Using C#, I'm trying to load a JPEG file from disk and convert it to a byte array. So far, I have this code:
static void Main(string[] args)
{
System.Windows.Media.Imaging.BitmapFrame bitmapFrame;
using (var fs = new System.IO.FileStream(#"C:\Lenna.jpg", FileMode.Open))
{
bitmapFrame = BitmapFrame.Create(fs);
}
System.Windows.Media.Imaging.BitmapEncoder encoder =
new System.Windows.Media.Imaging.JpegBitmapEncoder();
encoder.Frames.Add(bitmapFrame);
byte[] myBytes;
using (var memoryStream = new System.IO.MemoryStream())
{
encoder.Save(memoryStream); // Line ARGH
// mission accomplished if myBytes is populated
myBytes = memoryStream.ToArray();
}
}
However, executing line ARGH gives me the message:
COMException was unhandled. The handle is invalid. (Exception from
HRESULT: 0x80070006 (E_HANDLE))
I don't think there is anything special about the file Lenna.jpg - I downloaded it from http://computervision.wikia.com/wiki/File:Lenna.jpg. Can you tell what is wrong with the above code?
Check the examples from this article: http://www.codeproject.com/KB/recipes/ImageConverter.aspx
Also it's better to use classes from System.Drawing
Image img = Image.FromFile(#"C:\Lenna.jpg");
byte[] arr;
using (MemoryStream ms = new MemoryStream())
{
img.Save(ms, System.Drawing.Imaging.ImageFormat.Jpeg);
arr = ms.ToArray();
}
Other suggestion:
byte[] image = System.IO.File.ReadAllBytes ( Server.MapPath ( "noimage.png" ) );
Should be working not only with images.
public byte[] imageToByteArray(System.Drawing.Image imageIn)
{
MemoryStream ms = new MemoryStream();
imageIn.Save(ms,System.Drawing.Imaging.ImageFormat.Gif);
return ms.ToArray();
}
The reason this error happens is because the BitmapFrame.Create() method you are using defaults to an OnDemand load. The BitmapFrame doesn't try to read the stream it's associated with until the call to encoder.Save, by which point the stream is already disposed.
You could either wrap the entire function in the using {} block, or use an alternative BitmapFrame.Create(), such as:
BitmapFrame.Create(fs, BitmapCreateOptions.None, BitmapCacheOption.OnLoad);
Related
I am trying to compress image(usually around 5-30) quality / size with Magick.NET library, and I cant really understand how can I use ImageOptimizer class and call LosslessCompress() method using stream.
Do I need to use FileStream or MemoryStream?
Do I need to save / create a temp file on server for each image and then proceed with the compression flow? (Performance?)
Anything else?
Simple Code example:
private byte[] ConvertImageToByteArray(IFormFile image)
{
byte[] result = null;
// filestream
using (var fileStream = image.OpenReadStream())
// memory stream
using (var memoryStream = new MemoryStream())
{
var before = fileStream.Length;
ImageOptimizer optimizer = new ImageOptimizer();
optimizer.LosslessCompress(fileStream); // what & how can I pass here stream?
var after = fileStream.Length;
// convert to byte[]
fileStream.CopyTo(memoryStream);
result = memoryStream.ToArray();
}
return result;
}
You cannot use the fileStream because the stream needs to be both readable and writable. If you first copy the data to a memorystream you can then compresses the image in that stream. Your code should be changed to this:
private byte[] ConvertImageToByteArray(IFormFile image)
{
byte[] result = null;
// filestream
using (var fileStream = image.OpenReadStream())
// memory stream
using (var memoryStream = new MemoryStream())
{
fileStream.CopyTo(memoryStream);
memoryStream.Position = 0; // The position needs to be reset.
var before = memoryStream.Length;
ImageOptimizer optimizer = new ImageOptimizer();
optimizer.LosslessCompress(memoryStream);
var after = memoryStream.Length;
// convert to byte[]
result = memoryStream.ToArray();
}
return result;
}
I have the following code to convert image to base64:
private void btnSave_Click(object sender, RoutedEventArgs e)
{
StreamResourceInfo sri = null;
Uri uri = new Uri("Checked.png", UriKind.Relative);
sri = Application.GetResourceStream(uri);
BitmapImage bitmap = new BitmapImage();
bitmap.SetSource(sri.Stream);
WriteableBitmap wb = new WriteableBitmap(bitmap);
MemoryStream ms = new MemoryStream();
wb.SaveJpeg(ms, bitmap.PixelWidth, bitmap.PixelHeight, 0, 100);
byte[] imageBytes = ms.ToArray();
base64 = System.Convert.ToBase64String(imageBytes);
}
And the following code to get Bitmap image form base 64:
public static BitmapImage base64image(string base64string)
{
byte[] fileBytes = Convert.FromBase64String(base64string);
using (MemoryStream ms = new MemoryStream(fileBytes, 0, fileBytes.Length))
{
ms.Write(fileBytes, 0, fileBytes.Length);
BitmapImage bitmapImage = new BitmapImage();
bitmapImage.SetSource(ms);
return bitmapImage;
}
}
So when i convert and deconvert it is blank.
I know that deconverter works, because, when i give him exact string:
string base64="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";
Which is my Checked.png converted in online converter. It decompreses perfectly.
And this is my base64, which i get by converting:
"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"
My problem is that string which i get as base64 from my code - is incorrect *What i did wrong?*
What about trying:
public static BitmapImage base64image(string base64string)
{
byte[] fileBytes = Convert.FromBase64String(base64string);
using (MemoryStream ms = new MemoryStream(fileBytes))
{
Image streamImage = Image.FromStream(ms);
context.Response.ContentType = "image/jpeg";
streamImage.Save(context.Response.OutputStream, ImageFormat.Jpeg);
return streamImage;
}
}
I agree with Alexei that your code for reading the image in does look a little strange. I've recently written some code for a similar task that I was doing which might point you in the right direction:
string fileContent = null;
/* Check the file actually has some content to display to the user */
if (uploadFile != null && uploadFile.ContentLength > 0)
{
byte[] fileBytes = new byte[uploadFile.ContentLength];
int byteCount = uploadFile.InputStream.Read(fileBytes, 0, (int)uploadFile.ContentLength);
if (byteCount > 0)
{
fileContent = CreateBase64Image(fileBytes);
}
}
private string CreateBase64Image(byte[] fileBytes)
{
Image streamImage;
/* Ensure we've streamed the document out correctly before we commit to the conversion */
using (MemoryStream ms = new MemoryStream(fileBytes))
{
/* Create a new image, saved as a scaled version of the original */
streamImage = ScaleImage(Image.FromStream(ms));
}
using (MemoryStream ms = new MemoryStream())
{
/* Convert this image back to a base64 string */
streamImage.Save(ms, System.Drawing.Imaging.ImageFormat.Png);
return Convert.ToBase64String(ms.ToArray());
}
}
not an answer: more of a long comment ... OP states that decoding code works perfectly fine, also it looks suspicios. Also code assumed to be verified to work on PNG images, but saving code explicitly produces valid JPG with SaveJpeg call...
Your code that creates stream for reading looks strange - you create stream over existing byte array, than write the same bytes into that stream, and that pass that stream without seeking back to 0 to some method.
Potential fix (assuming BitampImage can accept JPG stream):
don't call Write at all as stream already have the bytes you want
set ms.Position = 0 after writing to the stream.
Note: I'm not sure if it is OK to dispose stream that is a source for BitmapImage, you may need to remove using too.
I'm about to lose my freaking mind. I've been trying to get GzipStream to compress a string for the past hour, but for whatever reason, it refuses to write the entire byte array to the memory stream. At first I thought it had something to do with the using statements, but even after removing them it didn't seem to make a difference.
Initial config:
var str = "Here is a relatively simple string to compress";
byte[] compressedBytes;
string returnedData;
var bytes = Encoding.UTF8.GetBytes(str);
Works correctly (writes 64 length byte array):
using (var msi = new MemoryStream(bytes))
using (var mso = new MemoryStream()) {
using (var gs = new GZipStream(mso, CompressionMode.Compress)) {
msi.CopyTo(gs);
}
compressedBytes = mso.ToArray();
}
Fails (writes 10 length byte array):
using(var mso = new MemoryStream())
using(var msi = new MemoryStream(bytes))
using(var zip = new GZipStream(mso, CompressionMode.Compress))
{
msi.CopyTo(zip);
compressedBytes = mso.ToArray();
}
Also fails (writes 10 length byte array):
var mso = new MemoryStream();
var msi = new MemoryStream(bytes);
var zip = new GZipStream(mso, CompressionMode.Compress);
msi.CopyTo(zip);
compressedBytes = mso.ToArray();
Can somebody explain why the first one works but in the other two I'm getting these incomplete arrays? Is something getting disposed out from under me? For that matter, is there a way for me to avoid using two memorystreams?
Thanks,
Zoombini
System.IO.Compression.GZipStream has to be closed (disposed) before you can use the underlying stream, because
It works block oriented
It has to write the footer, including the checksum (see the file format description on Wikipedia)
You're trying to get the the compressed data before GZipStream is closed. This doesn't return the full data, as you've seen. The reason the first one works is because you're calling compressedBytes = mso.ToArray(); after GZipStream has been disposed. So, untested but in theory, you should be able to modify your second code slightly like this to get it to work.
using(var mso = new MemoryStream())
{
using(var msi = new MemoryStream(bytes))
using(var zip = new GZipStream(mso, CompressionMode.Compress))
{
msi.CopyTo(zip);
}
compressedBytes = mso.ToArray();
}
As others have said, you need to close the GZipStream before you can get the full data. A using statement will cause the Dispose method to be called on the stream at the end of the block, which will close the stream if it is not already closed. All of your examples above will work as expected if you place zip.Close(); after msi.CopyTo(zip);.
You can eliminate one of the MemoryStreams if you write it this way:
using (MemoryStream mso = new MemoryStream())
{
using (GZipStream zip = new GZipStream(mso, CompressionMode.Compress))
{
zip.Write(bytes, 0, bytes.Length);
}
compressedBytes = mso.ToArray();
}
I have a BitmapImage that I'm using in a WPF application, I later want to save it to a database as a byte array (I guess it's the best way), how can I perform this conversion?
Or, alternatively, is there a better way to save a BitmapImage (or any of its base classes, BitmapSource or ImageSource) to a data repository?
To convert to a byte[] you can use a MemoryStream:
byte[] data;
JpegBitmapEncoder encoder = new JpegBitmapEncoder();
encoder.Frames.Add(BitmapFrame.Create(bitmapImage));
using(MemoryStream ms = new MemoryStream())
{
encoder.Save(ms);
data = ms.ToArray();
}
Instead of the JpegBitmapEncoder you can use whatever BitmapEncoder you like as casperOne said.
If you are using MS SQL you could also use a image-Column as MS SQL supports that datatype, but you still would need to convert the BitmapImage somehow.
You will have to use an instance of a class that derives from BitmapEncoder (such as BmpBitmapEncoder) and call the Save method to save the BitmapSource to a Stream.
You would choose the specific encoder depending on the format you want to save the image in.
write it to a MemoryStream, then you can access the bytes from there.
something kinda like this:
public Byte[] ImageToByte(BitmapImage imageSource)
{
Stream stream = imageSource.StreamSource;
Byte[] buffer = null;
if (stream != null && stream.Length > 0)
{
using (BinaryReader br = new BinaryReader(stream))
{
buffer = br.ReadBytes((Int32)stream.Length);
}
}
return buffer;
}
You can give a formate of bitmap:
Image bmp = new Bitmap(Screen.PrimaryScreen.Bounds.Width, Screen.PrimaryScreen.Bounds.Height);
Graphics.FromImage(bmp).CopyFromScreen(new Point(0, 0), new Point(0, 0), Screen.PrimaryScreen.Bounds.Size);
MemoryStream m = new MemoryStream();
bmp.Save(m, System.Drawing.Imaging.ImageFormat.Png);
byte[] imageBytes = m.ToArray();
string base64String = Convert.ToBase64String(imageBytes);
Just use a MemoryStream.
byte[] data = null;
using(MemoryStream ms = new MemoryStream())
{
bitmapImage.Save(ms);
data = ms.ToArray();
}
How does one convert between System.Drawing.Icon type and byte[]? I'm looking for something simple that can (hopefully) work in .NET2.
You go via a MemoryStream, basically:
public static byte[] IconToBytes(Icon icon)
{
using (MemoryStream ms = new MemoryStream())
{
icon.Save(ms);
return ms.ToArray();
}
}
public static Icon BytesToIcon(byte[] bytes)
{
using (MemoryStream ms = new MemoryStream(bytes))
{
return new Icon(ms);
}
}
(Historical note: I wasn't sure whether or not it was safe to dispose of the stream passed to the constructor. It isn't safe to do so for Bitmap, for example... that holds on to the stream and may read from it later. Apparently it's okay for Icon though. I wish MSDN made this clearer...)
See:
http://social.msdn.microsoft.com/Forums/en-US/csharpgeneral/thread/1551fd3b-02b6-4479-852a-dfea4b610c35
Ex (there are multiple ways)
private byte[] GetBytes( Icon icon )
{
MemoryStream ms = new MemoryStream();
icon.Save( ms );
return ms.ToArray();
}
And:
Bitmap bmpIcon = icon.ToBitmap();
using (System.IO.MemoryStream ms = new System.IO.MemoryStream())
{
bmpIcon.Save(ms, System.Drawing.Imaging.ImageFormat.Bmp);
return ms.ToArray();
}
... And back again
public static Icon IconFromBytes(byte[] bytes) {
using(var ms = new MemoryStream(bytes)) {
return new Icon(ms);
}
}
The Icon class reads from the stream as soon as it's constructed. No harm in closing MS.