We Keep Coding

BitmapImage -> Bitmap -> Mat -> Bitmap ->BitmapImage Convert

I'm developing a kind of real-time video chatting and also trying to make a binary image using OpenCV. I'm working on C# WPF and I have to draw images on Canvas. This means I need 'BitmapImage' to draw the screen. But I have to use 'Mat' to make a binary image.
So I tried many solutions found from StackOverflow but never worked for me.
Below is my code.
Mat tempMat = new Mat();
Bitmap tempImage = BitmapImage2Bitmap(tempOriginal);
tempMat = BitmapConverter.ToMat(tempImage);
Converting BitmapImage to Bitmap first, and then convert Bitmap to Mat.
After that, make image binary. Below is the code.
Mat hsv = new Mat();
Mat binary = new Mat();
Cv2.CvtColor(tempMat, hsv, ColorConversionCodes.BGR2HSV);
Cv2.InRange(hsv, new Scalar(minH, minS, minV), new Scalar(maxH, maxS, maxV), binary);
tempMat = binary.Clone();
binary.Release();
hsv.Release();
After this operation, convert the mat back to Bitmap and BitmapImage again.
Below is the code.
tempImage = BitmapConverter.ToBitmap(tempMat);
BitmapImage resultBitmap = Bitmap2BitmapImage(tempImage);
ipWindow.ipView.ImageSource = resultBitmap;
I searched a lot and tried several solutions to change Bitmap to BitmapImage and vice versa.
But never worked. Below codes are solutions I tried.
I'm new to C# and also WPF, so I have no idea how to solve this problem.
Thanks for reading this long question.
Solution1. BitmapImage -> Bitmap
private Bitmap BitmapImage2Bitmap(BitmapImage bitmapImage){
using (MemoryStream outStream = new MemoryStream())
{
BitmapEncoder enc = new BmpBitmapEncoder();
enc.Frames.Add(BitmapFrame.Create(bitmapImage));
enc.Save(outStream);
Bitmap bitmap = new Bitmap(outStream);
outStream.Close();
return new Bitmap(bitmap);
}
}
Solution1. Bitmap -> BitmapImage
private BitmapImage Bitmap2BitmapImage(Bitmap bitmap){
BitmapSource i = Imaging.CreateBitmapSourceFromHBitmap(
bitmap.GetHbitmap(),
IntPtr.Zero,
Int32Rect.Empty,
BitmapSizeOptions.FromEmptyOptions());
return (BitmapImage)i;
}
Solution2. Bitmap -> BitmapImage
private BitmapImage Bitmap2BitmapImage(Bitmap inputBitmap){
Bitmap bitmap = new Bitmap(inputBitmap.Width, inputBitmap.Height, System.Drawing.Imaging.PixelFormat.Format32bppArgb);
MemoryStream ms = new MemoryStream();
bitmap.Save(ms, ImageFormat.Bmp);
var bi = new BitmapImage();
bi.BeginInit();
bi.StreamSource = ms;
bi.CacheOption = BitmapCacheOption.OnLoad;
bi.EndInit();
return bi;
}
Solution3. Bitmap -> BitmapImage
private BitmapImage Bitmap2BitmapImage(Bitmap inputBitmap){
using (var memory = new MemoryStream())
{
inputBitmap.Save(memory, ImageFormat.Png);
memory.Position = 0;
BitmapImage bitmapImage = new BitmapImage();
bitmapImage.BeginInit();
bitmapImage.StreamSource = memory;
bitmapImage.CacheOption = BitmapCacheOption.OnLoad;
bitmapImage.EndInit();
bitmapImage.Freeze();
return bitmapImage;
}
Solution4. Bitmap -> BitmapImage
private BitmapImage Bitmap2BitmapImage(Bitmap inputBitmap){
MemoryStream ms = new MemoryStream();
inputBitmap.Save(ms, ImageFormat.Bmp);
BitmapImage image = new BitmapImage();
image.BeginInit();
ms.Seek(0, SeekOrigin.Begin);
image.StreamSource = ms;
image.EndInit();
return image;
}

I solved. The problems were two.
One was OpenCvSharp and another was Bitmap to BitmapImage.
Actually OpenCvSharp problem was severe so I couldn't find proper solutions between above. But after I uninstall and reinstall the openCvSharp, I found out what solution works for me. The code is below.
private BitmapImage Bitmap2BitmapImage(Bitmap inputBitmap)
{
using (var memory = new MemoryStream())
{
inputBitmap.Save(memory, ImageFormat.Png);
memory.Position = 0;
BitmapImage bitmapImage = new BitmapImage();
bitmapImage.BeginInit();
bitmapImage.StreamSource = memory;
bitmapImage.CacheOption = BitmapCacheOption.OnLoad;
bitmapImage.EndInit();
bitmapImage.Freeze();
return bitmapImage;
}
}

Image Control not showing the webcam frames captured using OpenCVsharp

I have Written the Code below in my XAML code behind to show webcame frames Received as Mat with Opencvsharp VideoCapture.Read() method in my Image Control named View.
Mat mat = new Mat();
VideoCapture videoCapture = new VideoCapture(2);
while (true)
{
videoCapture.Read(mat);
viewer.Source = mat.ToBitmapImage();
if (btn_stop.IsPressed)
{
break;
}
}
videoCapture.Release();
As u can see I used a converter to convert form Mat to BitmapImage so I can use it as image Source of my control. here are the Converters I used:
static class Converters
{
public static BitmapImage ToBitmapImage(this Bitmap bitmap)
{
BitmapImage bi = new BitmapImage();
MemoryStream ms = new MemoryStream();
bi.BeginInit();
bitmap.Save(ms, ImageFormat.Bmp);
ms.Seek(0, SeekOrigin.Begin);
bi.StreamSource = ms;
bi.EndInit();
bi.Freeze();
return bi;
}
public static BitmapImage ToBitmapImage(this Mat mat)
{
return BitmapConverter.ToBitmap(mat).ToBitmapImage();
}
}
Simply this code shows nothing in my image control and the app is freezed. I know that this code is generating too much garbage and I can't do anything about it. Any ideas about my problem? i Also changed my code with the instructions given in this link like below:
viewer.Source = (BitmapSource)new ImageSourceConverter().ConvertFrom(mat.ToBytes());
and also these converters:
public static BitmapImage ToBitmapImage(this Mat mat)
{
BitmapImage image = new BitmapImage();
image.BeginInit();
image.StreamSource = new System.IO.MemoryStream(mat.ToBytes());
image.EndInit();
return image;
}
public static BitmapImage ToBitmapImage(this Mat mat)
{
using (var ms = new System.IO.MemoryStream(mat.ToBytes()))
{
var image = new BitmapImage();
image.BeginInit();
image.CacheOption = BitmapCacheOption.OnLoad;
image.StreamSource = ms;
image.EndInit();
return image;
}
}
none of these worked for me.

heres the answer according to Clemens's comment:
Simply insantiate a DispatcherTimer object in MainWindow's constructor and use the Tick event to update the UI:
DispatcherTimer Timer = new DispatcherTimer();
Timer.Tick += Timer_Tick;
Timer.Interval = TimeSpan.FromMilliseconds(30);
Timer.Start();
private void Timer_Tick(object sender, EventArgs e)
{
if (videoCapture.Read(frame))
{
view.Source = OpenCvSharp.Extensions.BitmapSourceConverter.ToBitmapSource(frame);
}
}

WPF Byte Array to ImageSource without using MemoryStream

I have an application that creates WPF Image controls on-the-fly to display images from a SQL Server database table. The panels that display the controls get replaced frequently. I use MemoryStreams to allow the controls to access the byte arrays loaded from the database. I cannot close these streams as long as the Image controls are displayed and still have the images displayed. My concern is that these streams will be left open until the Garbage Collector gets around to disposing of the Image controls and hopefully closing the streams too. I will probably end up just making sure that I close the streams or dispose of the Image controls before the panels are replaced but would like to know if there is an issue with leaving these streams open and if there is a way around this.
Here's the code that I am using.
public class ImageToSql
{
private static OpenFileDialog _openFileDialog = new OpenFileDialog();
static ImageToSql()
{
_openFileDialog = new OpenFileDialog();
_openFileDialog.AddExtension = true;
_openFileDialog.CheckFileExists = true;
_openFileDialog.DefaultExt = ".jpg";
_openFileDialog.Filter = "JPEG files (*.jpg)|*.jpg|All files (*.*)|*.*";
_openFileDialog.FilterIndex = 1;
_openFileDialog.Multiselect = false;
}
public static BitmapImage LoadImageFromFile(string caption)
{
BitmapImage bi = new BitmapImage();
_openFileDialog.Title = caption;
if (_openFileDialog.ShowDialog() == true)
{
bi.BeginInit();
bi.StreamSource = File.OpenRead(_openFileDialog.FileName);
bi.EndInit();
}
return bi;
}
public static int StoreImage(string connectionString, string sql, string imageParameterName, BitmapImage bitmapImage)
{
SqlConnection conn = new SqlConnection(connectionString);
try
{
conn.Open();
sql += ";SELECT ##IDENTITY";
using (SqlCommand cmd = new SqlCommand(sql, conn))
{
byte[] data = new byte[bitmapImage.StreamSource.Length];
bitmapImage.StreamSource.Seek(0, SeekOrigin.Begin);
bitmapImage.StreamSource.Read(data, 0, data.Length);
cmd.Parameters.Add(imageParameterName, System.Data.SqlDbType.VarBinary, -1).Value = data;
object obj = cmd.ExecuteScalar();
return Int32.Parse(obj.ToString());
}
}
finally
{
conn.Close();
}
}
public static BitmapImage RetrieveImage(string connectionString, string sql, string imageIDParameterName, int imageID)
{
BitmapImage bi = new BitmapImage();
SqlConnection conn = new SqlConnection(connectionString);
try
{
conn.Open();
using (SqlCommand cmd = new SqlCommand(sql, conn))
{
cmd.Parameters.Add(imageIDParameterName, System.Data.SqlDbType.Int).Value = imageID;
byte[] data = (byte[])cmd.ExecuteScalar();
MemoryStream ms = new MemoryStream(data);
ms.Seek(0, SeekOrigin.Begin);
bi.BeginInit();
bi.StreamSource = ms;
bi.EndInit();
}
}
finally
{
conn.Close();
}
return bi;
}
}
Below is how this code is called. "_fileImage" and "_sqlImage" are Image controls on my test Window. At one point, I was using a stream to read the file from disk in "LoadImageFromFile" and think I was able to close that stream while still displaying the image in the Image control. So, MemoryStream seems to be special somehow.
BitmapImage bi = ImageToSql.LoadImageFromFile("Select Image to Save");
_fileImage.Source = bi;
int imageID = ImageToSql.StoreImage(connString,
"INSERT INTO PV_Image (Description, Image) VALUES ('Some Image', #pImage)",
"#pImage", bi);
_sqlImage.Source = ImageToSql.RetrieveImage(connString,
"SELECT Image FROM PV_Image WHERE ImageID = #pImageID",
"#pImageID", imageID);

You can dispose the memory stream once it is used using the using pattern:
using (Stream stream = new MemoryStream(data))
{
BitmapImage image = new BitmapImage():
stream.Position = 0;
image.BeginInit();
image.CacheOption = BitmapCacheOption.OnLoad;
image.StreamSource = stream;
image.EndInit();
image.Freeze();
return image;
}

Converting Byte to Bitmap image

I am getting the byte in database but I cannot convert it to bitmap, I got an exception in Parameter. This is what I've done so far.
con.ConnectionString = MyConnectionString;
con.Open();
OdbcCommand cmds = new OdbcCommand("Select ID from try where kalabaw = 5", con);
OdbcDataAdapter da = new OdbcDataAdapter(cmds);
byte[] image = (byte[])cmds.ExecuteScalar();
TypeConverter tc = TypeDescriptor.GetConverter(typeof(Bitmap));
Bitmap bitmap = (Bitmap)tc.ConvertFrom(image);
pictureBox2.Image = bitmap;
con.Close();

I totally stole this answer from convert array of bytes to bitmapimage
public BitmapImage ToImage(byte[] array)
{
using (var ms = new System.IO.MemoryStream(array))
{
var image = new BitmapImage();
image.BeginInit();
image.CacheOption = BitmapCacheOption.OnLoad; // here
image.StreamSource = ms;
image.EndInit();
return image;
}
}

try the below. I expect it should work.
byte[] bytes = GetBytesArrayFromDatabase();
using (MemoryStream ms = new MemoryStream(bytes))
{
ms.Position = 0;
Bitmap obj = new Bitmap(ms);
// use the Bitmap object `obj` here
}

Converting BitmapImage to Bitmap and vice versa

I have BitmapImage in C#. I need to do operations on image. For example grayscaling, adding text on image, etc.
I have found function in stackoverflow for grayscaling which accepts Bitmap and returns Bitmap.
So I need to convert BitmapImage to Bitmap, do operation and convert back.
How can I do this? Is this best way?

There is no need to use foreign libraries.
Convert a BitmapImage to Bitmap:
private Bitmap BitmapImage2Bitmap(BitmapImage bitmapImage)
{
// BitmapImage bitmapImage = new BitmapImage(new Uri("../Images/test.png", UriKind.Relative));
using(MemoryStream outStream = new MemoryStream())
{
BitmapEncoder enc = new BmpBitmapEncoder();
enc.Frames.Add(BitmapFrame.Create(bitmapImage));
enc.Save(outStream);
System.Drawing.Bitmap bitmap = new System.Drawing.Bitmap(outStream);
return new Bitmap(bitmap);
}
}
To convert the Bitmap back to a BitmapImage:
[System.Runtime.InteropServices.DllImport("gdi32.dll")]
public static extern bool DeleteObject(IntPtr hObject);
private BitmapImage Bitmap2BitmapImage(Bitmap bitmap)
{
IntPtr hBitmap = bitmap.GetHbitmap();
BitmapImage retval;
try
{
retval = (BitmapImage)Imaging.CreateBitmapSourceFromHBitmap(
hBitmap,
IntPtr.Zero,
Int32Rect.Empty,
BitmapSizeOptions.FromEmptyOptions());
}
finally
{
DeleteObject(hBitmap);
}
return retval;
}

Here's an extension method for converting a Bitmap to BitmapImage.
public static BitmapImage ToBitmapImage(this Bitmap bitmap)
{
using (var memory = new MemoryStream())
{
bitmap.Save(memory, ImageFormat.Png);
memory.Position = 0;
var bitmapImage = new BitmapImage();
bitmapImage.BeginInit();
bitmapImage.StreamSource = memory;
bitmapImage.CacheOption = BitmapCacheOption.OnLoad;
bitmapImage.EndInit();
bitmapImage.Freeze();
return bitmapImage;
}
}

If you just need to go from BitmapImage to Bitmap it's quite easy,
private Bitmap BitmapImage2Bitmap(BitmapImage bitmapImage)
{
return new Bitmap(bitmapImage.StreamSource);
}

using System.Windows.Interop;
...
private BitmapImage Bitmap2BitmapImage(Bitmap bitmap)
{
BitmapSource i = Imaging.CreateBitmapSourceFromHBitmap(
bitmap.GetHbitmap(),
IntPtr.Zero,
Int32Rect.Empty,
BitmapSizeOptions.FromEmptyOptions());
return (BitmapImage)i;
}

I've just been trying to use the above in my code and I believe that there is a problem with the Bitmap2BitmapImage function (and possibly the other one as well).
using (MemoryStream ms = new MemoryStream())
Does the above line result in the stream being disposed of? Which means that the returned BitmapImage loses its content.
As I'm a WPF newbie I'm not sure that this is the correct technical explanation, but the code didn't work in my application until I removed the using directive.

Here the async version.
public static Task<BitmapSource> ToBitmapSourceAsync(this Bitmap bitmap)
{
return Task.Run(() =>
{
using (System.IO.MemoryStream memory = new System.IO.MemoryStream())
{
bitmap.Save(memory, ImageFormat.Png);
memory.Position = 0;
BitmapImage bitmapImage = new BitmapImage();
bitmapImage.BeginInit();
bitmapImage.StreamSource = memory;
bitmapImage.CacheOption = BitmapCacheOption.OnLoad;
bitmapImage.EndInit();
bitmapImage.Freeze();
return bitmapImage as BitmapSource;
}
});
}

Thanks Guillermo Hernandez, I created a variation of your code that works. I added the namespaces in this code for reference.
System.Reflection.Assembly theAsm = Assembly.LoadFrom("My.dll");
// Get a stream to the embedded resource
System.IO.Stream stream = theAsm.GetManifestResourceStream(#"picture.png");
// Here is the most important part:
System.Windows.Media.Imaging.BitmapImage bmi = new BitmapImage();
bmi.BeginInit();
bmi.StreamSource = stream;
bmi.EndInit();

This converts from System.Drawing.Bitmap to BitmapImage:
MemoryStream ms = new MemoryStream();
YOURBITMAP.Save(ms, System.Drawing.Imaging.ImageFormat.Bmp);
BitmapImage image = new BitmapImage();
image.BeginInit();
ms.Seek(0, SeekOrigin.Begin);
image.StreamSource = ms;
image.EndInit();