I'm using a class library that generates a large ImageSource, > 3000x3750 pixels. I would like to convert this ImageSource to BitmapImage so that I can take advantage of DecodePixelWidth or DecodePixelHeight instead of resizing it everytime this image is generated.
I need to display this image for the user first, and most of the users have a screen resolution of 1024x768, I'm binding this ImageSource to an Image control for this, but it can be noticed how "heavy" it is.
How can I do this? Or what is the best solution for this case?
thanks!
Try doing:
myBitmapImage = myImageSource as BitmapImage;
That works well.
The BitmapImage type inherits BitmapSource and ultimately ImageSource (both of which are abstract classes). You need to check what the actual type of your object is, i.e. check object.GetType().Name. If you're in luck, it may actually be returning a BitmapSource object and you will simply need to cast it to that type before being able to use it as such.
Related
My WPF UI is keeping all of the images I use in memory. Below is the relevant retention graph. Using the ANTS Memory Profiler 8.7, I have established that none of my code is holding onto any these objects. I have written code so that multiple request for the same image create only one image, but that leaves me with the problem that there are enough images within my application to crash it when they are all loaded simultaneously. I turned off this code when I ran this memory profile. I need to flush these images. I have even resorted to manually calling GC.Collect which did not reduce the memory used. Something is holding these images and it is not my code.
Here is the code for how I expose the BitmapImage to then be bound to Image.Source. This does not contain my image-to-path dictionary caching service that is now turned off.
public BitmapImage Image
{
get
{
var image = new BitmapImage();
image.BeginInit();
image.UriSource = a_url;
image.CreateOptions = BitmapCreateOptions.IgnoreImageCache;
image.EndInit();
image.Freeze();
return image;
}
}
// The XAML
<Image Source="{Binding Image, Mode=OneWay}"/>
NOT A DUPLICATE
I have determined that the BitmapImage is being held on to and have explicitly invoked GC.Collect which did nothing. The problem is not the GC. I also always Freeze my BitmapImage objects when I create them in code. This is not my first time around.
I can see from the object graph that you have a class called ImageAnimationController, which is holding a reference to the Image control that uses your BitmapImage as its source by a DependencyPropertyDescriptor. The ImageAnimationController uses the DependencyPropertyDescriptor to subscribe to change notifications of the Image control's Source DependencyProperty. When the ImageAnimationController class is disposed it will unsubscribe from the DependencyPropertyDescriptor notifications.
It looks like this ImageAnimationController class is a component of an open source library called WPF Animated GIF. I can't see how you are using this library as you have not included the source, but I imagine that somewhere you have either something like this:
ImageBehavior.SetAnimatedSource(img, image);
Or this:
<Image gif:ImageBehavior.AnimatedSource="{Binding Image}" />
I am not familiar with this library or your code, but I imagine that you will need to ensure that this attached behaviour is correctly detached and disposed of.
Each WPF Image Control has RenderTransform Property that sets Scale, Skew, Rotate and many more Transformation to Images. After Calling RenderTransform Property, How to get Rendered Image into the BitmapImage or RenderTargetBitmap Class or Any other class?
This is my Code:
Dim InImage As New BitmapImage(New Uri("My Image Path"))
Dim TG As New TransformGroup
TG.Children.Add(New RotateTransform(190))
Dim MyImg As New Image
MyImg.Source = InImage
MyImg.RenderTransform = TG
'Here i need get Transformed Image into a BitmapImage or RenderTargetBitmap Variable or Any other class variable.
It's a pity that TransformedBitmap does not support rotation with angle other than any multiple of 90 degs (that means we can only rotate 90, 180, 270, ...). Thinking about which objects we can put in a bitmap and apply some Transform? Well we have DrawingGroup, DrawingVisual, ImageBrush, UIElement and via DrawingContext.
Using DrawingGroup, we have to put in an ImageDrawing and apply the transform via the Transform property of the DrawingGroup. Then we have to use a DrawingImage, set the Drawing property to the DrawingGroup.
Using DrawingVisual, we have to open a DrawingContext, use the DrawImage method after pushing some transform. Then we may have to use RenderTargetBitmap by passing the DrawingVisual in the Render method.
Using UIElement (like your idea about using Image control as the medium), we have to render the image on the UIElement. So an Image control suits this best. Every UIElement has a Transform property allowing us to add whatever transform. At last we also have to use a RenderTargetBitmap by passing the UIElement in the Render method.
Using ImageBrush, we have to set the ImageSource property to a BitmapImage. Then we can use the Transform or RelativeTransform property to apply some transform. After that we have to use a DrawingImage. Create a simple GeometryDrawing using the ImageBrush as its Brush, and a RectangleGeometry as its Geometry. Finally we just need to set this GeometryDrawing to the Drawing property of the DrawingImage. The output is the DrawingImage. I would like to use this approach to write the code here:
Dim InImage As New BitmapImage(New Uri("My Image Path"))
Dim ImgBrush As New ImageBrush(InImage)
ImgBrush.Viewport = New Rect(0.1,0.1,0.8,0.8)
ImgBrush.ViewportUnits = BrushMappingMode.RelativeToBoundingBox
Dim Rotating As New RotateTransform(190)
Rotating.CenterX = 0.5
Rotating.CenterY = 0.5
ImgBrush.RelativeTransform = Rotating
Dim ImgSize As New Rect(0,0,300,400)
Dim DrawImage As New DrawingImage()
DrawImage.Drawing = New GeometryDrawing(ImgBrush, null, ImgSize)
Note about the "My Image Path". I've found out that using a Relative image would not work if you don't have any Image folder at the same level with the built exe file. If you don't want to deploy some image folder together with your application, you can add your image as a Resource. To refer to an image added as a Resource in code behind, you have to use a special kind of path:
pack://application:,,,/Your_Relative_Image_Path
Note that to be sure your image is added as a Resource, try right clicking on the image (under the Projects treeview), select Properties in the popup menu, then look into the Build Action field, it should be Resource.
Also note about the ImgBrush.Viewport, setting it appropriately will prevent the image from being cut off (that's because the transformed image is rotated). It depends on the ImgSize and how much degree you rotate.
I may be missing something about the fundamentals of WPF design, but I was wondering why many properties on WPF controls are exposed as the type 'Object'?
For example, MenuItem.Icon is an Object, and so is MenuItem.ToolTip. As a near first time user, this was very confusing to me (it felt like I was using a dynamic programming language, having no idea whether setting ToolTip to a String type would even work or not). Moreover, I tried to set the Icon to a 'System.Drawing.Icon' and I get an ArgumentException of "Argument 'picture' must be a picture that can be used as a Icon." Shouldn't the property be typed so it can at least describe what in the world you're supposed to give it?
Honestly, my guess as to the reason is because you cannot implement an interface on a type you did not create (without creating a wrapper), but that's just a guess.
Thanks very much for your answers and insights!
The main reason in my opinion is that since an Object is the "ultimate base class of all classes in the .Net Framework". This gives you flexibility, in WPF you are not limited to a predefined type. Wpf is different and has a learning curve, but it does give you a lot more options to create a product that looks good.
i.e.
You can assign a TextBox to a ToolTip:
TextBox tb = new TextBox();
tb.Text = "Hello World";
this.ToolTip = tb;
a Bitmap
BitmapImage myBitmapImage = new BitmapImage(new Uri((#"C:\Temp\20100706.jpg")));
Image image = new Image();
image.Source = myBitmapImage;
this.ToolTip = image;
and assigning a Image to a MenuItem
BitmapImage myBitmapImage = new BitmapImage(new Uri((#"C:\Temp\20100706.jpg")));
Image image = new Image();
image.Source = myBitmapImage;
menuItem1.Icon = image;
Consider the ToolTip for example. A ToolTip is a ContentControl, which can contain any type of CLR (Common Language Runtime) object (such as a string or a DateTime object) or a UIElement object (such as a Rectangle or a Panel). This enables you to add rich content to controls such as Button and CheckBox.
For this reason, elements such as ToolTip are exposed as Object, that is the root of the type hierarchy (with resulting ease of use, flexibility and clarity of the code).
Imagine these properties were typed as UIElements (or some other WPF specific object). How would you add objects to your controls that were not UIElements?
You would have to provide a wrapper derived from a WPF object that exposes the information you require. Most of the time the wrapper would simply call ToString() of the object being wrapped. Seeing as most types you will be using provide a good enough default implementation of ToString() it makes sense to just call this instead of making the developer write wrappers for everything.
Second, imagine if they were typed as some interface. What if you want to communicate something that this interface can't? The only options are (a) the developer lives with the limitations of the framework or (b) Microsoft updates the interface and breaks all existing code which has already been written.
Also consider if you are using a pattern like MVVM. The current design means your view models can expose properties that are not tied to WPF in any way which ultimately makes your code more reusable across different technologies.
Finally, remember that there is a difference between the object that represents the property and they way that WPF renders that information. E.G. if you use a primitive type such as System.String, WPF will create a textblock and set the text property to the result of ToString(). This allows a very clean separation between the data that is displayed by the UI and they way the information is rendered by the UI.
Take a simple class that represents a menu item, for example:
public class MenuItem
{
public string Text { get; set; }
public bool IsChecked { get; set; }
public bool IsEnabled { get; set; }
}
This type only exposes data about the menu item and has no information about how this information should be rendered. In fact, apart from the name of the class (MenuItem) this is not even specific to a menu item and the same data could be used in another UI control such as a checked listbox with no changes required. If the class exposed WPF specific user interface elements then the information would need to be adapted by another type for each different user interface control.
I have an image (embedded resource) that i can get access to and form an Image object from. I actually can get the Image object or the Stream of bits the represent the image. However I want to sue that image programaticly to be a background image.
So how do I set the ImageSource on the ImageBrush to an AcutalImage (PNG)?
I think the MSDN documentation says it all:
http://msdn.microsoft.com/en-us/library/system.windows.media.imagebrush.imagesource%28VS.95%29.aspx
You can either set the source as a URI in XAML, or use code behind to set it to an ImageSource object created from a stream or a Uri, e.g.
_imageBrush.ImageSource = new BitmapImage(new Uri("http://someurl.com/images/myimage.png"));
Cheers, Alex
EDIT: If your image is a ressource, you can use the ressource url syntax:
"/{AssemblyName};component/{RelativePath}"
For example:
<ImageBrush ImageSource="/MyApplication.Resources;component/Images/image1.png" />
I have a project which requires be to convert an in memory System.Drawing.Bitmap into an in memory BitmapImage so I can bind the BitmapImage to an Image control via XAML. The problem I am running into is during the conversion the original bitmap gets shrunk and is very blurry.
This is very bad because the original bitmap is a bar code and I need this bar code to stay readable. Is there anything I can do to preserve the integrity of my bitmap? Or is it possible to bind a System.Drawing.Bitmap to an WPF Image control without first saving the bitmap and using a URI?
Also can anyone explain to me the difference between all these image formats? It seems as if there are a ton of them, they reside in numerous namespaces and it is a pain to convert between them.
EDIT.....
public static BitmapImage GetBitmapImage(Bitmap bmp)
{
MemoryStream ms = new MemoryStream();
bmp.Save(ms, ImageFormat.Bmp);
BitmapImage bmpI = new BitmapImage();
bmpI.BeginInit();
bmpI.StreamSource = ms;
bmpI.EndInit();
ms.Close();
ms.Dispose();
return bmpI;
}
Have you tried different bitmap scaling modes?
For example:
Image RenderOptions.BitmapScalingMode="HighQuality" ...
In my opinion, the easiest way to get rid of all those burdens is to create a user control, then put a
WindowsFormsHost
on to that control. After that you put a windows forms image to the host, and in the underlying code of the user control, you can create a dependency property to bind data and update changes to the image control.
Cheers.