/// <summary>
/// Draws text on the provided image.
/// </summary>
/// <param name="image">Input image.</param>
/// <param name="text">User text.</param>
/// <param name="font">Font.</param>
/// <param name="botomLeftPoint">Bottom-left point.</param>
/// <param name="color">Text color.</param>
/// <param name="opacity">Sets alpha channel where 0 is transparent and 255 is full opaque.</param>
public unsafe static void Draw(this Bgr <byte>[,] image, string text, Font font, Point botomLeftPoint, Bgr <byte> color, byte opacity = Byte.MaxValue)
{
using (var img = image.Lock())
{
var iplImage = img.AsOpenCvImage();
CvCoreInvoke.cvPutText(&iplImage, text, botomLeftPoint, ref font, color.ToCvScalar());
}
}
/// <summary>
/// Draws ellipse.
/// </summary>
/// <param name="image">Input image.</param>
/// <param name="ellipse">Ellipse.</param>
/// <param name="color">Object's color.</param>
/// <param name="thickness">Border thickness.</param>
public unsafe static void Draw(this Bgr <byte>[,] image, Ellipse ellipse, Bgr <byte> color, int thickness)
{
using (var img = image.Lock())
{
var iplImage = img.AsOpenCvImage();
CvCoreInvoke.cvEllipse(&iplImage, ellipse.Center.Round(), Size.Round(ellipse.Size), ellipse.Angle,
0, 2 * System.Math.PI, color.ToCvScalar(), thickness, LineTypes.EightConnected, 0);
}
}
/// <summary>
/// Converts an image to an bitmap.
/// </summary>
/// <param name="img">Input image.</param>
/// <returns>Bitmap</returns>
public static Bitmap ToBitmap(this Bgr <short>[,] img)
{
Bitmap bmp = null;
using (var uImg = img.Lock())
{
bmp = toBitmap(uImg, PixelFormat.Format48bppRgb);
}
return(bmp);
}
/// <summary>
/// Draws circle.
/// </summary>
/// <param name="image">Input image.</param>
/// <param name="circle">Circle</param>
/// <param name="color">Circle color.</param>
/// <param name="thickness">Contours thickness.</param>
public unsafe static void Draw(this Bgr <byte>[,] image, Circle circle, Bgr <byte> color, int thickness)
{
using (var img = image.Lock())
{
var iplImage = img.AsOpenCvImage();
var center = new Point(circle.X, circle.Y);
CvCoreInvoke.cvCircle(&iplImage, center, circle.Radius, color.ToCvScalar(),
thickness, LineTypes.EightConnected, 0);
}
}
/// <summary>
/// Draws rectangle.
/// </summary>
/// <param name="image">Input image.</param>
/// <param name="rect">Rectangle.</param>
/// <param name="color">Object's color.</param>
/// <param name="thickness">Border thickness. If less than zero structure will be filled.</param>
/// <param name="opacity">Sets alpha channel where 0 is transparent and 255 is full opaque.</param>
public unsafe static void Draw(this Bgr <byte>[,] image, Rectangle rect, Bgr <byte> color, int thickness, byte opacity = Byte.MaxValue)
{
if (float.IsNaN(rect.X) || float.IsNaN(rect.Y))
{
return;
}
using (var img = image.Lock())
{
var iplImage = img.AsOpenCvImage();
CvCoreInvoke.cvRectangleR(&iplImage, rect, color.ToCvScalar(opacity), thickness, LineTypes.EightConnected, 0);
}
}
/// <summary>
/// Draws contour.
/// </summary>
/// <param name="image">Input image.</param>
/// <param name="contour">Contour points.</param>
/// <param name="color">Contour color.</param>
/// <param name="thickness">Contours thickness.</param>
/// <param name="opacity">Sets alpha channel where 0 is transparent and 255 is full opaque.</param>
public unsafe static void Draw(this Bgr <byte>[,] image, Point[] contour, Bgr <byte> color, int thickness, byte opacity = Byte.MaxValue)
{
var contourHandle = GCHandle.Alloc(contour, GCHandleType.Pinned);
using (var img = image.Lock())
{
var iplImage = img.AsOpenCvImage();
//TODO - noncritical: implement with cvContour
CvCoreInvoke.cvPolyLine(&iplImage, new IntPtr[] { contourHandle.AddrOfPinnedObject() }, new int[] { contour.Length }, 1,
true, color.ToCvScalar(), thickness, LineTypes.EightConnected, 0);
}
contourHandle.Free();
}
/// <summary>
/// The blending filter is able to blend two images using a homography matrix.
/// A linear alpha gradient is used to smooth out differences between the two
/// images, effectively blending them in two images. The gradient is computed
/// considering the distance between the centers of the two images.
/// </summary>
/// <param name="im">Image.</param>
/// <param name="overlayIm">The overlay image (also called the anchor).</param>
/// <param name="homography">Homography matrix used to map a image passed to
/// the filter to the overlay image specified at filter creation.</param>
/// <param name="fillColor">The filling color used to fill blank spaces. The filling color will only be visible after the image is converted
/// to 24bpp. The alpha channel will be used internally by the filter.</param>
/// <param name="gradient">A value indicating whether to blend using a linear
/// gradient or just superimpose the two images with equal weights.</param>
/// <param name="alphaOnly">A value indicating whether only the alpha channel
/// should be blended. This can be used together with a transparency
/// mask to selectively blend only portions of the image.</param>
/// <returns>Blended image.</returns>
public static Bgra <byte>[,] Blend(this Bgr <byte>[,] im, Bgr <byte>[,] overlayIm, MatrixH homography, Bgra <byte> fillColor, bool gradient = true, bool alphaOnly = false)
{
Bgra <byte>[,] resultImage = null;
using (var uOverlayIm = overlayIm.Lock())
{
Blend blend = new Blend(homography, uOverlayIm.AsBitmap());
blend.AlphaOnly = alphaOnly;
blend.Gradient = gradient;
blend.FillColor = fillColor.ToColor();
resultImage = im.ApplyBaseTransformationFilter <Bgr <byte>, Bgra <byte> >(blend);
}
return(resultImage);
}
/// <summary>
/// Computes gradient orientations from the color image. Orientation from the channel which has the maximum gradient magnitude is taken as the orientation for a location.
/// </summary>
/// <param name="frame">Image.</param>
/// <param name="magnitudeSqrImage">Squared magnitude image.</param>
/// <param name="minValidMagnitude">Minimal valid magnitude.</param>
/// <returns>Orientation image (angles are in degrees).</returns>
public static unsafe Gray<int>[,] Compute(Bgr<byte>[,] frame, out Gray<int>[,] magnitudeSqrImage, int minValidMagnitude)
{
var minSqrMagnitude = minValidMagnitude * minValidMagnitude;
var orientationImage = new Gray<int>[frame.Height(), frame.Width()];
var _magnitudeSqrImage = orientationImage.CopyBlank();
using (var uFrame = frame.Lock())
{
ParallelLauncher.Launch(thread =>
{
computeColor(thread, (byte*)uFrame.ImageData, uFrame.Stride, orientationImage, _magnitudeSqrImage, minSqrMagnitude);
},
frame.Width() - 2 * kernelRadius, frame.Height() - 2 * kernelRadius);
}
magnitudeSqrImage = _magnitudeSqrImage;
return orientationImage;
}
/// <summary>
/// Draws Box2D.
/// </summary>
/// <param name="image">Input image.</param>
/// <param name="box">Box 2D.</param>
/// <param name="color">Object's color.</param>
/// <param name="thickness">Border thickness.</param>
/// <param name="opacity">Sets alpha channel where 0 is transparent and 255 is full opaque.</param>
public unsafe static void Draw(this Bgr <byte>[,] image, Box2D box, Bgr <byte> color, int thickness, byte opacity = Byte.MaxValue)
{
if (thickness < 1)
{
throw new NotSupportedException("Only positive values are valid!");
}
var vertices = box.GetVertices();
using (var img = image.Lock())
{
var iplImage = img.AsOpenCvImage();
for (int i = 0; i < vertices.Length; i++)
{
int idx2 = (i + 1) % vertices.Length;
CvCoreInvoke.cvLine(&iplImage, vertices[i].Round(), vertices[idx2].Round(),
color.ToCvScalar(opacity), thickness,
LineTypes.EightConnected, 0);
}
}
}
/// <summary>
/// The blending filter is able to blend two images using a homography matrix.
/// A linear alpha gradient is used to smooth out differences between the two
/// images, effectively blending them in two images. The gradient is computed
/// considering the distance between the centers of the two images.
/// </summary>
/// <param name="im">Image.</param>
/// <param name="overlayIm">The overlay image (also called the anchor).</param>
/// <param name="homography">Homography matrix used to map a image passed to
/// the filter to the overlay image specified at filter creation.</param>
/// <param name="fillColor">The filling color used to fill blank spaces. The filling color will only be visible after the image is converted
/// to 24bpp. The alpha channel will be used internally by the filter.</param>
/// <param name="gradient">A value indicating whether to blend using a linear
/// gradient or just superimpose the two images with equal weights.</param>
/// <param name="alphaOnly">A value indicating whether only the alpha channel
/// should be blended. This can be used together with a transparency
/// mask to selectively blend only portions of the image.</param>
/// <returns>Blended image.</returns>
public static Bgra<byte>[,] Blend(this Bgr<byte>[,] im, Bgr<byte>[,] overlayIm, MatrixH homography, Bgra<byte> fillColor, bool gradient = true, bool alphaOnly = false)
{
Bgra<byte>[,] resultImage = null;
using (var uOverlayIm = overlayIm.Lock())
{
Blend blend = new Blend(homography, uOverlayIm.AsBitmap());
blend.AlphaOnly = alphaOnly;
blend.Gradient = gradient;
blend.FillColor = fillColor.ToColor();
resultImage = im.ApplyBaseTransformationFilter<Bgr<byte>, Bgra<byte>>(blend);
}
return resultImage;
}
