var sw = new StreamWriter(gz, Encoding.UTF8))
{
sw.Write(text);
}
}
ret = outputMemory.ToArray();
}
return ret;
}
private string Unzip(byte[] bytes)
{
string ret = null;
using (var inputMemory = new MemoryStream(bytes))
{
using (var gz = new GZipStream(inputMemory, CompressionMode.Decompress))
{
using (var sr = new StreamReader(gz, Encoding.UTF8))
{
ret = sr.ReadToEnd();
}
}
}
return ret;
}
#endregion