I have a dynamically created Image control that is populated via a OpenFileDialog like:
OpenFileDialog dialog = new OpenFileDialog();
if (dialog.ShowDialog() == true)
{
using (FileStream stream = dialog.File.OpenRead())
{
BitmapImage bmp = new BitmapImage();
bmp.SetSource(stream);
myImage.Source = bmp;
}
}
I want to send the image back to the server in a separate function call, as string via a web service.
How do I get a memory stream / base64 string from myImage.Source
Here's an alternative which should work (without BmpBitmapEncoder). It's uses the FileStream stream to create the byte array that is then converted to a Base64 string. This assumes you want to do this within the scope of the current code.
Byte[] bytes = new Byte[stream.Length];
stream.Read(bytes, 0, bytes.Length);
return Convert.ToBase64String(bytes);
Make sure you have http://imagetools.codeplex.com/
Then you can do this:
ImageSource myStartImage;
var image = ((WriteableBitmap) myStartImage).ToImage();
var encoder = new PngEncoder( false );
MemoryStream stream = new MemoryStream();
encoder.Encode( image, stream );
var myStartImageByteStream = stream.GetBuffer();
Then for Base64:
string encodedData = Convert.ToBase64String(myStartImageByteStream);
Related
The DiffuseMap property of a PhongMaterial accepts a Stream.
If I have an ImageSource, how do I convert it to something acceptable to the property? Note that I need to be able to do this fast, in memory.
In the examples in the source code I can only find examples of loading images from file:
var image = LoadFileToMemory(new System.Uri(#"test.png", System.UriKind.RelativeOrAbsolute).ToString());
this.ModelMaterial = new PhongMaterial
{
AmbientColor = Colors.Gray.ToColor4(),
DiffuseColor = Colors.White.ToColor4(),
SpecularColor = Colors.White.ToColor4(),
SpecularShininess = 100f,
DiffuseAlphaMap = image,
DiffuseMap = LoadFileToMemory(new System.Uri(#"TextureCheckerboard2.dds", System.UriKind.RelativeOrAbsolute).ToString()),
NormalMap = LoadFileToMemory(new System.Uri(#"TextureCheckerboard2_dot3.dds", System.UriKind.RelativeOrAbsolute).ToString()),
};
LoadFileToMemory simply takes the bytes from a file and returns it as a MemoryStream.
By ImageSource you mean a BitmapSource or DrawingImage? ImageSource is the abstract base class for both of them.
If you have a BitmapSource you can convert it to a MemoryStream using:
private Stream BitmapSourceToStream(BitmapSource writeBmp)
{
Stream stream = new MemoryStream();
//BitmapEncoder enc = new PngBitmapEncoder();
//BitmapEncoder enc = new JpegBitmapEncoder();
BitmapEncoder enc = new BmpBitmapEncoder();
enc.Frames.Add(BitmapFrame.Create(writeBmp));
enc.Save(stream);
return stream;
}
I have the following two functions to convert bytes to image and display on Image in WPF
private JpegBitmapDecoder ConvertBytestoImageStream(byte[] imageData)
{
Stream imageStreamSource = new MemoryStream(imageData);
JpegBitmapDecoder decoder = new JpegBitmapDecoder(imageStreamSource, BitmapCreateOptions.PreservePixelFormat, BitmapCacheOption.Default);
BitmapSource bitmapSource = decoder.Frames[0];
return decoder;
}
The above code does not work at all. I always get the exception that "No imaging component found" Image is not displayed.
private MemoryStream ConvertBytestoImageStream(int CameraId, byte[] ImageData, int imgWidth, int imgHeight, DateTime detectTime)
{
GCHandle gch = GCHandle.Alloc(ImageData, GCHandleType.Pinned);
int stride = 4 * ((24 * imgWidth + 31) / 32);
Bitmap bmp = new Bitmap(imgWidth, imgHeight, stride, PixelFormat.Format24bppRgb, gch.AddrOfPinnedObject());
MemoryStream ms = new MemoryStream();
bmp.Save(ms, ImageFormat.Jpeg);
gch.Free();
return ms;
}
This function works, but is very slow. I wish to optimize my code.
Your ConvertBytestoImageStream works fine for me if i pass it a JPEG buffer. There are however a few things that could be improved. Depending on whether you really want to return a decoder or a bitmap, the method could be written this way:
private BitmapDecoder ConvertBytesToDecoder(byte[] buffer)
{
using (MemoryStream stream = new MemoryStream(buffer))
{
return BitmapDecoder.Create(stream,
BitmapCreateOptions.PreservePixelFormat,
BitmapCacheOption.OnLoad); // enables closing the stream immediately
}
}
or this way:
private ImageSource ConvertBytesToImage(byte[] buffer)
{
using (MemoryStream stream = new MemoryStream(buffer))
{
BitmapDecoder decoder = BitmapDecoder.Create(stream,
BitmapCreateOptions.PreservePixelFormat,
BitmapCacheOption.OnLoad); // enables closing the stream immediately
return decoder.Frames[0];
}
}
Note that instead of using JpegBitmapDecoder this code utilizes a static factory method of the abstract base class BitmapDecoder which automatically selects the proper decoder for the provided data stream. Hence this code can be used for all image formats supported by WPF.
Note also that the Stream object is used inside a using block which takes care of disposing it when it is no longer needed. BitmapCacheOption.OnLoad ensures that the whole stream is loaded into the decoder and can be closed afterwards.
I need to read a jpg file and latyer display it in an Image controll.
The following works perfectly:
imgTwo.Source = FetchImage(#"C:\Image075.jpg");
public BitmapSource FetchImage(string URLlink)
{
JpegBitmapDecoder decoder = null;
BitmapSource bitmapSource = null;
decoder = new JpegBitmapDecoder(new Uri(URLlink, UriKind.Absolute), BitmapCreateOptions.PreservePixelFormat, BitmapCacheOption.OnLoad);
bitmapSource = decoder.Frames[0];
bitmapSource.Freeze();
return bitmapSource;
}
My problem is that I need to keep this image in a database as Byte[] (varbinary(MAX) and read it from there, not directly from a file as the above does.
So I need to either have a Byte[] as input to this function instead of a URLlink string, or save the BitmapSource as Byte[]. How do I do that?
JpegBitmapDecoder has a second constructor that accepts a Stream. Just pass in a MemoryStream containing your byte[]:
using(var stream = new MemoryStream(yourByteArray))
{
decoder = new JpegBitmapDecoder(stream,
BitmapCreateOptions.PreservePixelFormat,
BitmapCacheOption.OnLoad);
}
I've been trying to Serialize and Deserialize BitmapImages. I've been using methods which supposedly works which I found in this thread: error in my byte[] to WPF BitmapImage conversion?
Just to iterate what is going on, here is part of my Serialization code:
using (MemoryStream ms = new MemoryStream())
{
// This is a BitmapImage fetched from a dictionary.
BitmapImage image = kvp.Value;
PngBitmapEncoder encoder = new PngBitmapEncoder();
encoder.Frames.Add(BitmapFrame.Create(image));
encoder.Save(ms);
byte[] buffer = ms.GetBuffer();
// Here I'm adding the byte[] array to SerializationInfo
info.AddValue((int)kvp.Key + "", buffer);
}
And here is the deserialization code:
// While iterating over SerializationInfo in the deserialization
// constructor I pull the byte[] array out of an
// SerializationEntry
using (MemoryStream ms = new MemoryStream(entry.Value as byte[]))
{
ms.Position = 0;
BitmapImage image = new BitmapImage();
image.BeginInit();
image.StreamSource = ms;
image.EndInit();
// Adding the timeframe-key and image back into the dictionary
CapturedTrades.Add(timeframe, image);
}
Also, I'm not sure if it matters but earlier when I populated my dictionary I encoded Bitmaps with PngBitmapEncoder to get them into BitmapImages. So not sure if double-encoding has something to do with it. Here's the method that does that:
// Just to clarify this is done before the BitmapImages are added to the
// dictionary that they are stored in above.
private BitmapImage BitmapConverter(Bitmap image)
{
using (MemoryStream ms = new MemoryStream())
{
image.Save(ms, System.Drawing.Imaging.ImageFormat.Png);
BitmapImage bImg = new BitmapImage();
bImg.BeginInit();
bImg.StreamSource = new MemoryStream(ms.ToArray());
bImg.EndInit();
ms.Close();
return bImg;
}
}
So the problem is, serialization and deserialization works fine. No errors, and the dictionary has entries with what seems to be BitmapImages, however their width/height and
some other properties are all set to '0' when I look at them in debugging-mode. And of course, nothing is shown when I try to display the images.
So any ideas as to why they aren't properly deserialized?
Thanks!
1) You should not dispose MemoryStream, used from image initializing. Remove using in this line
using (MemoryStream ms = new MemoryStream(entry.Value as byte[]))
2) After
encoder.Save(ms);
Try adding
ms.Seek(SeekOrigin.Begin, 0);
ms.ToArray();
I am having some trouble creating a BitmapImage from a MemoryStream from png and gif bytes obtained from a web request. The bytes seem to be downloaded fine and the BitmapImage object is created without issue however the image is not actually rendering on my UI. The problem only occurs when the downloaded image is of type png or gif (works fine for jpeg).
Here is code that demonstrates the problem:
var webResponse = webRequest.GetResponse();
var stream = webResponse.GetResponseStream();
if (stream.CanRead)
{
Byte[] buffer = new Byte[webResponse.ContentLength];
stream.Read(buffer, 0, buffer.Length);
var byteStream = new System.IO.MemoryStream(buffer);
BitmapImage bi = new BitmapImage();
bi.BeginInit();
bi.DecodePixelWidth = 30;
bi.StreamSource = byteStream;
bi.EndInit();
byteStream.Close();
stream.Close();
return bi;
}
To test that the web request was correctly obtaining the bytes I tried the following which saves the bytes to a file on disk and then loads the image using a UriSource rather than a StreamSource and it works for all image types:
var webResponse = webRequest.GetResponse();
var stream = webResponse.GetResponseStream();
if (stream.CanRead)
{
Byte[] buffer = new Byte[webResponse.ContentLength];
stream.Read(buffer, 0, buffer.Length);
string fName = "c:\\" + ((Uri)value).Segments.Last();
System.IO.File.WriteAllBytes(fName, buffer);
BitmapImage bi = new BitmapImage();
bi.BeginInit();
bi.DecodePixelWidth = 30;
bi.UriSource = new Uri(fName);
bi.EndInit();
stream.Close();
return bi;
}
Anyone got any light to shine?
Add bi.CacheOption = BitmapCacheOption.OnLoad directly after your .BeginInit():
BitmapImage bi = new BitmapImage();
bi.BeginInit();
bi.CacheOption = BitmapCacheOption.OnLoad;
...
Without this, BitmapImage uses lazy initialization by default and stream will be closed by then. In first example you try to read image from possibly garbage-collected closed or even disposed MemoryStream. Second example uses file, which is still available.
Also, don't write
var byteStream = new System.IO.MemoryStream(buffer);
better
using (MemoryStream byteStream = new MemoryStream(buffer))
{
...
}
I'm using this code:
public static BitmapImage GetBitmapImage(byte[] imageBytes)
{
var bitmapImage = new BitmapImage();
bitmapImage.BeginInit();
bitmapImage.StreamSource = new MemoryStream(imageBytes);
bitmapImage.EndInit();
return bitmapImage;
}
May be you should delete this line:
bi.DecodePixelWidth = 30;