Can anyone please tell me how an image(.jpg,.gif,.bmp) is converted into a byte array ?
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Where do you have your image? In a file or in an Image object or some Stream?Albin Sunnanbo– Albin Sunnanbo2011-02-19 13:13:27 +00:00Commented Feb 19, 2011 at 13:13
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image is uploaded into a picturebox using an OpenFileDialogRiya– Riya2011-02-19 13:14:46 +00:00Commented Feb 19, 2011 at 13:14
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Why do you need your image as a byte array? For storage? or are you trying to manipulate the image?yhw42– yhw422011-02-19 13:43:12 +00:00Commented Feb 19, 2011 at 13:43
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6 Answers
The easiest way to convert an image to bytes is to use the ImageConverter class under the System.Drawing namespace
public static byte[] ImageToByte(Image img)
{
ImageConverter converter = new ImageConverter();
return (byte[])converter.ConvertTo(img, typeof(byte[]));
}
Comments
I've assumed what you want is the pixel values. Assuming bitmap is a System.Windows.Media.Imaging.BitmapSource:
int stride = bitmap.PixelWidth * ((bitmap.Format.BitsPerPixel + 7) / 8);
byte[] bmpPixels = new byte[bitmap.PixelHeight * stride];
bitmap.CopyPixels(bmpPixels, stride, 0);
Note that the 'stride' is the number of bytes required for each row of pixel ddata. Some more explanation available here.
7 Comments
Cocowalla
Why the downvote? Surely the question can be interpreted as 'I want the image pixel values as a byte array' or 'I want the image file as a byte array'?
MusiGenesis
Your answer didn't originally have the third line, and your first line threw me until I had some coffee. Edit it and I'll undo my down-vote.
Cocowalla
Fair point, thanks for explaining :) I've added a brief note on what the stride is.
MusiGenesis
Actually, are you sure your stride calculation is right? The stride needs to be 32-bit aligned, but I think your code just makes it 8-bit aligned.
Cocowalla
It was quite a while ago I wrote the code, and I remember spending quite some time on figuring it out. I definately works :) Some more here stackoverflow.com/questions/2185944/… and here stackoverflow.com/questions/1983781/…. My head hurts :)
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If your image is already in the form of a System.Drawing.Image, then you can do something like this:
public byte[] convertImageToByteArray(System.Drawing.Image image)
{
using (MemoryStream ms = new MemoryStream())
{
image.Save(ms, System.Drawing.Imaging.ImageFormat.Gif);
// or whatever output format you like
return ms.ToArray();
}
}
You would use this function with the image in your picture box control like this:
byte[] imageBytes = convertImageToByteArray(pictureBox1.Image);
1 Comment
MusiGenesis
@riya7887: please use my edited version above, since it disposes the stream properly.
to get the bytes from any file try:
byte[] bytes = File.ReadAllBytes(pathToFile);
Comments
Based off of MusiGenesis; helped me a lot but I had many image types. This will save any image type that it can read.
System.Drawing.Imaging.ImageFormat ImageFormat = imageToConvert.RawFormat;
byte[] Ret;
try
{
using (MemoryStream ms = new MemoryStream())
{
imageToConvert.Save(ms, ImageFormat);
Ret = ms.ToArray();
}
}
catch (Exception) { throw; }
return Ret;
Comments
You can use File.ReadAllBytes method to get bytes
If you are using FileUpload class then you can use FileBytes Property to get the Bytes as Byte Array.
