Develop Reference

Converting ImageSource to String on C# WPF

ESRI Symbology library is slow and sometimes take longer time than expected.
I wish to serialize a selected range of ImageSource to a cache, string in the memory or file.
I have searched the web but not much on ImageSource.
An interesting thing I have found is "ImageSourceValueSerializer".
Being a 3 months old baby in WPF, I am not so sure how to go about this.
here's how I got the ImageSource:
MultilayerPointSymbol multiLayerSym = await result.GetSymbolAsync() as MultilayerPointSymbol;
RuntimeImage swatch = await multiLayerSym.CreateSwatchAsync();
ImageSource symbolImage = await swatch.ToImageSourceAsync();
Tested Clemen's, the routine:
MultilayerPointSymbol multiLayerSym = await result.GetSymbolAsync() as MultilayerPointSymbol;
RuntimeImage swatch = await multiLayerSym.CreateSwatchAsync();
ImageSource symbolImage = await swatch.ToImageSourceAsync();
byte[] b = ImageSourceBinary(symbolImage);
ImageSource test = BinaryImageSource(b);
In the class:
private byte[] ImageSourceBinary(ImageSource imageSrc)
{
if (imageSrc is BitmapSource bitmapSource)
{
PngBitmapEncoder encoder = new PngBitmapEncoder();
encoder.Frames.Add(BitmapFrame.Create(bitmapSource));
using (MemoryStream stream = new MemoryStream())
{
encoder.Save(stream);
return stream.ToArray();
}
}
return null;
}
private ImageSource BinaryImageSource(byte[] bytes)
{
using (MemoryStream stream = new MemoryStream(bytes))
{
PngBitmapDecoder decoder = new PngBitmapDecoder(stream, BitmapCreateOptions.IgnoreImageCache, BitmapCacheOption.Default);
BitmapFrame bf = decoder.Frames[0];
if (bf is ImageSource imagesource)
return imagesource;
return null;
}
}
The outcome, no image! :(

Check if the ImageSource is a BitmapSource and encode the BitmapSource by one of the BitmapEncoders. Encode into a MemoryStream or a FileStream.
private byte[] ImageSourceToByteArray(ImageSource imageSrc)
{
if (symbolImage is BitmapSource bitmapSource)
{
var encoder = new PngBitmapEncoder();
encoder.Frames.Add(BitmapFrame.Create(bitmapSource));
using (var stream = new MemoryStream())
{
encoder.Save(stream);
return stream.ToArray();
}
}
return null;
}
In order to decode an image from a byte array, do not explictly use a specific BitmapDecoder. Better rely on automatic decoder selection, like shown below. It is also important to set BitmapCacheOption.OnLoad when the stream is closed right after decoding.
private ImageSource ByteArrayToImageSource(byte[] bytes)
{
using (var stream = new MemoryStream(bytes))
{
return BitmapFrame.Create(
stream, BitmapCreateOptions.None, BitmapCacheOption.OnLoad);
}
}

WPF C# Image Source

I'm pretty new to displaying images in WPF forms, and i'm having trouble when it comes to converting and assigning an Image source for my GUI.
System.Drawing.Image testImg = ImageServer.DownloadCharacterImage(charID, ImageServer.ImageSize.Size128px);
byte[] barr = imgToByteArray(testImg);
CharImage.Source = ByteToImage(barr);
public byte[] imgToByteArray(System.Drawing.Image testImg)
{
using (MemoryStream ms = new MemoryStream())
{
testImg.Save(ms,System.Drawing.Imaging.ImageFormat.Jpeg);
return ms.ToArray();
}
}
public System.Drawing.Image ByteToImage(byte[] barr)
{
MemoryStream ms = new MemoryStream(barr);
System.Drawing.Image returnImage = System.Drawing.Image.FromStream(ms);
return returnImage;
}
So i take in an image (JPEG) from the EVE Online C# API Library and then try to convert it to a byte array and back to a proper image. However i always get this error: "Cannot Implicitly convert type 'System.Drawing.Image' to 'System.Windows.Media.ImageSource'" I'm completely dumbfounded on how to solve this.

One possible solution is to save the image files (for example, .jpg) as WPF embedded resource and then use the following code snippet to get BitmapImage:
Listing 1. Get BitmapImage from EmbeddedResource
private string GetAssemblyName()
{
try { return Assembly.GetExecutingAssembly().FullName.Split(',')[0]; }
catch { throw; }
}
private BitmapImage GetEmbeddedBitmapImage(string pathImageFileEmbedded)
{
try
{
// compose full path to embedded resource file
string _fullPath = String.Concat(String.Concat(GetAssemblyName(), "."), pathImageFileEmbedded);
BitmapImage _bmpImage = new BitmapImage();
_bmpImage.BeginInit();
_bmpImage.StreamSource = Assembly.GetExecutingAssembly().GetManifestResourceStream(_fullPath);
_bmpImage.EndInit();
return _bmpImage;
}
catch { throw; }
finally { }
}
Correspondingly, set the Source property of the WPF Image control (for example, Image1) to that BitmapImage returned by function:
Image1.Source = GetEmbeddedBitmapImage(_strEmbeddedPath);
Note: you should reference the following:
using System.Windows.Media.Imaging;
using System.Reflection;
Another possible solution is to get the BitmapImage from image file using Uri object as shown in the following code snippet (Listing 2):
Listing 2. Get BitmapImage from File (use Uri)
private BitmapImage GetBitmapImageFromFile(string ImagePath)
{
Uri BitmapUri;
StreamResourceInfo BitmapStreamSourceInfo;
try
{
// Convert stream to Image.
BitmapImage bi = new BitmapImage();
BitmapUri = new Uri(ImagePath, UriKind.Relative);
BitmapStreamSourceInfo = Application.GetResourceStream(BitmapUri);
bi.BeginInit();
bi.StreamSource = BitmapStreamSourceInfo.Stream;
bi.EndInit();
return bi;
}
catch { throw; }
}
Hope this may help.

System.Drawing.Image is WinForms, not WPF. Your ByteToImage method should return BitmapSource instead.
The probably easiest way to create a BitmapSource from a byte array is BitmapFrame.Create:
public BitmapSource ByteArrayToImage(byte[] buffer)
{
using (var stream = new MemoryStream(buffer))
{
return BitmapFrame.Create(stream,
BitmapCreateOptions.None, BitmapCacheOption.OnLoad);
}
}
You would assign the return value of the above method to the Source property of an Image control:
image.Source = ByteArrayToImage(barr);

How can I decode a byte array using a JpegBitmapDecoder

I cannot decode images back from their encoded form as a (Jpeg) byte array retrieved from my database to be used as image sources for my WPF application.
The code I am using to encode them as a Jpeg byte array is as follows:
public byte[] bytesFromBitmap(BitmapImage bit)
{
byte[] data;
JpegBitmapEncoder encoder = new JpegBitmapEncoder();
encoder.Frames.Add(BitmapFrame.Create(bit));
using (MemoryStream ms = new MemoryStream())
{
encoder.Save(ms);
data = ms.ToArray();
}
return data;
}
This is taking my Image taken directly from a webpage and assigned to an Image control like so:
var img = new BitmapImage(new Uri(entity.Image.ImageSrc)); //the entity has been saved in my DB, having been parsed from html
pbImage.Source = img;
This works just fine, I encode the BitmapImage and it saves just fine. But when I retrieve it from the DB and try to display it in another window, I cannot get it to work after trying every example I can see online - all either render nothing, or a black box or a visual mess not at all similar to the image I encoded.
Neither of the following have worked for me:
public BitmapSource GetBMImage(byte[] data)
{
using (var ms = new MemoryStream(data))
{
JpegBitmapDecoder decoder = new JpegBitmapDecoder(ms, BitmapCreateOptions.PreservePixelFormat, BitmapCacheOption.Default);
BitmapSource frame = decoder.Frames[0];
return frame;
}
}
public static BitmapImage ImageFromBytes(byte[] imageData)
{
if (imageData == null)
{
return null;
}
else
{
var image = new BitmapImage();
using (var mem = new MemoryStream())
{
mem.Position = 0;
image.BeginInit();
image.CreateOptions = BitmapCreateOptions.PreservePixelFormat;
image.CacheOption = BitmapCacheOption.OnLoad;
image.UriSource = null;
image.StreamSource = mem;
image.EndInit();
}
image.Freeze();
return image;
}
} //this throws a 'No imaging component suitable to complete this operation was found' exception
Among other uses of memory streams and decoders I just can't get this to work - can anyone help?

How to create BitmapImage from a bmp file byte array?

In my wpf application I get a byte array of a bmp file.
I want to create a new System.Windows.Media.Imaging.BitmapImage.
I created MemoryStream from the byte array, but it doesn't work with SetSource.
Any suggestions ?

Add reference:
using System.IO;
Use the following code.
MemoryStream ms = new MemoryStream(imageArray);
Image image = Image.FromStream(ms);
For WPF
public static BitmapImage GetBitmapImage(byte[] imageArray)
{
using (var stream = new MemoryStream(imageArray))
{
var bitmapImage = new BitmapImage();
bitmapImage.BeginInit();
bitmapImage.CacheOption = BitmapCacheOption.OnLoad;
bitmapImage.StreamSource = stream;
bitmapImage.EndInit();
return bitmapImage;
}
}

Convert base64 string to image in C# on Windows Phone

I have a base64 string and I want convert that to an image and set the Source of an Image control to the result of that.
Normally I would do that using Image.FromStream, similar to this:
Image img;
byte[] fileBytes = Convert.FromBase64String(imageString);
using(MemoryStream ms = new MemoryStream())
{
ms.Write(fileBytes, 0, fileBytes.Length);
img = Image.FromStream(ms);
}
However, the Image.FromStream method does not exist on Windows Phone, and a casual search only turns up results that depend on that method.

You can use a method like this:
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;
}
}
Add an image to your XAML, such as this:
<Image x:Name="myWonderfulImage" />
You can then set the source, like this:
myWonderfulImage.Source = base64image(yourBase64string);