Move canvas to the specified point.
The filter moves canvas to the specified area filling unused empty areas with specified color.
The filter accepts 8/16 bpp grayscale images and 24/32/48/64 bpp color image for processing.
Sample usage:
// create filter CanvasMove filter = new CanvasMove( new IntPoint( -50, -50 ), Color.Green ); // apply the filter filter.ApplyInPlace( image ); Initial image:
Result image:
public void DeSkew()
{
Rectangle vBoundary = new Rectangle(new Point(0, 0), new Size(140, originalImage.Height));
Emgu.CV.Cvb.CvBlobDetector bDetect = new Emgu.CV.Cvb.CvBlobDetector();
Emgu.CV.Cvb.CvBlobs markerBlob = new Emgu.CV.Cvb.CvBlobs();
List<Rectangle> blobs = new List<Rectangle>();
Image<Gray, Byte> preprocessImage = originalImage.Convert<Gray, Byte>();
preprocessImage = preprocessImage.ThresholdBinary(new Gray(200), new Gray(255));
preprocessImage = preprocessImage.Not();
markerBlob.Clear();
bDetect.Detect(preprocessImage, markerBlob);
preprocessImage.Dispose();
preprocessImage = null;
markerBlob.FilterByArea(250, 1800);
foreach (Emgu.CV.Cvb.CvBlob targetBlob in markerBlob.Values)
{
if (vBoundary.Contains(targetBlob.BoundingBox))
{
if (targetBlob.BoundingBox.Width >= targetBlob.BoundingBox.Height - 5)
{
Rectangle r = new Rectangle(targetBlob.BoundingBox.X, targetBlob.BoundingBox.Y, targetBlob.BoundingBox.Width, targetBlob.BoundingBox.Height);
blobs.Add(r);
}
}
}
RectangleF temp = blobs.First();
RectangleF temp2 = blobs.Last();
double dY = Math.Abs(temp.Y - temp2.Y);
double dX = Math.Abs(temp.X - temp2.X);
double angle = Math.Atan2(dX, dY);
angle = angle * (180 / Math.PI);
if (temp2.X > temp.X)
{
angle = angle * -1;
}
RotatedRect rot_rec = new RotatedRect();
rot_rec.Center = new PointF(temp.X, temp.Y);
RotationMatrix2D rot_mat = new RotationMatrix2D(rot_rec.Center, angle, 1);
Image<Bgr, Byte> outimage = originalImage.CopyBlank();
CvInvoke.WarpAffine(originalImage, outimage, rot_mat, originalImage.Size, Inter.Cubic, Warp.Default, BorderType.Constant, new Bgr(Color.White).MCvScalar);
int xOffset = 80 - (int)temp.X;
int yOffset = 45 - (int)temp.Y;
originalImage = outimage.Copy();
Bitmap a = originalImage.ToBitmap();
CanvasMove filter = new CanvasMove(new AForge.IntPoint(xOffset, yOffset), Color.White);
a = filter.Apply(a);
originalImage = new Image<Bgr, Byte>(a);
a.Dispose();
a = null;
outimage.Dispose();
outimage = null;
blobs = null;
}
