C＃在图像或位图中裁剪圆圈

我确信它很容易，但似乎找不到任何有答案的人。 我有一个图像，我需要从该图像中切出一个圆或甚至其他形状。 我需要这个代码在.net c＃中。 我在课堂上这样做，所以它不是wpf或winform。 我需要传递x和y pos以及圆的大小。

其他选择是AForge，ImageStatistics。 我需要得到一个圆圈（图像的一部分）并获得StdDev。

谢谢您的帮助。 安德鲁

– 更新到chrispost。

这是c＃中的chrispost。 不像他那么干净，但却是一个开始。

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); Bitmap 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; } 

Answer 1

您可以使用TextureBrush 。 下面的代码将图像裁剪为正方形，然后将其加载到纹理画笔中，最后使用该画笔绘制椭圆/圆形：

 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 

Answer 2

创建一个与原始大小和像素格式匹配的新Bitmap。 从新的位图创建图形。 将图形剪辑设置为新圆圈。 将原始图像绘制到新图形上。

 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; } } 

Answer 3

看到这个 。 您需要调用所需function的GDI +类（在C＃中没有问题）。

Answer 4

这段代码可能会帮助你截图

class级代码：

 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的

 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); } } } 

}