Develop Reference

Saving bitmap from clipboard into png in wpf application

i needed to send bitmap into my chat application soo my idea was save it into a temporaty folder and from there upload it like my drag and drop image thats already working. but when it saves the bitmap in windows fileviewer i can see thumbnail but everywhere else its empty any idea where the problem could be or how to do this any better way? thanks in advance.
here is a video so you can better understand ^^ https://youtu.be/p0t2byTRN58
string temp = Directory.GetParent(Environment.GetFolderPath(Environment.SpecialFolder.ApplicationData)).FullName + #"\Luxray\" + #"\clipboardimg.png";
if (File.Exists(temp))
{
File.Delete(temp);
}
BitmapSource bmpSource = Clipboard.GetImage();
MemoryStream ms = new MemoryStream();
FileStream stream = new FileStream(temp, FileMode.Create);
BitmapEncoder encoder = new PngBitmapEncoder();
encoder.Frames.Add(BitmapFrame.Create(bmpSource));
encoder.Save(stream);
stream.Close();
this code runs right after if statment that checks if clipboard has bitmap inside and ctrl+v was pressed in the video it is after msgbox with "img sent" pops up.

What are you trying to achieve? if you're trying to save a clipboard image to file the below code works for me:
var img = System.Windows.Forms.Clipboard.GetImage();
img.Save(savePath, ImageFormat.Png);

Getting error from the inkcanvase base 64 string

Hello we are using InkCanvas control on the wpf page. And we are saving Base64String string in the database. See code
private void submitButtonsCommand_Event(object sender)
{
byte[] sigByte;
InkCanvas icSignature = sender as InkCanvas;
using (var memoryStream = new MemoryStream())
{
icSignature.Strokes.Save(memoryStream);
sigByte = memoryStream.ToArray();
}
ServiceCallReportSignatureModel.SigCustomerSignature = Convert.ToBase64String(sigByte);
UpdateRecord();
}
And when we are retrieving data from the database and converting into the FromBase64String and after that when we creating image then we are getting the error.
public Image LoadImage(base64string)
{
//data:image/gif;base64,
//this image is a single pixel (black)
byte[] bytes = Convert.FromBase64String(base64string);
Image image;
using (MemoryStream ms = new MemoryStream(bytes))
{
image = Image.FromStream(ms);
}
return image;
}
I don't know why this is occurring. Please help me find out the error.
Our base64 string is : "AIwBAwxIEEWfARsCAAb/RjURAACAPx8JEQAAAAAAAPA/Cmwsh/EgR4kP+Etw/ojDWG7NZ8OZQxBN5otEzmU1mk04I7DnATcLHomzzUbxw/h3Dtp16yhlTQ2UsoTQh+uE64XgjsN6Js2UZpAZmFpmaZTKzzKZ4ctFmw3Mlmm0Bw9h/DtpTPKu79CYgm+VJqA="
Actually we are taking signature from the ink canvas control and we want to display in the pdf when we need. So we want create image from the base 64 data but we are getting the error.

The StrokeCollection.Save(Stream) method does not save a bitmap. Instead,
The Save method saves the StrokeCollection as Ink Serialized Format (ISF).
You can restore the saved StrokeCollection by passing a Stream with the saved data to the StrokeCollection(Stream) constructor.

Converting a BitmapImage byte array to an Image byte array (WinRT -> WinForms)

I have 2 solutions in this project. A windows forms solution and a Windows 8.1 Tablet project.
This is what's supposed to happen:
User takes a picture using the tablet and uploads it to a MySQL database in the form of a byte array.
User starts up the windows forms application and loads the byte array from the MySQL database.
It then converts the byte array to an image which is placed in a picturebox.
I'm storing the byte array like this:
CameraCaptureUI dialog = new CameraCaptureUI();
dialog.PhotoSettings.Format = CameraCaptureUIPhotoFormat.Jpeg;
Size aspectRatio = new Size(16, 9);
dialog.PhotoSettings.CroppedAspectRatio = aspectRatio;
StorageFile file = await dialog.CaptureFileAsync(CameraCaptureUIMode.Photo);
if (file != null)
{
BitmapImage bitmapImage = new BitmapImage();
using (IRandomAccessStream fileStream = await file.OpenAsync(FileAccessMode.Read))
{
var readStream = fileStream.AsStreamForRead();
byte[] pixeBuffer = new byte[readStream.Length];
await readStream.ReadAsync(pixeBuffer, 0, pixeBuffer.Length);
}
The byte array is successfully stored in my database.
I'm running into a problem when converting the byte array into a WinForms Image.
This is my code:
using (var ms = new MemoryStream(bytes))
{
Image i = Image.FromStream(ms);
return i;
}
This gives me an invalid parameter exception.
I'm guessing it's something with the image format? I'm really new to streams though so I have no idea.
Any help is welcome!
PS: I know storing in the SQL database runs perfectly since I can store and load images perfectly using the WinForms application only.

Have you tried setting the position of the MemoryStream back to the beginning before trying to create the Image...
ms.Seek(0, SeekOrigin.Begin);

using (MemoryStream ms = new MemoryStream())
{
WriteableBitmap btmMap = new WriteableBitmap
(bitmapImage.PixelWidth, bitmapImage.PixelHeight);
return ms.ToArray();
}
Try it ,
it's working with me

Changing Bitmaps using c#

I was working on my college project where i was trying to change bit values of a Bitmap.
I am loading the bitmap to the memory stream, then extracting it to byte[] array. Now I was changing few central bits of this byte[] array and then converting it back to a bitmap image.
But i got a run time exception that "Invalid Bitmap".
Does a bitmap have some special format instead of simple bits???
Following is the code used by me:
MemoryStream mstream = new MemoryStream();
Bitmap b = new Bitmap(#"D:\my_pic.bmp");
b.Save(mstream, System.Drawing.Imaging.ImageFormat.Bmp);
byte[] ba = mstream.ToArray();
mstream.Close();
byte[] _Buffer = null;
System.IO.FileStream _FileStream = new System.IO.FileStream(_FileName, System.IO.FileMode.Open, System.IO.FileAccess.Read);
System.IO.BinaryReader _BinaryReader = new System.IO.BinaryReader(_FileStream);
long _TotalBytes = new System.IO.FileInfo(_FileName).Length;
_Buffer = _BinaryReader.ReadBytes((Int32)_TotalBytes);
// close file reader
_FileStream.Close();
_FileStream.Dispose();
_BinaryReader.Close();
int leng1 = ba.Length;
int leng2=_Buffer.Length;
for(i=(leng1)/2;i<leng1;i++)
{
for(j=0;j<leng2;j++)
{
ba[i]=_Buffer[j];
}
if(j==(leng2-1))
{
break;
}
}
TypeConverter tc = TypeDescriptor.GetConverter(typeof(Bitmap));
Bitmap bitmap1 = (Bitmap)tc.ConvertFrom(ba);

You must have your own goal to want to operate at this low level with a bitmap and that's fine. Unless you are performance bound it is way easier to do graphics at the graphics API level. Even if you are performance sensitive, other people have cut a path through the jungle already.
Back to the question. The BMP file format is simpler than some others but still comes in many varieties. Here is a detailed introduction to the gory details of the BMP format:
BMP file format
Now if you are just parsing your own BMP files and you know they are 32-bit RGB, and the header is going to be such-and-such a size which you can skip over, etc, then that might work for you. If you need to handle any old BMP it gets messy real fast which is why the libraries try to take care of everything for you.

Convert System.Drawing.Image to System.Windows.Controls.Image?

Is there a way in C# to do this conversion and back?
I have a WPF app which has a Image control. I'm trying to save the image in that control to a SQL Database.
In my Entity Model, the datatype of the picture column in my database is a byte[]. So I found a method to convert a System.Drawing.Image to a byte[] and back. But I haven't found a method to convert from System.Windows.Controls.Image to a byte[].
So that's why I now need to do the above conversion.

If you have a byte array that represents a file that WPF can decode (bmp, jpg, gif, png, tif, ico), you can do the following:
BitmapSource LoadImage(Byte[] imageData)
{
using (MemoryStream ms = new MemoryStream(imageData))
{
var decoder = BitmapDecoder.Create(ms,
BitmapCreateOptions.PreservePixelFormat, BitmapCacheOption.OnLoad);
return decoder.Frames[0];
}
}
Likewise, to convert it back, you can do the following:
byte[] SaveImage(BitmapSource bitmap)
{
using (MemoryStream ms = new MemoryStream())
{
var encoder = new BmpBitmapEncoder();
encoder.Frames.Add(BitmapFrame.Create(bitmap));
encoder.Save(ms);
return ms.GetBuffer();
}
}

Well, one is an image and one is a control that shows an image, so I don't think that there's a conversion between the two. But, you could set the Source of the ...Controls.Image to be your ...Drawing.Image.
Edit based on update
Does this do what you need - http://msdn.microsoft.com/en-us/library/ms233764%28VS.100%29.aspx