将 Image 转换为 Byte 数组的最快方法

我正在制作远程桌面共享应用程序，其中我捕获了桌面的图像，压缩它，并发送到接收器。为了压缩图像，我需要把它转换成一个字节[]。

目前我使用的是:

public byte[] imageToByteArray(System.Drawing.Image imageIn)
{
MemoryStream ms = new MemoryStream();
imageIn.Save(ms,System.Drawing.Imaging.ImageFormat.Gif);
return  ms.ToArray();
}


public Image byteArrayToImage(byte[] byteArrayIn)
{
MemoryStream ms = new MemoryStream(byteArrayIn);
Image returnImage = Image.FromStream(ms);
return returnImage;
}

但是我不喜欢它，因为我必须将它保存在 ImageFormat 中，这可能会消耗资源(Slow Down)并产生不同的压缩结果。复制和记忆，但我无法理解他们。

那么有没有其他的方法来实现这个目标呢？

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最佳答案

So is there any other method to achieve this goal?

No. In order to convert an image to a byte array you have to specify an image format - just as you have to specify an encoding when you convert text to a byte array.

If you're worried about compression artefacts, pick a lossless format. If you're worried about CPU resources, pick a format which doesn't bother compressing - just raw ARGB pixels, for example. But of course that will lead to a larger byte array.

Note that if you pick a format which does include compression, there's no point in then compressing the byte array afterwards - it's almost certain to have no beneficial effect.

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I'm not sure if you're going to get any huge gains for reasons Jon Skeet pointed out. However, you could try and benchmark the TypeConvert.ConvertTo method and see how it compares to using your current method.

ImageConverter converter = new ImageConverter();
byte[] imgArray = (byte[])converter.ConvertTo(imageIn, typeof(byte[]));
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public static byte[] ReadImageFile(string imageLocation)
{
byte[] imageData = null;
FileInfo fileInfo = new FileInfo(imageLocation);
long imageFileLength = fileInfo.Length;
FileStream fs = new FileStream(imageLocation, FileMode.Open, FileAccess.Read);
BinaryReader br = new BinaryReader(fs);
imageData = br.ReadBytes((int)imageFileLength);
return imageData;
}
小开

There is a RawFormat property of Image parameter which returns the file format of the image. You might try the following:

// extension method
public static byte[] imageToByteArray(this System.Drawing.Image image)
{
using(var ms = new MemoryStream())
{
image.Save(ms, image.RawFormat);
return ms.ToArray();
}
}
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The fastest way i could find out is this :

var myArray = (byte[]) new ImageConverter().ConvertTo(InputImg, typeof(byte[]));

Hope to be useful

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public static class HelperExtensions
{
//Convert Image to byte[] array:
public static byte[] ToByteArray(this Image imageIn)
{
var ms = new MemoryStream();
imageIn.Save(ms, System.Drawing.Imaging.ImageFormat.Png);
return ms.ToArray();
}


//Convert byte[] array to Image:
public static Image ToImage(this byte[] byteArrayIn)
{
var ms = new MemoryStream(byteArrayIn);
var returnImage = Image.FromStream(ms);
return returnImage;
}
}
小开

Try following Code:

public Byte[] ConvertPictureToByte(System.Drawing.Image PictureFile)
{
using (var MemStrm = new MemoryStream())
{
PictureFile.Save(MemStrm,PictureFile.RawFormat);
return  MemStrm.ToArray();
}
}

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