C# Removing transparancy from BitmapImage - c#

i'm using a .png as a BitmapImage. The image is being used as a texture on a 3d model.
There is some transparancy in the image which i want to remove.
How do i remove it? (as efficiently as possible, using VisualBrush or System.Drawing.Image is not an option.)
BitmapImage bi = new BitmapImage();
bi.BeginInit();
bi.UriSource = new Uri(fullPath, UriKind.Absolute);
bi.EndInit();
bi.Freeze();
ImageBrush br = new ImageBrush(bi) { Stretch = Stretch.Fill };
DiffuseMaterial mat = new DiffuseMaterial(br);

Related

Bitmap to image conversion shows a white image only

I do have some problems to display an image (uEye-Cam) in a wpf-Image form. The displayed image is completely white. Below is my used code:
//Get Cam Bitmap Image
var cam = new uEye.Camera();
cam.Init();
cam.Memory.Allocate();
cam.Acquisition.Capture(uEye.Defines.DeviceParameter.DontWait);
Int32 s32MemId;
cam.Memory.GetActive(out s32MemId);
cam.Memory.Lock(s32MemId);
Bitmap bitmap;
cam.Memory.ToBitmap(s32MemId, out bitmap);
//WPF Image control
var image1 = new System.Windows.Controls.Image();
//convert System.Drawing.Image to WPF image
var bmp = new System.Drawing.Bitmap(bitmap);
IntPtr hBitmap = bmp.GetHbitmap();
System.Windows.Media.ImageSource wpfBitmap = System.Windows.Interop.Imaging.CreateBitmapSourceFromHBitmap(hBitmap, IntPtr.Zero, Int32Rect.Empty, BitmapSizeOptions.FromEmptyOptions());
image1.Source = wpfBitmap;
image1.Stretch = System.Windows.Media.Stretch.UniformToFill;
image1.Visibility = Visibility.Visible;
DeleteObject(hBitmap);
Is there anything wrong with the image1 properties maybe or..?
Thanks
WPF bitmap to image conversion shows a black image only
I've had good results with converting every new frame to a bitmap as in the question:
Bitmap bmp;
cam.Memory.ToBitmap(s32MemId, out bmp);
And then converting this to a BitmapImage using:
BitmapImage bitmapImage = null;
using (System.IO.MemoryStream memory = new System.IO.MemoryStream())
{
bitmapImage = new BitmapImage();
bmp.Save(memory, System.Drawing.Imaging.ImageFormat.Bmp);
memory.Position = 0;
bitmapImage.BeginInit();
bitmapImage.StreamSource = memory;
bitmapImage.CacheOption = BitmapCacheOption.OnLoad;
bitmapImage.EndInit();
}
And then locking and freezing (as in How do you pass a BitmapImage from a background thread to the UI thread in WPF?) the BitmapImage to set it as the source of the Image control using:
Object tempLock = new Object();
BitmapImage lastBitmapImage = null;
lock (tempLock)
{
lastBitmapImage = bitmapImage.Clone();
}
lastBitmapImage.Freeze();
Finally, the BitmapImage is set as the souce of the Image control with:
this.Dispatcher.Invoke(new Action(() =>
{
imageDisplay.Source = lastBitmapImage;
}));

Unable to display Image created from Base64 BitmapImage

I want to display an Image in a StackPanel from a base64 string but it's not working correctly.
string base64encodedImage = el.Value;
byte[] imageData = Convert.FromBase64String(base64encodedImage);
Image imageSection = new Image();
BitmapImage image = new BitmapImage();
using (MemoryStream memStream = new MemoryStream(imageData))
{
image.BeginInit();
image.StreamSource = memStream;
image.EndInit();
}
imageSection.Source = image;
panel.Children.Add(imageSection);
Example Base64 Image:
iVBORw0KGgoAAAANSUhEUgAAAAUAAAAFCAYAAACNbyblAAAAHElEQVQI12P4//8/w38GIAXDIBKE0DHxgljNBAAO9TXL0Y4OHwAAAABJRU5ErkJggg==
The BitmapImage gets a width and height, the Image however does not and nothing is displayed, what am I doing wrong?
Refer to this post to find the correct way to get the BitmapImage from byte array.

Fill WPF rectangle with Image

I created new WPF control, added a Rectangle to it, and everyhing works alright, its drawn like it should be. But I just cant paint the rectangle with an actual Image.
BitmapImage bi = GetImage();
ImageBrush imgBrush= new ImageBrush(bi);
this.rectangle.Fill = imgBrush;
But this code just makes the rectangle transparent, except the stroke.
This is the GetImage() method:
BitmapImage bi;
using (MemoryStream ms = new MemoryStream())
{
bi = new BitmapImage();
bi.CacheOption = BitmapCacheOption.OnLoad;
texture.SaveAsPng(ms, texture.Width, texture.Height);
ms.Seek(0, SeekOrigin.Begin);
bi.BeginInit();
bi.StreamSource = ms;
bi.EndInit();
ms.Close();
}
return bi;
texture is an Texture2D class, that is made before this code.
If I return Bitmap insted of BitmapImage here and then save that Bitmap the picture is drawn correctly.
Thank you for your help
This is the correct way to convert Bitmap to BitmapImage:
using(MemoryStream memory = new MemoryStream())
{
bitmap.Save(memory, ImageFormat.Png);
memory.Position = 0;
BitmapImage bitmapImage = new BitmapImage();
bitmapImage.BeginInit();
bitmapImage.StreamSource = memory;
bitmapImage.CacheOption = BitmapCacheOption.OnLoad;
bitmapImage.EndInit();
}
Thanks to "Pawel Lesnikowski", he posted the anwser in the following topic:
Load a WPF BitmapImage from a System.Drawing.Bitmap

BitmapImage PixelWidth and PixelHeight property from UriSource

I have this:
BitmapImage bi = new BitmapImage();
bi.CreateOptions = BitmapCreateOptions.None;
bi.UriSource = new Uri(url, UriKind.RelativeOrAbsolute);
,where url =www.xyz.com/abc.jpg
My question is "How to get the bi.PixelWidth and bi.PixelHeight?" because both are coming as zero. I want to resize big images in to thumbnails.
I have tried this one.
I am fairly new to WP7 development. I cam across this issue and is actually still trying to figure out how to do this.
But I could get it to work with WritableBitmap like so :
Uri uri = new Uri("/image.jpg", UriKind.Relative);
BitmapImage bitmapImage = new BitmapImage();
bitmapImage.CreateOptions = BitmapCreateOptions.None;
bitmapImage.UriSource = uri;
WriteableBitmap img = new WriteableBitmap(bitmapImage);
using (MemoryStream ms = new MemoryStream())
{
// write an image into the stream
Extensions.SaveJpeg(img, ms, img.PixelWidth, img.PixelHeight, 0, 100);
byte[] byteArray = ms.ToArray();
}

Rendering an image at runtime in WPF

I have posted several questions related to this problem I am having and I am starting to believe this cannot be done. Here is the back story.
I have an ASP.NET application from which I want to generate a .png image. This .png image needs to be constructed from either XAML or a WPF Visual Tree. Because of this, I must generate the .png image in an STA thread. Everything works fine until my XAML/WPF Visual Tree includes an Image (as in a System.Windows.Controls.Image). My .png file gets generated correctly except the Image element does not show the referenced picture. The referenced picture is located at a remote URL. No errors or exceptions are thrown.
How do I create a .png image from some XAML/WPF Visual Tree that includes a System.Windows.Controls.Image element? The resulting .png must include the picture referenced in the Image element. I have tried the following code in a variety of ways:
string address = "http://imgtops.sourceforge.net/bakeoff/o-png24.png";
WebClient webClient = new WebClient();
byte[] imageContent = webClient.DownloadData(address);
Image image = new Image();
using (MemoryStream memoryStream = new MemoryStream(imageContent))
{
BitmapImage imageSource = new BitmapImage();
imageSource.BeginInit();
imageSource.StreamSource = memoryStream;
imageSource.EndInit();
image.Source = imageSource;
}
// Set the size
image.Height = 200;
image.Width = 300;
// Position the Image within a Canvas
image.SetValue(Canvas.TopProperty, 1.0);
image.SetValue(Canvas.LeftProperty, 1.0);
Canvas canvas = new Canvas();
canvas.Height = 200;
canvas.Width = 300;
canvas.Background = new SolidColorBrush(Colors.Purple);
canvas.Children.Add(image);
// Create the area
Size availableSize = new Size(300, 200);
frameworkElement.Measure(availableSize);
frameworkElement.Arrange(new Rect(availableSize));
// Convert the WPF representation to a PNG file
BitmapSource bitmap = RenderToBitmap(frameworkElement);
PngBitmapEncoder encoder = new PngBitmapEncoder();
encoder.Frames.Add(BitmapFrame.Create(bitmap));
// Generate the .png
FileStream fileStream = new FileStream(filename, FileMode.Create);
encoder.Save(fileStream);
public BitmapSource RenderToBitmap(FrameworkElement target)
{
int actualWidth = 300;
int actualHeight = 200;
Rect boundary = VisualTreeHelper.GetDescendantBounds(target);
RenderTargetBitmap renderBitmap = new RenderTargetBitmap(actualWidth, actualHeight, 96, 96, PixelFormats.Pbgra32);
DrawingVisual drawingVisual = new DrawingVisual();
using (DrawingContext context = drawingVisual.RenderOpen())
{
VisualBrush visualBrush = new VisualBrush(target);
context.DrawRectangle(visualBrush, null, new Rect(new Point(), boundary.Size));
}
renderBitmap.Render(drawingVisual);
return renderBitmap;
}
Thank you for your help.
You are rendering the output bitmap correctly, it is just the input bitmap you are screwwing up :).
BitmapImage requires access to the StreamSource property until it fires the DownloadCompleted event, but the 'using' block Dispose()s of the MemoryStream before it has a chance! You could simply unwrap the MemoryStream from the using block and let the GC handle it (if you do, I would recommend setting the BitmapImage.CacheOption to BitmapCacheOption.None, so it uses the stream directly, rather than a copy), but I would use the UriSource property and wait for the DownloadComplete event before rendering.

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