root/modules/photo/src/align.cpp

/* [<][>][^][v][top][bottom][index][help] */

DEFINITIONS

This source file includes following definitions.
  1. cut
  2. process
  3. process
  4. calculateShift
  5. shiftMat
  6. getMaxBits
  7. setMaxBits
  8. getExcludeRange
  9. setExcludeRange
  10. getCut
  11. setCut
  12. write
  13. read
  14. computeBitmaps
  15. downsample
  16. buildPyr
  17. getMedian
  18. createAlignMTB

/*M///////////////////////////////////////////////////////////////////////////////////////
//
//  IMPORTANT: READ BEFORE DOWNLOADING, COPYING, INSTALLING OR USING.
//
//  By downloading, copying, installing or using the software you agree to this license.
//  If you do not agree to this license, do not download, install,
//  copy or use the software.
//
//
//                           License Agreement
//                For Open Source Computer Vision Library
//
// Copyright (C) 2013, OpenCV Foundation, all rights reserved.
// Third party copyrights are property of their respective owners.
//
// Redistribution and use in source and binary forms, with or without modification,
// are permitted provided that the following conditions are met:
//
//   * Redistribution's of source code must retain the above copyright notice,
//     this list of conditions and the following disclaimer.
//
//   * Redistribution's in binary form must reproduce the above copyright notice,
//     this list of conditions and the following disclaimer in the documentation
//     and/or other materials provided with the distribution.
//
//   * The name of the copyright holders may not be used to endorse or promote products
//     derived from this software without specific prior written permission.
//
// This software is provided by the copyright holders and contributors "as is" and
// any express or implied warranties, including, but not limited to, the implied
// warranties of merchantability and fitness for a particular purpose are disclaimed.
// In no event shall the Intel Corporation or contributors be liable for any direct,
// indirect, incidental, special, exemplary, or consequential damages
// (including, but not limited to, procurement of substitute goods or services;
// loss of use, data, or profits; or business interruption) however caused
// and on any theory of liability, whether in contract, strict liability,
// or tort (including negligence or otherwise) arising in any way out of
// the use of this software, even if advised of the possibility of such damage.
//
//M*/

#include "precomp.hpp"
#include "opencv2/photo.hpp"
#include "opencv2/imgproc.hpp"
#include "hdr_common.hpp"

namespace cv
{

class AlignMTBImpl : public AlignMTB
{
public:
    AlignMTBImpl(int _max_bits, int _exclude_range, bool _cut) :
        name("AlignMTB"),
        max_bits(_max_bits),
        exclude_range(_exclude_range),
        cut(_cut)
    {
    }

    void process(InputArrayOfArrays src, std::vector<Mat>& dst,
                 InputArray, InputArray)
    {
        process(src, dst);
    }

    void process(InputArrayOfArrays _src, std::vector<Mat>& dst)
    {
        std::vector<Mat> src;
        _src.getMatVector(src);

        checkImageDimensions(src);
        dst.resize(src.size());

        size_t pivot = src.size() / 2;
        dst[pivot] = src[pivot];
        Mat gray_base;
        cvtColor(src[pivot], gray_base, COLOR_RGB2GRAY);
        std::vector<Point> shifts;

        for(size_t i = 0; i < src.size(); i++) {
            if(i == pivot) {
                shifts.push_back(Point(0, 0));
                continue;
            }
            Mat gray;
            cvtColor(src[i], gray, COLOR_RGB2GRAY);
            Point shift = calculateShift(gray_base, gray);
            shifts.push_back(shift);
            shiftMat(src[i], dst[i], shift);
        }
        if(cut) {
            Point max(0, 0), min(0, 0);
            for(size_t i = 0; i < shifts.size(); i++) {
                if(shifts[i].x > max.x) {
                    max.x = shifts[i].x;
                }
                if(shifts[i].y > max.y) {
                    max.y = shifts[i].y;
                }
                if(shifts[i].x < min.x) {
                    min.x = shifts[i].x;
                }
                if(shifts[i].y < min.y) {
                    min.y = shifts[i].y;
                }
            }
            Point size = dst[0].size();
            for(size_t i = 0; i < dst.size(); i++) {
                dst[i] = dst[i](Rect(max, min + size));
            }
        }
    }

    Point calculateShift(InputArray _img0, InputArray _img1)
    {
        Mat img0 = _img0.getMat();
        Mat img1 = _img1.getMat();
        CV_Assert(img0.channels() == 1 && img0.type() == img1.type());
        CV_Assert(img0.size() == img0.size());

        int maxlevel = static_cast<int>(log((double)max(img0.rows, img0.cols)) / log(2.0)) - 1;
        maxlevel = min(maxlevel, max_bits - 1);

        std::vector<Mat> pyr0;
        std::vector<Mat> pyr1;
        buildPyr(img0, pyr0, maxlevel);
        buildPyr(img1, pyr1, maxlevel);

        Point shift(0, 0);
        for(int level = maxlevel; level >= 0; level--) {

            shift *= 2;
            Mat tb1, tb2, eb1, eb2;
            computeBitmaps(pyr0[level], tb1, eb1);
            computeBitmaps(pyr1[level], tb2, eb2);

            int min_err = (int)pyr0[level].total();
            Point new_shift(shift);
            for(int i = -1; i <= 1; i++) {
                for(int j = -1; j <= 1; j++) {
                    Point test_shift = shift + Point(i, j);
                    Mat shifted_tb2, shifted_eb2, diff;
                    shiftMat(tb2, shifted_tb2, test_shift);
                    shiftMat(eb2, shifted_eb2, test_shift);
                    bitwise_xor(tb1, shifted_tb2, diff);
                    bitwise_and(diff, eb1, diff);
                    bitwise_and(diff, shifted_eb2, diff);
                    int err = countNonZero(diff);
                    if(err < min_err) {
                        new_shift = test_shift;
                        min_err = err;
                    }
                }
            }
            shift = new_shift;
        }
        return shift;
    }

    void shiftMat(InputArray _src, OutputArray _dst, const Point shift)
    {
        Mat src = _src.getMat();
        _dst.create(src.size(), src.type());
        Mat dst = _dst.getMat();

        Mat res = Mat::zeros(src.size(), src.type());
        int width = src.cols - abs(shift.x);
        int height = src.rows - abs(shift.y);
        Rect dst_rect(max(shift.x, 0), max(shift.y, 0), width, height);
        Rect src_rect(max(-shift.x, 0), max(-shift.y, 0), width, height);
        src(src_rect).copyTo(res(dst_rect));
        res.copyTo(dst);
    }

    int getMaxBits() const { return max_bits; }
    void setMaxBits(int val) { max_bits = val; }

    int getExcludeRange() const { return exclude_range; }
    void setExcludeRange(int val) { exclude_range = val; }

    bool getCut() const { return cut; }
    void setCut(bool val) { cut = val; }

    void write(FileStorage& fs) const
    {
        fs << "name" << name
           << "max_bits" << max_bits
           << "exclude_range" << exclude_range
           << "cut" << static_cast<int>(cut);
    }

    void read(const FileNode& fn)
    {
        FileNode n = fn["name"];
        CV_Assert(n.isString() && String(n) == name);
        max_bits = fn["max_bits"];
        exclude_range = fn["exclude_range"];
        int cut_val = fn["cut"];
        cut = (cut_val != 0);
    }

    void computeBitmaps(InputArray _img, OutputArray _tb, OutputArray _eb)
    {
        Mat img = _img.getMat();
        _tb.create(img.size(), CV_8U);
        _eb.create(img.size(), CV_8U);
        Mat tb = _tb.getMat(), eb = _eb.getMat();
        int median = getMedian(img);
        compare(img, median, tb, CMP_GT);
        compare(abs(img - median), exclude_range, eb, CMP_GT);
    }

protected:
    String name;
    int max_bits, exclude_range;
    bool cut;

    void downsample(Mat& src, Mat& dst)
    {
        dst = Mat(src.rows / 2, src.cols / 2, CV_8UC1);

        int offset = src.cols * 2;
        uchar *src_ptr = src.ptr();
        uchar *dst_ptr = dst.ptr();
        for(int y = 0; y < dst.rows; y ++) {
            uchar *ptr = src_ptr;
            for(int x = 0; x < dst.cols; x++) {
                dst_ptr[0] = ptr[0];
                dst_ptr++;
                ptr += 2;
            }
            src_ptr += offset;
        }
    }

    void buildPyr(Mat& img, std::vector<Mat>& pyr, int maxlevel)
    {
        pyr.resize(maxlevel + 1);
        pyr[0] = img.clone();
        for(int level = 0; level < maxlevel; level++) {
            downsample(pyr[level], pyr[level + 1]);
        }
    }

    int getMedian(Mat& img)
    {
        int channels = 0;
        Mat hist;
        int hist_size = LDR_SIZE;
        float range[] = {0, LDR_SIZE} ;
        const float* ranges[] = {range};
        calcHist(&img, 1, &channels, Mat(), hist, 1, &hist_size, ranges);
        float *ptr = hist.ptr<float>();
        int median = 0, sum = 0;
        int thresh = (int)img.total() / 2;
        while(sum < thresh && median < LDR_SIZE) {
            sum += static_cast<int>(ptr[median]);
            median++;
        }
        return median;
    }
};

Ptr<AlignMTB> createAlignMTB(int max_bits, int exclude_range, bool cut)
{
    return makePtr<AlignMTBImpl>(max_bits, exclude_range, cut);
}

}

/* [<][>][^][v][top][bottom][index][help] */