Develop Reference

After Encode to base64 image rotated by 90 degres

in my app I'm uploading images to server. I encode image from my WP 8.1 and send it to server. Sending and receiving work well but I have problem with image. I don't know why but whem I uploaded the image photographed on portrait after decoding is this image rotated by 90 degrees. Landscapes images are good, but portrait are rotated. Here is my encode and decode code
Encode:
private async Task<string> StorageFileToBase64(StorageFile file)
{
string Base64String = "";
if (file != null)
{
IRandomAccessStream fileStream = await file.OpenAsync(FileAccessMode.Read);
var reader = new DataReader(fileStream.GetInputStreamAt(0));
await reader.LoadAsync((uint)fileStream.Size);
byte[] byteArray = new byte[fileStream.Size];
reader.ReadBytes(byteArray);
Base64String = Convert.ToBase64String(byteArray);
}
return Base64String;
}
Decode image on server
public void ShowImg(string b64)
{
byte[] imageBytes = Convert.FromBase64String(b64);
// Convert byte[] to Image
var ms = new MemoryStream(imageBytes, 0, imageBytes.Length);
Image image = Image.FromStream(ms, true);
f.pictureBox1.Image = image;
}

string startExpression = "data:image/png;base64,";
using (var ms = new MemoryStream())
{
ms.Flush();
System.Drawing.Image imageIn = System.Drawing.Image.FromFile(fileName);
ms.Position = 0;
imageIn.RotateFlip(System.Drawing.RotateFlipType.Rotate90FlipX);
imageIn.Save(ms, System.Drawing.Imaging.ImageFormat.Png);
var bytes= ms.ToArray();
string fileBase = Convert.ToBase64String(bytes);
var base64= startExpression + fileBase;
imageIn.Dispose();
ms.Dispose();
}

Dispalying pictures from database in xaml

I write image in local database.
MemoryStream stream = new MemoryStream();
WriteableBitmap mywbq = new WriteableBitmap(bmp);
mywbq.SaveJpeg(stream, mywbq.PixelWidth, mywbq.PixelHeight, 0, 95);
byte[] imagearray = stream.ToArray();
stream.Close();
db._contacts.InsertOnSubmit(new MyContactsList {ItemImage = imagearray });
db.SubmitChanges();
And I want this picture display in xaml.
How it's impossible?
I use it source
But this class doesn't work

Simple as that:
byte[] yourImageBytesFromDatabase = ......;
MemoryStream ms = new MemoryStream();
ms.Write(yourImageBytesFromDatabase, 0, yourImageBytesFromDatabase.Length);
BitmapImage src = new BitmapImage();
src.SetSource(ms);

Convert bitmap to ImageSource give NullReference exception

I've got WCF service to send image as a stream to client app.
My client app gets the stream :
Stream imageStream = client.GetImage();
When I use this code:
imageStream.CopyTo(stream);
int size = (int)stream.Length;
stream.Seek(0, SeekOrigin.Begin);
BitmapFrame bf = BitmapFrame.Create(stream,
BitmapCreateOptions.None,
BitmapCacheOption.OnLoad);
cam_img.Source = bf;
It work's fine but I need apply some filters to image before assign to source.
So I need bitmap. First, I convert Stream imageStream to byte array and then I use some code I find on forums:
byte[] tab_img;
using (var memoryStream = new MemoryStream())
{
imageStream.CopyTo(memoryStream);
tab_img= memoryStream.ToArray();
}
Bitmap bm;
using (MemoryStream mStream = new MemoryStream())
{
mStream.Write (tab_img, 0, tab_img.Length);
mStream.Seek(0, SeekOrigin.Begin);
bm = new Bitmap(mStream);
Grayscale filter = new Grayscale(0.2125, 0.7154, 0.0721);
Bitmap bm_post = filter.Apply(bm);
ImageSourceConverter c = new ImageSourceConverter();
object source = new ImageSourceConverter().ConvertFrom(bm_post);
ImageSource is1 = (ImageSource)source;
cam_img.Source = is1;
}
but I still get NullReferenceException in line
object source = new ImageSourceConverter().ConvertFrom(bm_post);

upload photo to server

I am using this code for upload photo:
MemoryStream photoStream = new MemoryStream();
e.ChosenPhoto.CopyTo(photoStream);
photoStream.Position = 0;
byte[] buf = photoStream.ToArray();
string str = Convert.ToBase64String(buf);
string fileBase64 = HttpUtility.UrlEncode(str);
// Send fileBase64 to server
The server then decode the base64 string and name it "test.jpt".
the problem is that paint doesn't open the image uploaded on my server.
Why ?

i think your base64 string is incorrect. I have written this code, here it is, it works:
BitmapImage a = new BitmapImage();
a.SetSource(e.ChosenPhoto);
WriteableBitmap wb = new WriteableBitmap(a);
MemoryStream ms = new MemoryStream();
wb.SaveJpeg(ms, a.PixelWidth, a.PixelHeight, 0, 50); //50 is a quality of a photo
imageBytes = ms.ToArray();
base64 = System.Convert.ToBase64String(imageBytes);

Bitmap to Base64String

i am trying to convert a bitmap to a base64 string.i can convert to from string to bitmap...but it seems like there is a problem when converting from bitmap to string.I was hoping you guys could give me a hand
public static string BitmapToString(BitmapImage image)
{
Stream stream = image.StreamSource ;
Byte[] buffer = null;
if (stream != null && stream.Length > 0)
{
using (BinaryReader br = new BinaryReader(stream))
{
buffer = br.ReadBytes((Int32)stream.Length);
}
}
return Convert.ToBase64String(buffer);
}
it gets a ArgumentNullException was unhandled
Value cannot be null.
Parameter name: inArray
when returning Convert.ToBase64String(buffer)
Help?

Try this alternative:
public string BitmapToBase64(BitmapImage bi)
{
MemoryStream ms = new MemoryStream();
PngBitmapEncoder encoder = new PngBitmapEncoder();
encoder.Frames.Add(BitmapFrame.Create(bi));
encoder.Save(ms);
byte[] bitmapdata = ms.ToArray();
return Convert.ToBase64String(bitmapdata);
}
In your solution, it is not necessary that StreamSource will always have value if it is loaded using a Uri.

First of all, it is necessary to save BitmapImage data into memory using some bitmap encoder (PngBitmapEncoder for example).
public static byte[] EncodeImage(BitmapImage bitmapImage)
{
using (MemoryStream memoryStream = new MemoryStream())
{
BitmapEncoder encoder = new PngBitmapEncoder();
encoder.Frames.Add(BitmapFrame.Create(bitmapImage));
encoder.Save(memoryStream);
return memoryStream.ToArray();
}
}
Then just encode the binary data with Base64-encoding.
const string filePath = #"...";
const string outFilePath = #"...";
const string outBase64FilePath = #"...";
// Constuct test BitmapImage instance.
BitmapImage bitmapImage = new BitmapImage();
bitmapImage.BeginInit();
bitmapImage.StreamSource = File.OpenRead(filePath);
bitmapImage.CacheOption = BitmapCacheOption.OnLoad;
bitmapImage.EndInit();
// Convert BitmapImage to byte array.
byte[] imageData = EncodeImage(bitmapImage);
File.WriteAllBytes(outFilePath, imageData);
// Encode with Base64.
string base64String = Convert.ToBase64String(imageData);
// Write to file (for example).
File.WriteAllText(outBase64FilePath, base64String);