C# crop circle in a image or bitmap
I am sure its easy but can't seem to find anyone that has the answer. I have an image and I need to cut a circle or even other shapes out of that image. I need this code to be in .net c#. I am doing this in a class so its not wpf or a winform. I will need to pass x and y pos and the size of the circle.
Other option is AForge, ImageStatistics. I need to get a circle (part of the image) and get StdDev.
Thanks for the help. Andrew
-- update to chris post.
Here is chris post in c#. Not as clean as his but its a start.
public System.Drawing.Image x(string sourceFile, int circleUpperLeftX, int circleUpperLeftY, int circleDiameter)
{
Bitmap SourceImage = new Bitmap(System.Drawing.Image.FromFile(sourceFile));
Rectangle CropRect = new Rectangle(circleUpperLeftX, circleUpperLeftY, circleDiameter, circleDiameter);
Bitm开发者_开发百科ap CroppedImage = SourceImage.Clone(CropRect, SourceImage.PixelFormat);
TextureBrush TB = new TextureBrush(CroppedImage);
Bitmap FinalImage = new Bitmap(circleDiameter, circleDiameter);
Graphics G = Graphics.FromImage(FinalImage);
G.FillEllipse(TB, 0, 0, circleDiameter, circleDiameter);
return FinalImage;
}
You can use a TextureBrush. The code below crops the image to a square, then loads that into a texture brush and finally draws an ellipse/circle using that brush:
Private Shared Function CropImageToCircle(ByVal sourceFile As String, ByVal circleUpperLeftX As Integer, ByVal circleUpperLeftY As Integer, ByVal circleDiameter As Integer) As Image
''//Load our source image
Using SourceImage As New Bitmap(Image.FromFile(sourceFile))
''//Create a rectangle that crops a square of our image
Dim CropRect As New Rectangle(circleUpperLeftX, circleUpperLeftY, circleDiameter, circleDiameter)
''//Crop the image to that square
Using CroppedImage = SourceImage.Clone(CropRect, SourceImage.PixelFormat)
''//Create a texturebrush to draw our circle with
Using TB As New TextureBrush(CroppedImage)
''//Create our output image
Dim FinalImage As New Bitmap(circleDiameter, circleDiameter)
''//Create a graphics object to draw with
Using G = Graphics.FromImage(FinalImage)
''//Draw our cropped image onto the output image as an ellipse with the same width/height (circle)
G.FillEllipse(TB, 0, 0, circleDiameter, circleDiameter)
Return FinalImage
End Using
End Using
End Using
End Using
End Function
Make a new Bitmap that matches the original in size and pixel format. Create a graphics from that new Bitmap. Set the graphics clip to a new circle. Draw the original image onto the new graphics.
public Bitmap ClipToCircle(Bitmap original, PointF center, float radius)
{
Bitmap copy = new Bitmap(original);
using (Graphics g = Graphics.FromImage(copy)) {
RectangleF r = new RectangleF(center.X - radius, center.Y - radius, radius * 2, radius * 2);
GraphicsPath path = new GraphicsPath();
path.AddEllipse(r);
g.Clip = new Region(path);
g.DrawImage(original, 0, 0);
return copy;
}
}
this code may help you Screenshot
Class Code:
using System;
using System.Drawing;
using System.Drawing.Drawing2D;
using System.Drawing.Imaging;
public class ImageHelper
{
public Image CropImage(Image img)
{
int x = img.Width/2;
int y = img.Height/2;
int r = Math.Min(x, y);
Bitmap tmp = null;
tmp = new Bitmap(2 * r, 2 * r);
using (Graphics g = Graphics.FromImage(tmp))
{
g.SmoothingMode = SmoothingMode.AntiAlias;
g.TranslateTransform(tmp.Width / 2, tmp.Height / 2);
GraphicsPath gp = new GraphicsPath();
gp.AddEllipse(0 - r, 0 - r, 2 * r, 2 * r);
Region rg = new Region(gp);
g.SetClip(rg, CombineMode.Replace);
Bitmap bmp = new Bitmap(img);
g.DrawImage(bmp, new Rectangle(-r, -r, 2 * r, 2 * r), new Rectangle(x - r, y - r, 2 * r, 2 * r), GraphicsUnit.Pixel);
}
return tmp;
}
public void SaveImage(Image img,string path,ImageFormat imageFormat)
{
img.Save(path, imageFormat);
}
}
Form1.cs
using System;
using System.Drawing;
using System.Drawing.Imaging;
using System.Windows.Forms;
namespace CropImageToCircle
{
//Browse Image
private void button1_Click(object sender, EventArgs e)
{
var ofd = new OpenFileDialog();
ofd.Filter = "Choose Image(*.jpg;,*.jpeg;,*.png;)|*.jpg;,*.jpeg;,*.png;";
if(ofd.ShowDialog()== DialogResult.OK)
{
pictureBox1.Image =Image.FromFile( ofd.FileName);
}
}
//CropToCircle
private void button2_Click(object sender, EventArgs e)
{
var imageHelper = new ImageHelper();
pictureBox2.Image= imageHelper.CropImage(pictureBox1.Image);
}
//Save Image
private void button3_Click(object sender, EventArgs e)
{
var imageHelper = new ImageHelper();
var sfd = new SaveFileDialog();
sfd.FileName = "*";
sfd.DefaultExt = "png";
sfd.Filter = "Png Image (.png)|*.png ";
sfd.ValidateNames = true;
sfd.FilterIndex = 1;
if (sfd.ShowDialog() == DialogResult.OK)
{
imageHelper.SaveImage(pictureBox2.Image,sfd.FileName,ImageFormat.Png);
}
}
}
}
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