app第三阶段冲刺第五天

作者：@kuaiquxie
作者的github：https://github.com/bitebita
本文为作者原创，如需转载，请注明出处：https://www.cnblogs.com/dzwj/p/16315912.html

今天写图像特征怎么通过过滤比对实现图像的匹配

import java.io.IOException;
import java.util.ArrayList;
import java.util.List;

import org.opencv.android.Utils;
import org.opencv.calib3d.Calib3d;
import org.opencv.core.Core;
import org.opencv.core.CvType;
import org.opencv.core.DMatch;
import org.opencv.core.KeyPoint;
import org.opencv.core.Mat;
import org.opencv.core.MatOfDMatch;
import org.opencv.core.MatOfKeyPoint;
import org.opencv.core.MatOfPoint;
import org.opencv.core.MatOfPoint2f;
import org.opencv.core.Point;
import org.opencv.core.Scalar;
import org.opencv.features2d.DescriptorExtractor;
import org.opencv.features2d.DescriptorMatcher;
import org.opencv.features2d.FeatureDetector;
import org.opencv.imgcodecs.Imgcodecs;
import org.opencv.imgproc.Imgproc;

import android.content.Context;

import com.nummist.secondsight.filters.Filter;

public final class ImageDetectionFilter implements Filter {

    // The reference image (this detector's target).
    private final Mat mReferenceImage;
    // Features of the reference image.
    private final MatOfKeyPoint mReferenceKeypoints = new MatOfKeyPoint();
    // Descriptors of the reference image's features.
    private final Mat mReferenceDescriptors = new Mat();
    // The corner coordinates of the reference image, in pixels.
    // CvType defines the color depth, number of channels, and
    // channel layout in the image. Here, each point is represented
    // by two 32-bit floats.
    private final Mat mReferenceCorners = new Mat(4, 1, CvType.CV_32FC2);

    // Features of the scene (the current frame).
    private final MatOfKeyPoint mSceneKeypoints = new MatOfKeyPoint();
    // Descriptors of the scene's features.
    private final Mat mSceneDescriptors = new Mat();
    // Tentative corner coordinates detected in the scene, in
    // pixels.
    private final Mat mCandidateSceneCorners = new Mat(4, 1, CvType.CV_32FC2);
    // Good corner coordinates detected in the scene, in pixels.
    private final Mat mSceneCorners = new Mat(0, 0, CvType.CV_32FC2);
    // The good detected corner coordinates, in pixels, as integers.
    private final MatOfPoint mIntSceneCorners = new MatOfPoint();

    // A grayscale version of the scene.
    private final Mat mGraySrc = new Mat();
    // Tentative matches of scene features and reference features.
    private final MatOfDMatch mMatches = new MatOfDMatch();

    // A feature detector, which finds features in images.
    private final FeatureDetector mFeatureDetector = FeatureDetector.create(FeatureDetector.ORB);
    // A descriptor extractor, which creates descriptors of
    // features.
    private final DescriptorExtractor mDescriptorExtractor = DescriptorExtractor.create(DescriptorExtractor.ORB);
    // A descriptor matcher, which matches features based on their
    // descriptors.
    private final DescriptorMatcher mDescriptorMatcher = DescriptorMatcher.create(DescriptorMatcher.BRUTEFORCE_HAMMINGLUT);

    // The color of the outline drawn around the detected image.
    private final Scalar mLineColor = new Scalar(0, 255, 0);

    public ImageDetectionFilter(final Context context, final int referenceImageResourceID) throws IOException {

        // Load the reference image from the app's resources.
        // It is loaded in BGR (blue, green, red) format.
        mReferenceImage = Utils.loadResource(context, referenceImageResourceID, Imgcodecs.CV_LOAD_IMAGE_COLOR);

        // Create grayscale and RGBA versions of the reference image.
        final Mat referenceImageGray = new Mat();
        Imgproc.cvtColor(mReferenceImage, referenceImageGray, Imgproc.COLOR_BGR2GRAY);
        Imgproc.cvtColor(mReferenceImage, mReferenceImage, Imgproc.COLOR_BGR2RGBA);

        // Store the reference image's corner coordinates, in pixels.
        mReferenceCorners.put(0, 0, new double[]{0.0, 0.0});
        mReferenceCorners.put(1, 0, new double[]{referenceImageGray.cols(), 0.0});
        mReferenceCorners.put(2, 0, new double[]{referenceImageGray.cols(), referenceImageGray.rows()});
        mReferenceCorners.put(3, 0, new double[]{0.0, referenceImageGray.rows()});

        // Detect the reference features and compute their
        // descriptors.
        mFeatureDetector.detect(referenceImageGray, mReferenceKeypoints);
        mDescriptorExtractor.compute(referenceImageGray, mReferenceKeypoints, mReferenceDescriptors);
    }

 
}