ch.zhaw.facerecognitionlibrary.Helpers.MatOperation.java Source code

Introduction

Here is the source code for ch.zhaw.facerecognitionlibrary.Helpers.MatOperation.java

Source

/* Copyright 2016 Michael Sladoje and Mike Schlchli. All Rights Reserved.
    
Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at
    
http://www.apache.org/licenses/LICENSE-2.0
    
Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
==============================================================================*/

package ch.zhaw.facerecognitionlibrary.Helpers;

import org.opencv.core.Core;
import org.opencv.core.CvType;
import org.opencv.core.Mat;
import org.opencv.core.MatOfPoint;
import org.opencv.core.MatOfPoint2f;
import org.opencv.core.Point;
import org.opencv.core.Rect;
import org.opencv.core.Scalar;
import org.opencv.imgproc.Imgproc;

public class MatOperation {
    private static final Scalar FACE_RECT_COLOR = new Scalar(0, 255, 0, 255);
    private static final int FONT_SIZE = 5;
    private static final int THICKNESS = 3;

    /***************************************************************************************
     *    Title: Rotate image by 90, 180 or 270 degrees
     *    Author: StereoMatching
     *    Date: 29.04.2013
     *    Code version: -
     *    Availability: http://stackoverflow.com
     *
     ***************************************************************************************/

    public static void rotate_90n(Mat img, int angle) {
        if (angle == 270 || angle == -90) {
            // Rotate clockwise 270 degrees
            Core.transpose(img, img);
            Core.flip(img, img, 0);
        } else if (angle == 180 || angle == -180) {
            // Rotate clockwise 180 degrees
            Core.flip(img, img, -1);
        } else if (angle == 90 || angle == -270) {
            // Rotate clockwise 90 degrees
            Core.transpose(img, img);
            Core.flip(img, img, 1);
        }
    }

    public static Point drawRectangleOnPreview(Mat img, Rect face, boolean front_camera) {
        if (front_camera) {
            int topLeftX = (int) (img.cols() - (face.tl().x + face.width));
            int bottomRightX = (int) (img.cols() - (face.br().x) + face.width);
            Point tl = new Point(topLeftX, face.tl().y);
            Point br = new Point(bottomRightX, face.br().y);
            Imgproc.rectangle(img, tl, br, FACE_RECT_COLOR, THICKNESS);
            return tl;
        } else {
            Imgproc.rectangle(img, face.tl(), face.br(), FACE_RECT_COLOR, THICKNESS);
            return face.tl();
        }
    }

    public static void drawRectangleAndLabelOnPreview(Mat img, Rect face, String label, boolean front_camera) {
        Point tl = drawRectangleOnPreview(img, face, front_camera);
        Imgproc.putText(img, label, tl, Core.FONT_HERSHEY_PLAIN, FONT_SIZE, FACE_RECT_COLOR, THICKNESS);
    }

    public static Rect[] rotateFaces(Mat img, Rect[] faces, int angle) {
        Point center = new Point(img.cols() / 2, img.rows() / 2);
        Mat rotMat = Imgproc.getRotationMatrix2D(center, angle, 1);
        rotMat.convertTo(rotMat, CvType.CV_32FC1);
        float scale = img.cols() / img.rows();
        for (Rect face : faces) {
            Mat m = new Mat(3, 1, CvType.CV_32FC1);
            m.put(0, 0, face.x);
            m.put(1, 0, face.y);
            m.put(2, 0, 1);
            Mat res = Mat.zeros(2, 1, CvType.CV_32FC1);
            Core.gemm(rotMat, m, 1, new Mat(), 0, res, 0);
            face.x = (int) res.get(0, 0)[0];
            face.y = (int) res.get(1, 0)[0];
            if (angle == 270 || angle == -90) {
                face.x = (int) (face.x * scale - face.width);
                face.x = face.x + face.width / 4;
                face.y = face.y + face.height / 4;
            } else if (angle == 180 || angle == -180) {
                face.x = face.x - face.width;
                face.y = face.y - face.height;
            } else if (angle == 90 || angle == -270) {
                face.y = (int) (face.y * scale - face.height);
                face.x = face.x - face.width / 4;
                face.y = face.y - face.height / 4;
            }
        }
        return faces;
    }
}