samples/cpp/image_alignment.cpp

一个使用图像对齐ECC算法的示例

/*
* 本示例演示了函数的使用
* findTransformECC，它实现了图像对齐ECC算法
*
*
* 此演示加载一张图像（默认为fruits.jpg），并根据给定的运动类型人工创建
* 一个模板图像。当给出两张图像时，
* 第一张图像是输入图像，第二张定义了模板图像。
* 在后一种情况下，您还可以解析变换的初始化。
*
* 输入和输出变换文件包含原始变换（转换）元素
*
* 作者：G. Evangelidis, INRIA, 格勒诺布尔, 法国
* M. Asbach, Fraunhofer IAIS, 圣奥古斯丁, 德国
*/
#include <opencv2/imgcodecs.hpp>
#include <opencv2/highgui.hpp>
#include <opencv2/video.hpp>
#include <opencv2/imgproc.hpp>
#include <opencv2/core/utility.hpp>
 
#include <stdio.h>
#include <string>
#include <time.h>
#include <iostream>
#include <fstream>
 
using namespace cv;
using namespace std;
 
static void help(const char** argv);
static int readWarp(string iFilename, Mat& warp, int motionType);
static int saveWarp(string fileName, const Mat& warp, int motionType);
static void draw_warped_roi(Mat& image, const int width, const int height, Mat& W);
 
#define HOMO_VECTOR(H, x, y)\
H.at<float>(0,0) = (float)(x);\
H.at<float>(1,0) = (float)(y);\
H.at<float>(2,0) = 1.;
 
#define GET_HOMO_VALUES(X, x, y)\
(x) = static_cast<float> (X.at<float>(0,0)/X.at<float>(2,0));\
(y) = static_cast<float> (X.at<float>(1,0)/X.at<float>(2,0));
 
 
const std::string keys =
    "{@inputImage | fruits.jpg | 输入图像文件名 }"
    "{@templateImage | | 模板图像文件名 (可选)}"
    "{@inputWarp | | 输入变换（矩阵）文件名 (可选)}"
    "{n numOfIter | 50 | ECC迭代次数 }"
    "{e epsilon | 0.0001 | ECC收敛阈值 }"
    "{o outputWarp | outWarp.ecc | 输出变换（矩阵）文件名 }"
    "{m motionType | affine | 运动类型 (平移, 欧几里得, 仿射, 单应性) }"
    "{v verbose | 1 | 显示初始和最终图像 }"
    "{w warpedImfile | warpedECC.png | 变形后的输入图像 }"
    "{h help | | 打印帮助信息 }"
;
 
 
static void help(const char** argv)
{
 
cout << "\n此文件演示了ECC图像对齐算法的使用。当只给定一张图像时，"
        " 模板图像会通过随机变换人工生成。当给定两张图像时，"
        " 可以通过命令行解析来初始化变换。 "
        "\n如果缺少inputWarp，算法将使用单位变换进行初始化。 \n" << endl;
 
cout << "\n使用示例（一张图像）： \n"
<< argv[0]
<< " fruits.jpg -o=outWarp.ecc "
            "-m=euclidean -e=1e-6 -N=70 -v=1 \n" << endl;
 
cout << "\n使用示例（两张图像及初始化）： \n"
<< argv[0]
<< " yourInput.png yourTemplate.png "
        "yourInitialWarp.ecc -o=outWarp.ecc -m=homography -e=1e-6 -N=70 -v=1 -w=yourFinalImage.png \n" << endl;
 
}
 
static int readWarp(string iFilename, Mat& warp, int motionType){
 
    // 从文件中读取特定数量的原始值
    // 单应性为9个值，否则为6个
    CV_Assert(warp.type()==CV_32FC1);
    int numOfElements;
    if (motionType==MOTION_HOMOGRAPHY)
numOfElements=9;
    else
numOfElements=6;
 
    int i;
    int ret_value;
 
ifstream myfile(iFilename.c_str());
    if (myfile.is_open()){
        float* matPtr = warp.ptr<float>(0);
        for(i=0; i<numOfElements; i++){
myfile >> matPtr[i];
        }
ret_value = 1;
    }
    else {
cout << "无法打开文件 " << iFilename.c_str() << endl;
ret_value = 0;
    }
    return ret_value;
}
 
static int saveWarp(string fileName, const Mat& warp, int motionType)
{
    // 将原始矩阵元素保存到文件
    CV_Assert(warp.type()==CV_32FC1);
 
    const float* matPtr = warp.ptr<float>(0);
    int ret_value;
 
ofstream outfile(fileName.c_str());
    if( !outfile ) {
cerr << "保存时出错 "
<< "无法打开文件 '" << fileName.c_str() << "'!" << endl;
ret_value = 0;
    }
    else {//保存变换元素
outfile << matPtr[0] << " " << matPtr[1] << " " << matPtr[2] << endl;
outfile << matPtr[3] << " " << matPtr[4] << " " << matPtr[5] << endl;
        if (motionType==MOTION_HOMOGRAPHY){
outfile << matPtr[6] << " " << matPtr[7] << " " << matPtr[8] << endl;
        }
ret_value = 1;
    }
    return ret_value;
 
}
 
 
static void draw_warped_roi(Mat& image, const int width, const int height, Mat& W)
{
    Point2f top_left, top_right, bottom_left, bottom_right;
 
    Mat H = Mat (3, 1, CV_32F);
    Mat U = Mat (3, 1, CV_32F);
 
    Mat warp_mat = Mat::eye (3, 3, CV_32F);
 
    for (int y = 0; y < W.rows; y++)
        for (int x = 0; x < W.cols; x++)
warp_mat.at<float>(y,x) = W.at<float>(y,x);
 
    // 变换矩形的角点
 
    // 左上角
HOMO_VECTOR(H, 1, 1);
    gemm(warp_mat, H, 1, 0, 0, U);
GET_HOMO_VALUES(U, top_left.x, top_left.y);
 
    // 右上角
HOMO_VECTOR(H, width, 1);
    gemm(warp_mat, H, 1, 0, 0, U);
GET_HOMO_VALUES(U, top_right.x, top_right.y);
 
    // 左下角
HOMO_VECTOR(H, 1, height);
    gemm(warp_mat, H, 1, 0, 0, U);
GET_HOMO_VALUES(U, bottom_left.x, bottom_left.y);
 
    // 右下角
HOMO_VECTOR(H, width, height);
    gemm(warp_mat, H, 1, 0, 0, U);
GET_HOMO_VALUES(U, bottom_right.x, bottom_right.y);
 
    // 绘制变换后的周长
    line(image, top_left, top_right, Scalar(255));
    line(image, top_right, bottom_right, Scalar(255));
    line(image, bottom_right, bottom_left, Scalar(255));
    line(image, bottom_left, top_left, Scalar(255));
}
 
int main (const int argc, const char * argv[])
{
 
    CommandLineParser parser(argc, argv, keys);
parser.about("ECC 演示");
 
parser.printMessage();
help(argv);
 
    string imgFile = parser.get<string>(0);
    string tempImgFile = parser.get<string>(1);
    string inWarpFile = parser.get<string>(2);
 
    int number_of_iterations = parser.get<int>("n");
    double termination_eps = parser.get<double>("e");
    string warpType = parser.get<string>("m");
    int verbose = parser.get<int>("v");
    string finalWarp = parser.get<string>("o");
    string warpedImFile = parser.get<string>("w");
    if (!parser.check())
    {
parser.printErrors();
        return -1;
    }
    if (!(warpType == "translation" || warpType == "euclidean"
|| warpType == "affine" || warpType == "homography"))
    {
cerr << "无效的运动变换" << endl;
        return -1;
    }
 
    int mode_temp;
    if (warpType == "translation")
mode_temp = MOTION_TRANSLATION;
    else if (warpType == "euclidean")
mode_temp = MOTION_EUCLIDEAN;
    else if (warpType == "affine")
mode_temp = MOTION_AFFINE;
    else
mode_temp = MOTION_HOMOGRAPHY;
 
    Mat inputImage = imread(samples::findFile(imgFile), IMREAD_GRAYSCALE);
    if (inputImage.empty())
    {
cerr << "无法加载输入图像" << endl;
        return -1;
    }
 
    Mat target_image;
    Mat template_image;
 
    if (tempImgFile!="") {
inputImage.copyTo(target_image);
template_image = imread(samples::findFile(tempImgFile), IMREAD_GRAYSCALE);
        if (template_image.empty()){
cerr << "无法加载模板图像" << endl;
            return -1;
        }
 
    }
    else{ //对输入图像应用随机变换
        resize(inputImage, target_image, Size(216, 216), 0, 0, INTER_LINEAR_EXACT);
        Mat warpGround;
        RNG rng(getTickCount());
        double angle;
        switch (mode_temp) {
        case MOTION_TRANSLATION
warpGround = (Mat_<float>(2,3) << 1, 0, (rng.uniform(10.f, 20.f)),
0, 1, (rng.uniform(10.f, 20.f)));
            warpAffine(target_image, template_image, warpGround,
                Size(200,200), INTER_LINEAR + WARP_INVERSE_MAP);
            break;
        case MOTION_EUCLIDEAN
angle = CV_PI/30 + CV_PI*rng.uniform((double)-2.f, (double)2.f)/180;
 
warpGround = (Mat_<float>(2,3) << cos(angle), -sin(angle), (rng.uniform(10.f, 20.f)),
                sin(angle), cos(angle), (rng.uniform(10.f, 20.f)));
            warpAffine(target_image, template_image, warpGround,
                Size(200,200), INTER_LINEAR + WARP_INVERSE_MAP);
            break;
        case MOTION_AFFINE
 
warpGround = (Mat_<float>(2,3) << (1-rng.uniform(-0.05f, 0.05f)),
(rng.uniform(-0.03f, 0.03f)), (rng.uniform(10.f, 20.f)),
(rng.uniform(-0.03f, 0.03f)), (1-rng.uniform(-0.05f, 0.05f)),
(rng.uniform(10.f, 20.f)));
            warpAffine(target_image, template_image, warpGround,
                Size(200,200), INTER_LINEAR + WARP_INVERSE_MAP);
            break;
        case MOTION_HOMOGRAPHY
warpGround = (Mat_<float>(3,3) << (1-rng.uniform(-0.05f, 0.05f)),
(rng.uniform(-0.03f, 0.03f)), (rng.uniform(10.f, 20.f)),
(rng.uniform(-0.03f, 0.03f)), (1-rng.uniform(-0.05f, 0.05f)),(rng.uniform(10.f, 20.f)),
(rng.uniform(0.0001f, 0.0003f)), (rng.uniform(0.0001f, 0.0003f)), 1.f);
            warpPerspective(target_image, template_image, warpGround,
                Size(200,200), INTER_LINEAR + WARP_INVERSE_MAP);
            break;
        }
    }
 
 
    const int warp_mode = mode_temp;
 
    // 初始化或加载变换矩阵
    Mat warp_matrix;
    if (warpType == "homography")
warp_matrix = Mat::eye(3, 3, CV_32F);
    else
warp_matrix = Mat::eye(2, 3, CV_32F);
 
    if (inWarpFile!=""){
        int readflag = readWarp(inWarpFile, warp_matrix, warp_mode);
        if ((!readflag) || warp_matrix.empty())
        {
cerr << "-> 检查变换初始化文件" << endl << flush;
            return -1;
        }
    }
    else {
 
printf("\n ->性能警告：理想情况下，单位变换假定图像尺寸"
            "相似。如果变形强烈，单位变换可能不是"
            "一个好的初始化。 \n");
 
    }
 
    if (number_of_iterations > 200)
cout << "-> 警告：迭代次数过多 " << endl;
 
    if (warp_mode != MOTION_HOMOGRAPHY)
warp_matrix.rows = 2;
 
    // 开始计时
    const double tic_init = (double) getTickCount ();
    double cc = findTransformECC (template_image, target_image, warp_matrix, warp_mode,
        TermCriteria (TermCriteria::COUNT+TermCriteria::EPS,
number_of_iterations, termination_eps));
 
    if (cc == -1)
    {
cerr << "执行被中断。相关值将最小化。" << endl;
cerr << "检查变换初始化和/或图像尺寸。" << endl << flush;
    }
 
    // 结束计时
    const double toc_final = (double) getTickCount ();
    const double total_time = (toc_final-tic_init)/(getTickFrequency());
    if (verbose){
cout << "对齐时间 (" << warpType << " 变换): "
<< total_time << " 秒" << endl << flush;
        // cout << "最终相关性: " << cc << endl << flush;
 
    }
 
    // 保存最终变换矩阵
saveWarp(finalWarp, warp_matrix, warp_mode);
 
    if (verbose){
cout << "\n最终变换已保存到文件: " << finalWarp << endl << flush;
    }
 
    // 保存最终变形图像
    Mat warped_image = Mat(template_image.rows, template_image.cols, CV_32FC1);
    if (warp_mode != MOTION_HOMOGRAPHY)
        warpAffine (target_image, warped_image, warp_matrix, warped_image.size(),
INTER_LINEAR + WARP_INVERSE_MAP);
    else
        warpPerspective (target_image, warped_image, warp_matrix, warped_image.size(),
INTER_LINEAR + WARP_INVERSE_MAP);
 
    // 保存变形图像
    imwrite(warpedImFile, warped_image);
 
    // 显示结果图像
    if (verbose)
    {
 
cout << "变形图像已保存到文件: " << warpedImFile << endl << flush;
 
        namedWindow ("图像", WINDOW_AUTOSIZE);
        namedWindow ("模板", WINDOW_AUTOSIZE);
        namedWindow ("变形图像", WINDOW_AUTOSIZE);
        namedWindow ("误差 (黑色: 无误差)", WINDOW_AUTOSIZE);
 
        moveWindow ("图像", 20, 300);
        moveWindow ("模板", 300, 300);
        moveWindow ("变形图像", 600, 300);
        moveWindow ("误差 (黑色: 无误差)", 900, 300);
 
        // 绘制对应区域的边界
        Mat identity_matrix = Mat::eye(3,3,CV_32F);
 
draw_warped_roi (target_image, template_image.cols-2, template_image.rows-2, warp_matrix);
draw_warped_roi (template_image, template_image.cols-2, template_image.rows-2, identity_matrix);
 
        Mat errorImage;
        subtract(template_image, warped_image, errorImage);
        double max_of_error;
        minMaxLoc(errorImage, NULL, &max_of_error);
 
        // 显示图像
cout << "按任意键退出演示（您可能需要先点击图像）。" << endl << flush;
 
        imshow ("图像", target_image);
        waitKey (200);
        imshow ("模板", template_image);
        waitKey (200);
        imshow ("变形图像", warped_image);
        waitKey(200);
        imshow ("误差 (黑色: 无误差)", abs(errorImage)*255/max_of_error);
        waitKey(0);
 
    }
 
    // 完成
    return 0;
}