BitMapImage to byte and reverse

Question

Since two days I try to manage my images in a WPF application but I have errors and errors errors, ...

The image is show in a System.Windows.Control.Image. For this reason I try to work with variable BitMapImage.

Now I have the error : "Impossible to access close stream" and I can not find a solution.

I have created two function for convert :

public static BitmapImage ConvertToBitMapImage(byte[] bytes)
    {
        if (bytes == null || bytes.Length == 0) return null;
        var image = new BitmapImage();
        using (var mem = new MemoryStream(bytes))
        {
            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;
    }

    public static 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;
    }

In my object I have a property :

        public BitmapImage MiniatureApp
    {
        get
        {
            if (IMAGES != null)
                _MiniatureApp = Tools.BinaryImageConverter.ConvertToBitMapImage(IMAGES.IMAGE);
            return _MiniatureApp;
        }
        set
        {
            if (this.IMAGES != null)
                this.IMAGES.IMAGE = Tools.BinaryImageConverter.ImageToByte((BitmapImage)value);
            else
            {
                IMAGES img = new IMAGES();
                img.NOM = "";
                img.IMAGE = Tools.BinaryImageConverter.ImageToByte((BitmapImage)value);
                this.IMAGES = img;
            }
            NotifyPropertyChanged();
        }
    }

And in my main I do this :

FileStream fs = new FileStream(pathImage, FileMode.Open, FileAccess.Read);
byte[] data = new byte[fs.Length];
fs.Read(data, 0, System.Convert.ToInt32(fs.Length));
fs.Close();
VMAppareil.VMApp.CurrentAppareil.MiniatureApp = Tools.BinaryImageConverter.ConvertToBitMapImage(data);

Exist a solution for my problem or exist a best way to do this ?

Gobelet.

Your ImageToByte method is not ok, because StreamSource is closed when you try to access it. This is what BitmapCacheOption.OnLoad does. This answer explains how save BitmapImage to byte array: http://stackoverflow.com/a/6597746/5574010 — Anton Danylov, Mar 06 '16 at 20:58
Is there any reason at all why you are storing images as byte arrays (in IMAGES.IMAGE)? — Clemens, Mar 06 '16 at 21:08

score 1 · Answer 1 · edited May 23 '17 at 12:13

1

You can fix your solution replacing the ImageToByte method with the following (borrowed from https://stackoverflow.com/a/6597746/5574010)

public static byte[] ImageToByte(BitmapImage imageSource)
{
    var encoder = new JpegBitmapEncoder();
    encoder.Frames.Add(BitmapFrame.Create(imageSource));

    using (var ms = new MemoryStream())
    {
        encoder.Save(ms);
        return ms.ToArray();
    }
}

Your previous solution did not work because the ConvertToBitMapImage method close the stream that you assign to image.StreamSource as soon as your code exit the unit statement. When you call the ImageToByte method as part of the MiniatureApp setter the StreamSource will be close and you get an error.

edited May 23 '17 at 12:13

Community

1
1

answered Mar 06 '16 at 20:46

Andrea Angella

341
2
7

My image is load from a database. I have no other choice to load my Image from bytes – Gobelet Mar 07 '16 at 11:44
Ok. Your main seems to load the bytes from a file on disk but maybe that was just an example. – Andrea Angella Mar 07 '16 at 17:46
It's for my example, I load first time from disk and convert it to bytes and try to load from bytes but it doesn't work :p – Gobelet Mar 07 '16 at 18:18
Edited my response with what I think is the solution to your problem. – Andrea Angella Mar 07 '16 at 22:06

vapcguy · Accepted Answer · 2016-10-12T21:05:36.530

I'm not really sure what you're doing with the getter-setter.

For getting a byte array from a file, I would have this:

public static byte[] FileToByteArray(string fileName)
{
    byte[] fileData = null;

    using (FileStream fs = new File.OpenRead(fileName)) 
    { 
        var binaryReader = new BinaryReader(fs); 
        fileData = binaryReader.ReadBytes((int)fs.Length); 
    }
    return fileData;
}

And once you have the bytes from that function, you can use ConvertToBitMapImage() and assign that to the Image.Source, like this:

byte[] bytes = FileToByteArray(fileName);
YourImage.Source = ConvertToBitMapImage(bytes);

I'm not sure why you would need to convert a BitmapImage into bytes, but you should be able to call your function directly for that:

BitmapImage bImg = new BitmapImage();
bImg.Source = ConvertToBitMapImage(bytes);
byte[] bytes = ImageToByte(bImg);  // these should be the same bytes as went in

Set it up like this and step through the code to see where it snags. It's possible the bytes might need encoding when you grab it in ImageToByte().

But also, you don't just then set the byte[] directly to the IMAGES or this.IMAGES.IMAGE, because that isn't an Image object, it's a byte[]. Without knowing what your IMAGES model construct looks like with its property types, it's a little vague to know what is being set to what and why, but this seems like a bad idea to over-complicate what you should just do with function calls as it is needed, without a getter-setter and an IMAGES model in the way.

BitMapImage to byte and reverse

2 Answers2

Linked