PARP Research Group

Universidad de Murcia

---

src/qvip/qvbriefdetector.h Go to the documentation of this file. /* * Copyright (C) 2012. PARP Research Group. * <http://perception.inf.um.es> * University of Murcia, Spain. * * This file is part of the QVision library. * * QVision is free software: you can redistribute it and/or modify * it under the terms of the GNU Lesser General Public License as * published by the Free Software Foundation, version 3 of the License. * * QVision is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public * License along with QVision. If not, see <http://www.gnu.org/licenses/>. */ #include <stdio.h> #include <stdlib.h> #include <iostream> #ifndef QVBRIEFDETECTOR_H #define QVBRIEFDETECTOR_H #include <QVImage> #include <QVKeypoint> #include <math.h> class QVBRIEFDetector { private: const unsigned int descriptorInts, numTests; const int windowRadius; public: QVector<char> coordinates; public: inline unsigned int getWindowRadius() const { return windowRadius; } inline unsigned int getNumTests() const { return numTests; } //inline unsigned int getDescriptorBytes() const { return descriptorInts; } inline unsigned int getDescriptorInts() const { return descriptorInts; } inline unsigned int distance(const QVector<unsigned int> &descriptorsA, const QVector<unsigned int> &descriptorsB, const int indexA = 0, const int indexB = 0) const { Q_ASSERT(descriptorsA.count() > descriptorInts * indexA); Q_ASSERT(descriptorsB.count() > descriptorInts * indexB); const unsigned int *dA = &(descriptorsA[descriptorInts*indexA]), *dB = &(descriptorsB[descriptorInts*indexB]); unsigned int count = 0; for(int i = 0; i < descriptorInts; i++) count += qvNiftyParallelBitCount(dA[i] xor dB[i]); return count; } QVBRIEFDetector(const unsigned int descriptorInts = 4, const unsigned int windowRadius = 16): descriptorInts(descriptorInts), numTests(descriptorInts*32), windowRadius(windowRadius), coordinates(numTests * 4) { if (windowRadius > 127) std::cout << "[QVBRIEFDetector0::QVBRIEFDetector0()] Error: Test distance must be less than 127." << std::endl; //for(unsigned int i = 0; i < coordinates[0].count(); i++) // coordinates[0][i] = rand()%(2*windowRadius) - windowRadius; for(unsigned int i = 0; i < numTests*4; i+=2) { const double random1 = double(random()%1000) / 1000.0, random2 = double(random()%500) / 1000.0 + 0.5; Q_ASSERT(random1 >= 0); Q_ASSERT(random2 >= 0); Q_ASSERT(random1 <= 1.0); Q_ASSERT(random2 <= 1.0); const double angle = 2.0 * PI * random1, dist = random2; const int x = qvSymmetricFloor(dist * cos(angle) * int(windowRadius)), y = qvSymmetricFloor(dist * sin(angle) * int(windowRadius)); Q_ASSERT(x >= -int(windowRadius)); Q_ASSERT(y >= -int(windowRadius)); Q_ASSERT(x <= +int(windowRadius)); Q_ASSERT(y <= +int(windowRadius)); coordinates[i+0] = x; coordinates[i+1] = y; } } QVector<unsigned int> getDescriptors( const QVImage<uChar, 1> &image, const QVector<QPointF> &keypoints, const unsigned int octave = 1) const { QVector<unsigned int> result(keypoints.count()*descriptorInts); const uChar *imgData = image.getReadData(); const int imgStep = image.getStep(), imgCols = image.getCols(), imgRows = image.getRows(); #ifdef DEBUG const uChar *imageDataLimit = imgData + imgStep * imgCols + imgRows; #endif // DEBUG // Get the binary descriptors for the keypoints. for(int index = 0; index < keypoints.count(); index++) { const QPointF &kp = keypoints[index]; //const int xCoor = kp.x(), //double(kp.x) / double(kp.scale), // yCoor = kp.y(); //double(kp.y) / double(kp.scale); const int xCoor = kp.x() / double(octave), yCoor = kp.y() / double(octave); // Expected range for the angle. //Q_ASSERT(kp.angle >= -PI); //Q_ASSERT(kp.angle <= +PI); const QVector<char> coors = coordinates; // Mind the image data boundaries. Q_ASSERT(xCoor - windowRadius >= 0); Q_ASSERT(yCoor - windowRadius >= 0); Q_ASSERT(xCoor + windowRadius < imgCols); Q_ASSERT(yCoor + windowRadius < imgRows); // Get the binary descriptor for the keypoint. const uChar *pixelPtr = imgData + imgStep * yCoor + xCoor; for(int b = 0; b < descriptorInts; b++) { Q_ASSERT(result.count() > descriptorInts*index+b); int ac = 0; unsigned int binaryDescriptor = 0; for(int i = 32*4*b; i < 32*4*(b+1); i+=4) { Q_ASSERT(i+3 < coors.count()); // Careful with the image data boundaries. Q_ASSERT(xCoor + coors[i+0] >= 0); Q_ASSERT(yCoor + coors[i+1] >= 0); Q_ASSERT(xCoor + coors[i+0] < imgCols); Q_ASSERT(yCoor + coors[i+1] < imgRows); Q_ASSERT(xCoor + coors[i+2] >= 0); Q_ASSERT(yCoor + coors[i+3] >= 0); Q_ASSERT(xCoor + coors[i+2] < imgCols); Q_ASSERT(yCoor + coors[i+3] < imgRows); Q_ASSERT(*(pixelPtr + imgStep * coors[i+1] + coors[i+0]) == pixelPtr[ imgStep * coors[i+1] + coors[i+0] ]); Q_ASSERT(*(pixelPtr + imgStep * coors[i+3] + coors[i+2]) == pixelPtr[ imgStep * coors[i+3] + coors[i+2] ]); // Shift binary descriptor, to make room for the result of the next binary test. binaryDescriptor <<=1; // Evaluate binary test. binaryDescriptor |= pixelPtr[ imgStep * coors[i+1] + coors[i+0] ] // First pixel in the binary test. > pixelPtr[ imgStep * coors[i+3] + coors[i+2] ]; // Second pixel in the binary test. } result[descriptorInts*index+b] = binaryDescriptor; } } return result; } }; bool saveBRIEFDescriptorsInLoweSIFTFileFormat(const QString fileName, const QVector<QPointF> features, const QVector<unsigned int> descriptors); #endif // QVBRIEFDETECTOR_H

---

QVision framework. PARP research group. Copyright © 2007, 2008, 2009, 2010, 2011.