private Image <Bgr, byte> Match(Image <Bgr, byte> image1, Image <Bgr, byte> image2, int flag)
{
HomographyMatrix homography = null;
SURFDetector surfDetectorCPU = new SURFDetector(500, false);
int k = 2; //number of matches that we want ot find between image1 and image2
double uniquenessThreshold = 0.8;
Matrix <int> indices;
Matrix <byte> mask;
VectorOfKeyPoint KeyPointsImage1;
VectorOfKeyPoint KeyPointsImage2;
Image <Gray, Byte> Image1G = image1.Convert <Gray, Byte>();
Image <Gray, Byte> Image2G = image2.Convert <Gray, Byte>();
if (GpuInvoke.HasCuda) //Using CUDA, the GPUs can be used for general purpose processing (i.e., not exclusively graphics), speed up performance
{
Console.WriteLine("Here");
GpuSURFDetector surfDetectorGPU = new GpuSURFDetector(surfDetectorCPU.SURFParams, 0.01f);
// extract features from Image1
using (GpuImage <Gray, Byte> gpuImage1 = new GpuImage <Gray, byte>(Image1G)) //convert CPU input image to GPUImage(greyscale)
using (GpuMat <float> gpuKeyPointsImage1 = surfDetectorGPU.DetectKeyPointsRaw(gpuImage1, null)) //find key points for image
using (GpuMat <float> gpuDescriptorsImage1 = surfDetectorGPU.ComputeDescriptorsRaw(gpuImage1, null, gpuKeyPointsImage1)) //calculate descriptor for each key point
using (GpuBruteForceMatcher <float> matcher = new GpuBruteForceMatcher <float>(DistanceType.L2)) //create a new matcher object
{
KeyPointsImage1 = new VectorOfKeyPoint();
surfDetectorGPU.DownloadKeypoints(gpuKeyPointsImage1, KeyPointsImage1); //copy the Matrix from GPU to CPU
// extract features from Image2
using (GpuImage <Gray, Byte> gpuImage2 = new GpuImage <Gray, byte>(Image2G))
using (GpuMat <float> gpuKeyPointsImage2 = surfDetectorGPU.DetectKeyPointsRaw(gpuImage2, null))
using (GpuMat <float> gpuDescriptorsImage2 = surfDetectorGPU.ComputeDescriptorsRaw(gpuImage2, null, gpuKeyPointsImage2))
//for each descriptor of each image2 , we find k best matching points and their distances from image1 descriptors
using (GpuMat <int> gpuMatchIndices = new GpuMat <int>(gpuDescriptorsImage2.Size.Height, k, 1, true)) //stores indices of k best mathces
using (GpuMat <float> gpuMatchDist = new GpuMat <float>(gpuDescriptorsImage2.Size.Height, k, 1, true)) //stores distance of k best matches
using (GpuMat <Byte> gpuMask = new GpuMat <byte>(gpuMatchIndices.Size.Height, 1, 1)) //stores result of comparison
using (Stream stream = new Stream())
{
matcher.KnnMatchSingle(gpuDescriptorsImage2, gpuDescriptorsImage1, gpuMatchIndices, gpuMatchDist, k, null, stream); //matching descriptors of image2 to image1 and storing the k best indices and corresponding distances
indices = new Matrix <int>(gpuMatchIndices.Size);
mask = new Matrix <byte>(gpuMask.Size);
//gpu implementation of voteForUniquess
using (GpuMat <float> col0 = gpuMatchDist.Col(0))
using (GpuMat <float> col1 = gpuMatchDist.Col(1))
{
GpuInvoke.Multiply(col1, new MCvScalar(uniquenessThreshold), col1, stream); //by setting stream, we perform an Async Task
GpuInvoke.Compare(col0, col1, gpuMask, CMP_TYPE.CV_CMP_LE, stream); //col0 >= 0.8col1 , only then is it considered a good match
}
KeyPointsImage2 = new VectorOfKeyPoint();
surfDetectorGPU.DownloadKeypoints(gpuKeyPointsImage2, KeyPointsImage2);
//wait for the stream to complete its tasks
//We can perform some other CPU intesive stuffs here while we are waiting for the stream to complete.
stream.WaitForCompletion();
gpuMask.Download(mask);
gpuMatchIndices.Download(indices);
if (GpuInvoke.CountNonZero(gpuMask) >= 4)
{
int nonZeroCount = Features2DToolbox.VoteForSizeAndOrientation(KeyPointsImage1, KeyPointsImage2, indices, mask, 1.5, 20); //count the number of nonzero points in the mask(this stored the comparison result of col0 >= 0.8col1)
//we can create a homography matrix only if we have atleast 4 matching points
if (nonZeroCount >= 4)
{
homography = Features2DToolbox.GetHomographyMatrixFromMatchedFeatures(KeyPointsImage1, KeyPointsImage2, indices, mask, 2);
}
}
}
}
}
else
{
Console.WriteLine("No CUDA");
//extract features from image2
KeyPointsImage1 = new VectorOfKeyPoint();
Matrix <float> DescriptorsImage1 = surfDetectorCPU.DetectAndCompute(Image1G, null, KeyPointsImage1);
//extract features from image1
KeyPointsImage2 = new VectorOfKeyPoint();
Matrix <float> DescriptorsImage2 = surfDetectorCPU.DetectAndCompute(Image2G, null, KeyPointsImage2);
BruteForceMatcher <float> matcher = new BruteForceMatcher <float>(DistanceType.L2);
matcher.Add(DescriptorsImage1);
indices = new Matrix <int>(DescriptorsImage2.Rows, k);
using (Matrix <float> dist = new Matrix <float>(DescriptorsImage2.Rows, k))
{
matcher.KnnMatch(DescriptorsImage2, indices, dist, k, null);
mask = new Matrix <byte>(dist.Rows, 1);
mask.SetValue(255);
Features2DToolbox.VoteForUniqueness(dist, uniquenessThreshold, mask);
}
int nonZeroCount = CvInvoke.cvCountNonZero(mask);
if (nonZeroCount >= 4)
{
nonZeroCount = Features2DToolbox.VoteForSizeAndOrientation(KeyPointsImage1, KeyPointsImage2, indices, mask, 1.5, 20);
if (nonZeroCount >= 4)
{
homography = Features2DToolbox.GetHomographyMatrixFromMatchedFeatures(KeyPointsImage1, KeyPointsImage2, indices, mask, 2);
}
}
}
Image <Bgr, Byte> mImage = image1.Convert <Bgr, Byte>();
Image <Bgr, Byte> oImage = image2.Convert <Bgr, Byte>();
Image <Bgr, Byte> result = new Image <Bgr, byte>(mImage.Width + oImage.Width, mImage.Height);
//Image<Bgr, Byte> temp = Features2DToolbox.DrawMatches(image1, KeyPointsImage1, image2, KeyPointsImage2, indices, new Bgr(255, 255, 255), new Bgr(255, 255, 255), mask, Features2DToolbox.KeypointDrawType.DEFAULT);
if (homography != null)
{ //draw a rectangle along the projected model
Rectangle rect = image1.ROI;
PointF[] pts = new PointF[] {
new PointF(rect.Left, rect.Bottom),
new PointF(rect.Right, rect.Bottom),
new PointF(rect.Right, rect.Top),
new PointF(rect.Left, rect.Top)
};
homography.ProjectPoints(pts);
HomographyMatrix origin = new HomographyMatrix(); //I perform a copy of the left image with a not real shift operation on the origin
origin.SetIdentity();
origin.Data[0, 2] = 0;
origin.Data[1, 2] = 0;
Image <Bgr, Byte> mosaic = new Image <Bgr, byte>(mImage.Width + oImage.Width, mImage.Height * 2);
Image <Bgr, byte> warp_image = mosaic.Clone();
mosaic = mImage.WarpPerspective(origin, mosaic.Width, mosaic.Height, Emgu.CV.CvEnum.INTER.CV_INTER_LINEAR, Emgu.CV.CvEnum.WARP.CV_WARP_DEFAULT, new Bgr(0, 0, 0));
warp_image = oImage.WarpPerspective(homography, warp_image.Width, warp_image.Height, Emgu.CV.CvEnum.INTER.CV_INTER_LINEAR, Emgu.CV.CvEnum.WARP.CV_WARP_INVERSE_MAP, new Bgr(200, 0, 0));
Image <Gray, byte> warp_image_mask = oImage.Convert <Gray, byte>();
warp_image_mask.SetValue(new Gray(255));
Image <Gray, byte> warp_mosaic_mask = mosaic.Convert <Gray, byte>();
warp_mosaic_mask.SetZero();
warp_mosaic_mask = warp_image_mask.WarpPerspective(homography, warp_mosaic_mask.Width, warp_mosaic_mask.Height, Emgu.CV.CvEnum.INTER.CV_INTER_LINEAR, Emgu.CV.CvEnum.WARP.CV_WARP_INVERSE_MAP, new Gray(0));
warp_image.Copy(mosaic, warp_mosaic_mask);
if (flag == 1)
{
Console.WriteLine("Using Image Blending");
return(blend(mosaic, warp_image, warp_mosaic_mask, 2));
}
else
{
Console.WriteLine("No Image Blending");
return(mosaic);
}
}
return(null);
}
