I am building an application to find dead pixels on the screen and I get a big problem that I can not solve by myself. My code uses to draw a rectangle on the screen at the point that user touch on.
My XAML code:
<Grid x:Name="mainGrid" Background="Gray">
<Canvas x:Name="myCanvas" Background="Purple" PointerMoved="digitizerGrid_PointerMoved" PointerReleased="digitizerGrid_PointerReleased">
<Grid x:Name="digitizerGrid" Visibility="Visible"/>
</Canvas>
</Grid>
and my c# code to handle event:
private void digitizerGrid_PointerMoved(object sender, PointerRoutedEventArgs e)
{
PointerPoint pt = e.GetCurrentPoint(myCanvas);
Point currentContactPt = pt.Position;
double x2 = currentContactPt.X;
double y2 = currentContactPt.Y;
Rectangle rect = new Rectangle()
{
Width = 50,
Height = 50,
StrokeThickness = 20.0,
Fill = new SolidColorBrush(Colors.Green)
};
Canvas.SetLeft(rect, x2);
Canvas.SetTop(rect, y2);
myCanvas.Children.Add(rect);
}
When I touch and fill all the screen like this:
I get the wrong result image below with black pixel blocks:
So I can not detect where is dead pixels. What I was wrong?
Thank in advance!
Related
I post this before and it was remove for being a duplicate. It is not. My problem is different then what that other people is doing. He is not doing zoom nor pan, and does not have a boarder.
I am using Stretch="Fill" to place my entire picture in the borders of an Image box. I am using a Border so that I can do Zoom and Pan. I am using the Canvas to draw rectangles around giving click areas. I want to map the left mouse click coordinates of the Canvas with zoom and pan back to the original image. here is my XAML code :
`
<Border x:Name="VideoPlayerBorder" ClipToBounds="True" Background="Gray" >
<Canvas x:Name="CanvasGridScreen" MouseLeftButtonDown="VideoPlayerSource_OnMouseLeftButtonDown" >
<Image x:Name="VideoPlayerSource" Opacity="1" RenderTransformOrigin="0.5,0.5" MouseLeftButtonUp="VideoPlayerSource_OnMouseLeftButtonUp" MouseWheel="VideoPlayerSource_OnMouseWheel" MouseMove="VideoPlayerSource_OnMouseMove" Width="{Binding Path=ActualWidth, ElementName=CanvasGridScreen}" Height="{Binding Path=ActualHeight, ElementName=CanvasGridScreen}" Stretch="Fill" >
</Image>
</Canvas>
`
here is my C# code:
`private void VideoPlayerSource_OnMouseLeftButtonDown(object sender, MouseButtonEventArgs e)
{
VideoPlayerSource.CaptureMouse();
var tt = (TranslateTransform)((TransformGroup)VideoPlayerSource.RenderTransform).Children.First(tr => tr is TranslateTransform);
start = e.GetPosition(VideoPlayerBorder);
origin = new Point(tt.X, tt.Y);
_stIR = start;
_stIR2 = start;
addRemoveItems(sender, e);
}
private void addRemoveItems(object sender, MouseButtonEventArgs e)
{
// this is the event that will check if we clicked on a rectangle or if we clicked on the canvas
// if we clicked on a rectangle then it will do the following
if (e.OriginalSource is Rectangle)
{
// if the click source is a rectangle then we will create a new rectangle
// and link it to the rectangle that sent the click event
Rectangle activeRec = (Rectangle)e.OriginalSource; // create the link between the sender rectangle
CanvasGridScreen.Children.Remove(activeRec); // find the rectangle and remove it from the canvas
}
// if we clicked on the canvas then we do the following
else
{
// generate a random colour and save it inside the custom brush variable
Custombrush = new SolidColorBrush(Color.FromRgb((byte)r.Next(1, 255),
(byte)r.Next(1, 255), (byte)r.Next(1, 233)));
// create a re rectangle and give it the following properties
// height and width 50 pixels
// border thickness 3 pixels, fill colour set to the custom brush created above
// border colour set to black
Rectangle newRec = new Rectangle
{
Width = 50,
Height = 50,
StrokeThickness = 3,
Fill = Custombrush,
Stroke = Brushes.Black
};
// once the rectangle is set we need to give a X and Y position for the new object
// we will calculate the mouse click location and add it there
Canvas.SetLeft(newRec, Mouse.GetPosition(CanvasGridScreen).X); // set the left position of rectangle to mouse X
Canvas.SetTop(newRec, Mouse.GetPosition(CanvasGridScreen).Y); // set the top position of rectangle to mouse Y
CanvasGridScreen.Children.Add(newRec); // add the new rectangle to the canvas
}
}
private void VideoPlayerSource_OnMouseWheel(object sender, MouseWheelEventArgs e)
{
TransformGroup transformGroup = (TransformGroup)VideoPlayerSource.RenderTransform;
ScaleTransform transform = (ScaleTransform)transformGroup.Children[0];
double zoom = e.Delta > 0 ? .2 : -.2;
double transformScaleX = Math.Round((transform.ScaleX + zoom), 2);
double transformScaleY = Math.Round((transform.ScaleY + zoom), 2);
if (transformScaleX <= 8.2 && transformScaleX >= 1)
{
transform.ScaleX = Math.Round(transform.ScaleX + zoom, 2);
transform.ScaleY = Math.Round(transform.ScaleY + zoom, 2);
zoomFactor2 = zoomFactor2 + zoom;
zoomFactor = zoomFactor2;
}
}
void PanMethod(MouseEventArgs e)
{
var tt = (TranslateTransform)((TransformGroup)VideoPlayerSource.RenderTransform).Children.First(tr => tr is TranslateTransform);
Vector v = start - e.GetPosition(VideoPlayerBorder);
if (zoomFactor > 1.0)
{
tt.X = origin.X - v.X;
tt.Y = origin.Y - v.Y;
}
}
is there a function that would give me this information ? is there a way of using TransformGroup or ScaleTransform to return the actual location in the picture that was clicked? again the Image with possible zoom and/or pan
Check out: https://learn.microsoft.com/en-us/dotnet/api/system.windows.media.visual.transformtovisual
The right way to translate coordinates back to the original pre-transforms control is to use the TransformToVisual helper. It's probably a good idea to do that regardless since transforms could be applied higher up in the stack.
In your case you want to call:
GeneralTransform transform = CanvasGridScreen.TransformToVisual(VideoPlayerSource);
Point normalizedPoint = transform.Transform(new Point(0, 0));
I have an app in C# WF, where user move and zoom image. I want to draw ellipse on Image control because ellipse remains in place, and don't moves when I modify the image.
View:
<Grid>
<Canvas Name="cavRoot" Opacity="1">
<Image Name="highresmap4" Source="highresmap4.png" Canvas.Left="0" Canvas.Top="0" Width="1473" Height="770">
</Image>
</Canvas>
</Grid>
Model:
class draw
{
public static void circle(double x, double y, int width, int height, Canvas cv)
{
Ellipse circle = new Ellipse()
{
Width = width,
Height = height,
Stroke = Brushes.Red,
StrokeThickness = 6
};
cv.Children.Add(circle);
circle.SetValue(Canvas.LeftProperty, (double)x);
circle.SetValue(Canvas.TopProperty, (double)y);
}
}
ViewModel:
draw.circle(x, y, 10, 10, cavRoot);
You could put the Image in a Grid and use the Margin property of the Ellipse to specify its position within the Image:
public static void circle(double x, double y, int width, int height, Panel cv)
{
Ellipse circle = new Ellipse()
{
Width = width,
Height = height,
Stroke = Brushes.Red,
StrokeThickness = 6,
Margin = new Thickness(x, y, 0, 0)
};
cv.Children.Add(circle);
}
XAML:
<Grid x:Name="theGrid">
<Image Name="highresmap4" Source="highresmap4.png" Width="1473" Height="770" />
</Grid>
I am looking for a way to draw a single point (with a color) on C# canvas.
In android I would do something like
paint.Color = Color.Rgb (10, 10, 10);
canvas.DrawPoint (x, y, paint);
So I thought that I would be able to find it in the Shape class, but it was not there. Am I missing something or there is no way to draw a single point?
In the second case, what is a recommended way of drawing a point? In HTML5 canvas there is a similar problem and people are drawing points using rectangles/circles.
P.S. a question with similar title Add Point to Canvas is not answering it and moving into "how to draw a shape".
I just ran in the same question for UWP, I finally decided to use an Ellipse:
int dotSize = 10;
Ellipse currentDot = new Ellipse();
currentDot.Stroke = new SolidColorBrush(Colors.Green);
currentDot.StrokeThickness = 3;
Canvas.SetZIndex(currentDot, 3);
currentDot.Height = dotSize;
currentDot.Width = dotSize;
currentDot.Fill = new SolidColorBrush(Colors.Green);
currentDot.Margin = new Thickness(100, 200, 0, 0); // Sets the position.
myGrid.Children.Add(currentDot);
What about a Polyline?
xaml:
<Grid x:Name="ContentPanel" Grid.Row="1" Margin="12,0,12,0">
<Canvas x:Name="canvas" Background="#00FFFFFF" MouseMove="Canvas_MouseMove">
<Polyline x:Name="polyline" Stroke="DarkGreen" StrokeThickness="3"/>
</Canvas>
</Grid>
c#:
private void ButtonBase_OnClick(object sender, RoutedEventArgs e)
{
polyline.Points.Add(new Point(0,0));
polyline.Points.Add(new Point(0, 1));
polyline.Points.Add(new Point(1, 0));
polyline.Points.Add(new Point(1, 1));
}
I have an Image viewer that displays an image. I want to draw a rectangle using the mouse over the image and get the x and y coordinates of the rectangle (X1, X2, Y1, and Y2). I will use these coordinates to create a search region and find the max and min values in an array that have the exact number of pixels as the image in both axes.
Can anyone guide me to a direction to start please?
You should use a canvas to display the image and draw a rectangle over it.
Example:
MainWindow.xaml:
<Window x:Class="CanvasRectangleSample.MainWindow"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
Title="MainWindow">
<Grid>
<Canvas x:Name="SampleImageCanvas"
MouseMove="SampleImageCanvas_MouseMove"
MouseDown="SampleImageCanvas_MouseDown"
Width="512" Height="389">
<Canvas.Background>
<!--Here you set the image to display -> You probably want to bind it to something. -->
<ImageBrush x:Name="SampleImage" Stretch="Uniform" ImageSource="C:\Users\Public\Pictures\Sample Pictures\Koala.jpg">
</ImageBrush>
</Canvas.Background>
<!-- Here you draw whatever you want on the canvas. -->
<!-- You'll probably want to bind its width and height to something too. -->
<Rectangle x:Name="ROI" Stroke="#FFF1133E" Width="50" Height="50"/>
</Canvas>
</Grid>
</Window>
MainWindow.xaml.cs:
using System.Windows;
using System.Windows.Input;
using System.Windows.Controls;
namespace CanvasRectangleSample
{
/// <summary>
/// Interaction logic for MainWindow.xaml
/// </summary>
public partial class MainWindow : Window
{
public MainWindow()
{
this.DataContext = this;
InitializeComponent();
}
// Handling the redrawing of the rectangle according to mouse location
private void SampleImageCanvas_MouseMove(object sender, MouseEventArgs e)
{
//get mouse location relative to the canvas
Point pt = e.MouseDevice.GetPosition(sender as Canvas);
//here you set the rectangle loction relative to the canvas
Canvas.SetLeft(ROI, pt.X - (int)(ROI.Width / 2));
Canvas.SetTop(ROI, pt.Y - (int)(ROI.Height / 2));
}
private void SampleImageCanvas_MouseDown(object sender, MouseButtonEventArgs e)
{
//Here you should handle saving the rectangle location
//don't forget to calculate the proportion between Canvas's size and real Image's size.
}
}
}
If you want you can limit the rectangle relocation to the canvas area with an if expression checking if the canvas area containes the mouse locaion
Thanks for the pointers and help:
Here is my finished code and it works. You place the mouse anywhere on the canvas hold mouse down and drag to create the rectangle. It could use some more improvement to drag and create the rectangle in any direction.
XAML:
<Canvas Name="ImageCanvas"
MouseMove="ImageCanvas_MouseMove"
MouseDown="ImageCanvas_MouseDown"
Height="240" Width="320"
HorizontalAlignment="Left"
Margin="87,514,0,0" VerticalAlignment="Top" MouseLeftButtonUp="ImageCanvas_MouseLeftButtonUp">
<Canvas.Background>
<ImageBrush x:Name="Image" Stretch="Uniform" ImageSource="C:\image.bmp">
</ImageBrush>
</Canvas.Background>
<Rectangle x:Name="ROI" Stroke="#FFF1133E" Width="20" Height="20" Canvas.Left="155" Canvas.Top="115" />
</Canvas>
Code:
double topLeftX = 0;
double topLeftY = 0;
double bottomRightX = 0;
double bottomrigthY = 0;
bool setRect = false;
private void ImageCanvas_MouseDown(object sender, MouseButtonEventArgs e)
{
topLeftY = topLeftX = bottomrigthY = bottomRightX = 0;
setRect = true;
System.Windows.Point pt = e.MouseDevice.GetPosition(sender as Canvas);
topLeftX = pt.X; topLeftY = pt.Y;
}
private void ImageCanvas_MouseMove(object sender, System.Windows.Input.MouseEventArgs e)
{
if (setRect == true)
{
//get mouse location relative to the canvas
System.Windows.Point pt = e.MouseDevice.GetPosition(sender as Canvas);
Canvas.SetLeft(ROI, topLeftX);
Canvas.SetTop(ROI, topLeftY);
ROI.Width = System.Math.Abs((int)(pt.X - topLeftX));
ROI.Height = System.Math.Abs((int)(pt.Y - topLeftY));
commandReturnTB.Text = (Convert.ToString(pt.X) + "," + Convert.ToString(pt.Y))+"\n";
}
}
private void ImageCanvas_MouseLeftButtonUp(object sender, MouseButtonEventArgs e)
{
System.Windows.Point pt = e.MouseDevice.GetPosition(sender as Canvas);
bottomRightX = pt.X;
bottomrigthY = pt.Y;
ROI.Width = System.Math.Abs((int)(bottomRightX - topLeftX));
ROI.Height = System.Math.Abs((int)(bottomrigthY - topLeftY));
Canvas.SetLeft(ROI, topLeftX);
Canvas.SetTop(ROI, topLeftY);
setRect = false;
commandReturnTB.Text = topLeftX + "," + topLeftY + "--" + bottomRightX + "," + bottomrigthY;
}
Using the following XAML:
<Grid x:Name="grid" Background="LightBlue" ClipToBounds="True">
<Grid.RowDefinitions>
<RowDefinition Height="*" />
</Grid.RowDefinitions>
<Viewbox x:Name="imgViewbox" >
<InkCanvas Grid.Row="0" Name="inkCanvas" Background="Red" >
<Image Source="Images/pic.png" HorizontalAlignment="Left" x:Name="imgObject" VerticalAlignment="Top" />
<Label>Testing</Label>
</InkCanvas>
</Viewbox>
</Grid>
I am trying to rotate around the center of the image and also use the wheel mouse to zoom. I have set up this transform group and event:
public MainWindow() {
InitializeComponent();
DataContext = new MainWindowViewModel();
transformGroup = new TransformGroup();
scaleTransform = new ScaleTransform();
rotateTransform = new RotateTransform();
translateTransform = new TranslateTransform();
transformGroup.Children.Add(rotateTransform);
transformGroup.Children.Add(scaleTransform);
transformGroup.Children.Add(translateTransform);
imgViewbox.RenderTransform = transformGroup;
imgViewbox.MouseWheel += ImageViewboxMouseWheel;
}
Rotate is simple:
void Rotate(object sender, RoutedEventArgs e) {
//imgViewbox.RenderTransformOrigin = new Point(0.5,0.5);
rotateTransform.Angle += 90;
}
but zoom is doing all sorts of weird stuff jumping around the screen. The code for zoom is here:
void ImageViewboxMouseWheel(object sender, MouseWheelEventArgs e) {
//imgViewbox.RenderTransformOrigin = new Point(0, 0);
double zoomFactor = DefaultZoomFactor;
if (e.Delta <= 0) zoomFactor = 1.0 / DefaultZoomFactor;
// DoZoom requires both the logical and physical location of the mouse pointer
var physicalPoint = e.GetPosition(imgViewbox);
if (transformGroup.Inverse != null) {
DoZoom(zoomFactor, transformGroup.Inverse.Transform(physicalPoint), physicalPoint);
}
else {
throw new ArgumentException("Missing Inverse");
}
//Set the center point of the ScaleTransform object to the cursor location.
scaleTransform.CenterX = e.GetPosition(imgViewbox).X;
scaleTransform.CenterY = e.GetPosition(imgViewbox).Y;
Debug.WriteLine(string.Format("IVMW Center {0},{1}", scaleTransform.CenterX, scaleTransform.CenterY));
}
public void DoZoom(double deltaZoom, Point mousePosition, Point physicalPosition) {
double currentZoom = scaleTransform.ScaleX;
currentZoom *= deltaZoom;
translateTransform.X = -1*(mousePosition.X*currentZoom - physicalPosition.X);
translateTransform.Y = -1*(mousePosition.X*currentZoom - physicalPosition.Y);
scaleTransform.ScaleX = currentZoom;
scaleTransform.ScaleY = currentZoom;
}
I have removed as much as I can, animations and such. Hopefully leaving only the key parts. I believe that the major problem is the scaleTransform.Center[X|Y] as the numbers that are being returned are all over the quadrant even when I try to click exactly in the same location. The RenderTransformOrigin doesn't seem to make any difference with the Center position but I am aware that I need it to rotate around center.
What am I doing wrong?
You need to offset the jump you get from changing the ScaleTranform's CenterX/Y in the TranslateTransform, here is a snippet from a pan & zoom control i wrote:
private void This_MouseWheel(object sender, MouseWheelEventArgs e)
{
if (IsZoomEnabled)
{
Point cursorPos = e.GetPosition(this);
Point newCenter = _scaleT.Inverse.Transform(_translateT.Inverse.Transform(cursorPos));
Point oldCenter = new Point(_scaleT.CenterX, _scaleT.CenterY);
Vector oldToNewCenter = newCenter - oldCenter;
_scaleT.CenterX = newCenter.X;
_scaleT.CenterY = newCenter.Y;
_translateT.X += oldToNewCenter.X * (_scaleT.ScaleX - 1.0);
_translateT.Y += oldToNewCenter.Y * (_scaleT.ScaleY - 1.0);
...
Hopefully you can adapt this to your code. Where the new center is calculated you might need to take your RotateTransform into account.