Develop Reference

How to cut slices from a very large image faster using C#?

I have images that could be as big as 20000x20000 pixels in height and width. (Not more than 50 MB). Loading such images into a picture box using C# is very slow and when I need to slice this thing into 200x200 pixels images, it is very slow (few images per second). My current application works fine but very slow and am looking into much faster approaches if available.
This is how I currently loading the image into the image box. (Which is slow too - few seconds to load)
resizedImage = new System.Drawing.Bitmap(OriginalImage, new System.Drawing.Size((int)(OriginalImage.Width * zoomFactor), (int)(OriginalImage.Height * zoomFactor)));
imgBox.Image = resizedImage;
What is the best way to slice this image faster?
This is my current slicing routine .
private void CropSolderJoints()
{
//ordinatesToCrop CordsToCrop = createCordinatesToCrop();
try
{
PB.Maximum = Adjustedcordinates.Pins.Count;
double OriginX = Convert.ToDouble(txtOriginX.Text);
double OriginY = Convert.ToDouble(txtOriginY.Text);
double Scale = Convert.ToDouble(txtScale.Text);
double BumpSize = Convert.ToDouble(txtBumpSize.Text);
Stopwatch watch = new Stopwatch();
watch.Start();
System.Drawing.PointF pos = new System.Drawing.PointF();
double zoomFactor = (float)(double)(Math.Max(imgBox.Width, imgBox.Height) / (double)Math.Max(OriginalImage.Width, OriginalImage.Height));
System.Drawing.Size lensPixelSize = new System.Drawing.Size((int)Math.Round(BumpSize / zoomFactor), (int)Math.Round(BumpSize / zoomFactor));
Rectangle CropJointRectangle = new Rectangle(0, 0, (int)Math.Round(BumpSize / zoomFactor), (int)Math.Round(BumpSize / zoomFactor));
int pinCount = 0;
float radius = (float)(BumpSize) / 2;
foreach (PinCordinates p in Adjustedcordinates.Pins)
{
{
{
PB.Invoke(new MethodInvoker(delegate {
}));
string folderName = new DirectoryInfo(imageFolder).Name;
string filename = dgvImages.SelectedCells[1].Value.ToString();
string Imagefilename = String.Format("{0}_{1}_{2}_{3}", folderName, Path.GetFileNameWithoutExtension(filename), p.defect.ToString(), p.PinLabel);
string saveFilePath = String.Format("{0}\\{1}.{2}", imageFolder, Imagefilename, "png");
float TopLeftX = (float)(OriginX + (float)(p.Cordinates.X * Scale));
float TopLeftY = (float)(OriginY + (float)(p.Cordinates.Y * Scale));
float length = (float)(BumpSize);
float width = (float)(BumpSize);
pos = new System.Drawing.PointF((float)(TopLeftX), (float)(TopLeftY));
imageLens.Location = pkg.GetLensPosition(pos, imageLens);
imageLens.Size = lensUseRelativeSize
? pkg.GetScaledLensSize(imgBox.ClientRectangle, SourceImage.Size, lensPixelSize)
: lensPixelSize;
RectangleF section = pkg.CanvasToImageRect(imgBox.ClientRectangle, SourceImage.Size, imageLens);
Bitmap imgJoint = new Bitmap((int)Math.Round(BumpSize / zoomFactor), (int)Math.Round(BumpSize / zoomFactor));
Graphics g = Graphics.FromImage(imgJoint);
pkg.DrawImageSelection(g, CropJointRectangle, section, SourceImage);
g.DrawImage(imgJoint, 0, 0);
picZoom.Image = imgJoint;
imgJoint.Save(saveFilePath);
PB.Value = pinCount;
pinCount++;
picZoom.Refresh();
}
}
}
PB.Value = 0;
watch.Stop();
label1.Text = watch.Elapsed.TotalSeconds.ToString();
MessageBox.Show("Slicing completed sucessfully." + pinCount.ToString() + "bumps sliced.");
}
catch (Exception ex)
{
MessageBox.Show(ex.Message);
}
}

Creating a Mosaic out of multiple images increases the luminance of the final image

I am trying to create a collage of images with Magick.net. I am using MagickImageCollection and .Mosaic(). I tried already a few of the functions provided by MagickImageCollection but all of them increase the brightness of the final image. The only one that worked so far was .Montage(), but with .Montage() I don't get the padding right.
How do I need to configure it, that .Mosaic() keeps the colors as they are in the single images?
using (var collection = new MagickImageCollection())
{
for (var i = 0; i < thumbnailCount; i++)
{
var image = new MagickImage(TempThumbPathFor(i));
image.Resize(256, 0);
var posX = (image.Page.Width + margin) * (i % 2);
var posY = (image.Page.Height + margin) * (i / 2);
image.Page = new MagickGeometry(posX, posY, new Percentage(100), new Percentage(100));
collection.Add(image);
}
using (var result = collection.Mosaic())
{
result.Write(newPath);
}
}
Collage of images with washed out colors:
For more information why the problem occurred in the first place have a look at this issue: GitHub

Figured out how to create a montage with padding and proper color. Couldn't get it to work with .Mosaic but with .Montage().
The important part is to add the margin to X, Y, Height and Width and call .Trim() on the final image. You will most likely have to play around a bit with the margin to get a balanced looking padding between the images, but other than that it works quite well.
const int margin = 2;
MagickGeometry geometry = null;
using (var collection = new MagickImageCollection())
{
for (var i = 0; i < thumbnailCount; i++)
{
var image = new MagickImage(TempThumbPathFor(i));
image.Resize(256, 0);
collection.Add(image);
if (i == 0)
{
geometry = image.BoundingBox;
geometry.X += margin;
geometry.Width += margin;
geometry.Y += margin;
geometry.Height += margin - 1;
}
}
using (var result = collection.Montage(new MontageSettings()
{
Geometry = geometry,
BackgroundColor = MagickColor.FromRgb(255, 255, 255)
}))
{
result.Trim();
result.Write(newPath);
}
}

Usage of a Picture instead of Rectangle Shape in C#

Background: I am currently busy with showing position of a Vehicle on a Zoomable Canvas based on the Position (X,Y) and Orientation (for Rotation). I use Rectangle for visualizing the vehicle. Everything works well but I got a bit greedy and now I want to replace the Rectangle with Top View Picture of the Vehicle, so it looks that the vehicle itself is moving instead a Rectangle.
Code Below:
private void PaintLocationVehicle(VehicleClass vc)
{
IEnumerable<Rectangle> collection = vc.ZoomableCanvas.Children.OfType<Rectangle>().Where(x => x.Name == _vehicleobjectname);
List<Rectangle> listE = collection.ToList<Rectangle>();
for (int e = 0; e < listE.Count; e++)
vc.ZoomableCanvas.Children.Remove(listE[e]);
// Assign X and Y Position from Vehicle
double drawingX = vc.gCurrentX * GlobalVar.DrawingQ;
double drawingY = vc.gCurrentY * GlobalVar.DrawingQ;
// Scale Length and Width of Vehicle
double tractorWidthScaled = vc.tractorWidth * GlobalVar.DrawingQ;
double tractorLengthScaled = vc.tractorLength * GlobalVar.DrawingQ;
// Get Drawing Location
double _locationX = drawingX - (tractorLengthScaled / 2);
double _locationY = drawingY - ((tractorWidthScaled / 2));
RotateTransform rotation = new RotateTransform();
// Angle in 10th of a Degree
rotation.Angle = vc.gCurrentTheeta/10 ;
double i = 0;
//paint the node
Rectangle _rectangle = new Rectangle();
_rectangle.Stroke = new SolidColorBrush((Color)ColorConverter.ConvertFromString(vc.VehicleColor == "" ? "Black" : vc.VehicleColor));
_rectangle.Fill = new SolidColorBrush((Color)ColorConverter.ConvertFromString(vc.VehicleColor == "" ? "Black" : vc.VehicleColor));
i += 0;
_rectangle.Width = tractorLengthScaled ;
_rectangle.Height = tractorWidthScaled;
rotation.CenterX = _rectangle.Width / 2;
rotation.CenterY = _rectangle.Height / 2;
_rectangle.RenderTransform = rotation;
Canvas.SetTop(_rectangle, _locationY + i);
Canvas.SetLeft(_rectangle, _locationX + i);
_rectangle.SetValue(ZoomableCanvas.ZIndexProperty, 2);
string _tooltipmsg = "Canvas: " + vc.ZoomableCanvas.Name;
// Assign ToolTip Values for User
_tooltipmsg += "\nX: " + vc.gCurrentX;
_tooltipmsg += "\nY: " + vc.gCurrentY;
_rectangle.ToolTip = _tooltipmsg;
_rectangle.Name = _vehicleobjectname;
//add to the canvas
vc.ZoomableCanvas.Children.Add(_rectangle);
}
Note: VehicleClass holds all the Values for a certain Vehicle. DrawingQ holds the transformation scale from Reality to Zoomable Canvas.
So the issues I forsee:
How to append the Size of a Jpeg file to get the size same as
Rectangle?
What kind of Shape object shall I use? Please
suggest.

If i undrestand you correctly. you wanted to show an image of the vechicle inside the rectangle. in order to do that you can use
ImageBrush and assign to the Rectangle Fill property
something like this
Rectangle rect = new Rectangle();
rect.Width = 100;
rect.Height = 100;
ImageBrush img = new ImageBrush();
BitmapImage bmp = new BitmapImage();
bmp.BeginInit();
bmp.UriSource = new Uri("vehicle image path");
bmp.EndInit();
img.ImageSource = bmp;
rect.Fill = img;
I hope that helps

Dynamically creating charts

I am trying to dynamically create a chart for each drive in the computer, inside a form.
Each chart should be a pie chart that contains the amount of free space (colored green) and used space(colored red) in GBs.
But when I run the following code the only thing I see is blank rectangles with the titles of "C:\", "D:\" and so on.
Here is the code :
public static void DrawCharts()
{
Chart[] charts = new Chart[DriveInfo.GetDrives().Length];
DriveInfo[] drives = DriveInfo.GetDrives();
for (int i = 0; i < drives.Length; i++)
{
charts[i] = new Chart();
charts[i].Palette = ChartColorPalette.BrightPastel;
charts[i].Titles.Add(drives[i].Name);
charts[i].Series.Add("Storage");
charts[i].Series[0].ChartType = SeriesChartType.Pie;
charts[i].Location = new System.Drawing.Point(20 + i * 231, 30);
charts[i].Size = new System.Drawing.Size(230, 300);
DataPoint d = new DataPoint();
d.XValue = 1;
double[] p = { (double)drives[i].TotalFreeSpace / 1000000000 };
d.YValues = p;
d.Color = System.Drawing.Color.YellowGreen;
d.Label = "Free Space";
charts[i].Series[0].Points.Add(d);
d.Label = "Used Space";
d.XValue = 2;
double[] a = { (double)((drives[i].TotalSize - drives[i].TotalFreeSpace) / 1000000000) };
d.YValues = a;
d.Color = System.Drawing.Color.Red;
charts[i].Series[0].Points.Add(d);
Form1.tabs.TabPages[1].Controls.Add(charts[i]);
charts[i].Invalidate();
}
}
Thanks.

You are almost there.
But the most basic thing you need to add to a dynamically created chart..:
charts[i] = new Chart();
..is a ChartArea:
charts[i].ChartAreas.Add("CA1"); // pick your name!
Without it no Series can display..
Use it to style the axis with TickMarks, GridLines or Labels or to set Minima and Maxima and Intervals. Well, at least for most other ChartTypes; Pies don't need any of this anyway..
Note that you can have several ChartAreas in one Chart.
Also note that it still will display nothing until at least one Series has at least one DataPoint..

WPF Modify Path Data at Runtime

Hi I have a path from GetFlattenedPathGeometry where i can iterate through the figures and segments to get the points to add to a PointCollection.
I then multiply each point.x/y by a scale factor to get a full scaled version of the original path data. (not using scaletransform as it doesn't suit my requirements).
If i use something like:
public static PathGeometry GetPathGeometry(PointCollection polygonCorners)
{
List<PathSegment> pathSegments = new List<PathSegment> { new PolyLineSegment(polygonCorners, true) };
PathGeometry pathGeometry = new PathGeometry();
pathGeometry.Figures.Add(new PathFigure(polygonCorners[0], pathSegments, true));
return pathGeometry;
}
It returns a new path geometry but doesn't handle ellipses with excluded path geometry in that the path is just one continuous line.
Is there a way to convert the PointCollection to Path.Data (eg: with the "M" "L" and such) for me to re-use Geometry.Parse(the new string)?
Here is the code i'm using to get the flattenedgeometry pointcollection:
PathGeometry g = path.Data.GetFlattenedPathGeometry();
foreach (var f in g.Figures)
{
foreach (var s in f.Segments)
{
if (s is PolyLineSegment)
{
foreach (var pt in ((PolyLineSegment) s).Points)
{
strGeom += pt.ToString();
Point ptn = new Point(pt.X * ScaleX, pt.Y * ScaleY);
pcol.Add(ptn);
}
}
}
}
< Edit Images >
Here is the original path with rectangles and ellipses subtracted from the geometry.
And here is what is looks like re-creating from the code.
If i use the original GetFlattenedPathGeometry, it looks like the original but i need to scale the points to a new resolution.
Hope this makes it clearer.

You could simply call ToString on the PathGeometry to get the whole path data string at once:
var sourceGeometry = path.Data.GetFlattenedPathGeometry();
var geometryString = sourceGeometry.ToString(CultureInfo.InvariantCulture);
var targetGeometry = Geometry.Parse(geometryString);
And why can't you just apply a ScaleTransform to the whole geometry before calling GetFlattenedPathGeometry? The following works perfectly for me (with two EllipseGeometries in an excluding CombinedGeometry):
var pathGeometry = path.Data.Clone();
pathGeometry.Transform = new ScaleTransform(0.5, 0.5);
var scaledGeometry = pathGeometry.GetFlattenedPathGeometry();
EDIT: From what you write in your question and comments, I'm guessing that all you actually want to do is to add or combine geometries with different scaling factors. If that is true, your flattened geometry approach is by far to complicated, as you could easily do that with the following two methods:
private PathGeometry AddGeometries(
Geometry geometry1, Geometry geometry2, double scale)
{
geometry2 = geometry2.Clone();
geometry2.Transform = new ScaleTransform(scale, scale);
var pathGeometry = PathGeometry.CreateFromGeometry(geometry1);
pathGeometry.AddGeometry(geometry2);
return pathGeometry;
}
private PathGeometry CombineGeometries(
Geometry geometry1, Geometry geometry2, GeometryCombineMode mode, double scale)
{
geometry2 = geometry2.Clone();
geometry2.Transform = new ScaleTransform(scale, scale);
return Geometry.Combine(geometry1, geometry2, mode, null);
}
Given a Path with some geometry in its Data property, you may now add (or combine) an arbitray other geometry with a scaling factor with a call like this:
Geometry newGeometry1 = ...
double scale1 = ...
path.Data = AddGeometries(path.Data, newGeometry1, scale1);
Geometry newGeometry2 = ...
double scale2 = ...
path.Data = CombineGeometries(path.Data, newGeometry2,
GeometryCombineMode.Exclude, scale2);

Found the answer by perseverance.
The code to get each point of flattenedpathgeometry and add a scale to each point and recreate the same flattenedpathgeometry with the new points. hope it helps someone. And thanks Clemens. Appreciate your efforts.
path.Data = Geometry.Parse(CurrentObject.Geometry1);
PathGeometry g = path.Data.GetFlattenedPathGeometry();
PathGeometry g = path.Data.GetFlattenedPathGeometry();
foreach (var f in g.Figures)
{
Point pt1 = f.StartPoint;
pt1.X = pt1.X * ScaleX;
pt1.Y = pt1.Y * ScaleY;
strGeom += "M" + pt1.ToString();
foreach (var s in f.Segments)
if (s is PolyLineSegment)
{
count = 0;
foreach (var pt in ((PolyLineSegment)s).Points)
{
int scount = ((PolyLineSegment)s).Points.Count;
if (count == 0)
{
Point pts = new Point(pt.X * ScaleX, pt.Y * ScaleY);
strGeom += "L" + pts.ToString();
}
else if (count < scount)
{
Point pts = new Point(pt.X * ScaleX, pt.Y * ScaleY);
strGeom += " " + pts.ToString();
}
else if (count == scount)
{
Point pts = new Point(pt.X * ScaleX, pt.Y * ScaleY);
strGeom += " " + pts.ToString() + "Z";
}
count++;
}
}
}
path.Data = Geometry.Parse(strGeom);
Here's an image of the paths sent from a remote session: 1366x768 scales to 1920x1080