Performs backward quadrilateral transformation into an area in destination image.
The class implements backward quadrilateral transformation algorithm, which allows to transform any rectangular image into any quadrilateral area in a given destination image. The idea of the algorithm is based on homogeneous transformation and its math is described by Paul Heckbert in his "Projective Mappings for Image Warping" paper.
The image processing routines implements similar math to QuadrilateralTransformation, but performs it in backward direction.
The image processing filter accepts 8 grayscale images and 24/32 bpp color images for processing.
Sample usage:
// define quadrilateral's corners List<IntPoint> corners = new List<IntPoint>( ); corners.Add( new IntPoint( 99, 99 ) ); corners.Add( new IntPoint( 156, 79 ) ); corners.Add( new IntPoint( 184, 126 ) ); corners.Add( new IntPoint( 122, 150 ) ); // create filter BackwardQuadrilateralTransformation filter = new BackwardQuadrilateralTransformation( sourceImage, corners ); // apply the filter Bitmap newImage = filter.Apply( image ); Source image:
Destination image:
Result image:
private Bitmap cutLot(Bitmap blackCanvas, System.Drawing.Point[] ParkingPoint, int i)
{
Bitmap compoundImage = null;
System.Drawing.Point[] parkingLot = { ParkingPoint[0 + (4 * i)], ParkingPoint[1 + (4 * i)],
ParkingPoint[2 + (4 * i)], ParkingPoint[3 + (4 * i)] };
List<AForge.IntPoint> corners = new List<AForge.IntPoint>();
corners.Add(new AForge.IntPoint(ParkingPoint[3 + (4 * i)].X, ParkingPoint[3 + (4 * i)].Y));
corners.Add(new AForge.IntPoint(ParkingPoint[0 + (4 * i)].X, ParkingPoint[0 + (4 * i)].Y));
corners.Add(new AForge.IntPoint(ParkingPoint[1 + (4 * i)].X, ParkingPoint[1 + (4 * i)].Y));
corners.Add(new AForge.IntPoint(ParkingPoint[2 + (4 * i)].X, ParkingPoint[2 + (4 * i)].Y));
QuadrilateralTransformation Qfilter = new QuadrilateralTransformation(corners, 200, 200);
//Bitmap frame = new Bitmap(@"currImage.jpg");
Bitmap frame = (Bitmap)currentFrame.Clone();
Bitmap nframe = Qfilter.Apply(frame);
nframe.RotateFlip(RotateFlipType.Rotate180FlipY);
BackwardQuadrilateralTransformation BQfilter = new BackwardQuadrilateralTransformation(nframe, corners);
compoundImage = BQfilter.Apply(blackCanvas);
return nframe;
}
public void picback()
{
Bitmap temp1;
Bitmap temp2;
Bitmap temp3;
Bitmap temp4;
Bitmap temp5;
Bitmap temp6;
Bitmap temp7;
Bitmap temp8;
Bitmap temp9;
Bitmap temp10;
Bitmap sourceImage;
//新建轮廓过滤器
CannyEdgeDetector filter = new CannyEdgeDetector();
//生成颜色过滤器
ColorFiltering colorFilter = new ColorFiltering();
//将颜色过滤器设置为白色
colorFilter.Red = new IntRange(50, 255);
colorFilter.Green = new IntRange(50, 255);
colorFilter.Blue = new IntRange(50, 255);
//从摄像头中截取图像
sourceImage = videoSourcePlayer1.GetCurrentVideoFrame();
//将原图格式化复制
temp1 = AForge.Imaging.Image.Clone(sourceImage, sourceImage.PixelFormat);
//清除sourceImage占用
sourceImage.Dispose();
//sourceImage = temp1;
int Height = temp1.Size.Height;
int Width = temp1.Size.Width;
//pictureBox1是原图
//pictureBox1.Image = temp1;
//从temp1提取颜色
temp2 = filter.Apply(temp1.PixelFormat != PixelFormat.Format8bppIndexed ?
Grayscale.CommonAlgorithms.BT709.Apply(temp1) : temp1);
//pictureBox2原图轮廓
//pictureBox2.Image = temp2;
//从temp1进行颜色过滤
temp5 = colorFilter.Apply(temp1);
//pictureBox5原图轮廓
//pictureBox5.Image = temp5;
//从temp5进行灰度转化
temp3 = new Grayscale(0.2125, 0.7154, 0.0721).Apply(temp5);
//pictureBox3灰度转化
//pictureBox3.Image = temp3;
//从temp3进行二值化
temp4 = new Threshold(10).Apply(temp3);
//pictureBox4是二值化后的图
//pictureBox4.Image = temp4;
//temp7去噪点后的图
temp7 = new BlobsFiltering(40, 40, temp4.Width, temp4.Height).Apply(temp4);
//pictureBox7.Image = temp7;
//temp6先原图格式化复制
temp6 = AForge.Imaging.Image.Clone(temp7, temp1.PixelFormat);
temp8 = temp6;
try
{
QuadrilateralFinder qf = new QuadrilateralFinder();//获取三角形、四边形角点
List <IntPoint> corners = qf.ProcessImage(temp6);
//进行角点转换
corners = CornersChange(corners, temp6.Size.Width, temp6.Size.Height);
//生成四角变换过滤器
QuadrilateralTransformation filter2 = new QuadrilateralTransformation(corners, 1920, 1040);
//对原图temp1进行四角型变换
temp8 = filter2.Apply(temp1);
}
catch
{
}
//temp9为temp8的复制
temp9 = AForge.Imaging.Image.Clone(temp8, temp1.PixelFormat);
//pictureBox8.Image = temp8;
//生成一个新的过滤器
ColorFiltering colorFilter2 = new ColorFiltering();
colorFilter2.Red = new IntRange(100, 255);
colorFilter2.Green = new IntRange(100, 255);
colorFilter2.Blue = new IntRange(0, 90);
//提取颜色
temp5 = colorFilter2.Apply(temp9);
//灰度转化
temp3 = new Grayscale(0.2125, 0.7154, 0.0721).Apply(temp5);
//二值化
temp4 = new Threshold(10).Apply(temp3);
//去噪点
temp7 = new BlobsFiltering(40, 40, temp4.Width, temp4.Height).Apply(temp4);
temp6 = AForge.Imaging.Image.Clone(temp7, temp9.PixelFormat);
temp10 = AForge.Imaging.Image.Clone(temp6, temp6.PixelFormat);
pictureBox8.Image = temp10;
try
{
QuadrilateralFinder qf = new QuadrilateralFinder();//获取三角形、四边形角点
List <IntPoint> corners = qf.ProcessImage(temp6);
corners = CornersChange(corners, temp6.Size.Width, temp6.Size.Height);
Rectangle rect = new Rectangle();
rect = Screen.GetWorkingArea(this);
string path = OriPath + "\\SourceInputImage.jpg";
Bitmap bt = new Bitmap(path);
//初始化一个和屏幕面积一样大小的bitmap且格式和bt一样
DisplayBitmap = new Bitmap(rect.Width, rect.Height, bt.PixelFormat);
Graphics g = Graphics.FromImage(DisplayBitmap);
g.FillRectangle(Brushes.White, new Rectangle(0, 0, rect.Width, rect.Height));//这句实现填充矩形的功能
AForge.Imaging.Filters.BackwardQuadrilateralTransformation Bfilter = new AForge.Imaging.Filters.BackwardQuadrilateralTransformation(bt, corners);
temp10 = Bfilter.Apply(DisplayBitmap);
//string testsavepath = OriPath + "\\SourcePic.bmp";
//DisplayBitmap.Save(testsavepath);
/*
* BitmapData data = temp6.LockBits(new Rectangle(0, 0, temp6.Width, temp6.Height),
* ImageLockMode.ReadWrite, temp6.PixelFormat);
* Drawing.Polygon(data, corners, Color.Red);
* for (int i = 0; i < corners.Count; i++)
* {
* Drawing.FillRectangle(data,
* new Rectangle(corners[i].X - 2, corners[i].Y - 2, 10, 10),
* Color.Red);
* }
*
* temp6.UnlockBits(data);
*/
}
catch
{
}
pictureBox9.Image = temp10;
}
