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42
43#ifndef __OPENCV_STITCHING_BLENDERS_HPP__
44#define __OPENCV_STITCHING_BLENDERS_HPP__
45
46#include "opencv2/core.hpp"
47
48namespace cv {
49namespace detail {
50
51//! @addtogroup stitching_blend
52//! @{
53
54/** @brief Base class for all blenders.
55
56Simple blender which puts one image over another
57*/
58class CV_EXPORTS Blender
59{
60public:
61    virtual ~Blender() {}
62
63    enum { NO, FEATHER, MULTI_BAND };
64    static Ptr<Blender> createDefault(int type, bool try_gpu = false);
65
66    /** @brief Prepares the blender for blending.
67
68    @param corners Source images top-left corners
69    @param sizes Source image sizes
70     */
71    void prepare(const std::vector<Point> &corners, const std::vector<Size> &sizes);
72    /** @overload */
73    virtual void prepare(Rect dst_roi);
74    /** @brief Processes the image.
75
76    @param img Source image
77    @param mask Source image mask
78    @param tl Source image top-left corners
79     */
80    virtual void feed(InputArray img, InputArray mask, Point tl);
81    /** @brief Blends and returns the final pano.
82
83    @param dst Final pano
84    @param dst_mask Final pano mask
85     */
86    virtual void blend(InputOutputArray dst, InputOutputArray dst_mask);
87
88protected:
89    UMat dst_, dst_mask_;
90    Rect dst_roi_;
91};
92
93/** @brief Simple blender which mixes images at its borders.
94 */
95class CV_EXPORTS FeatherBlender : public Blender
96{
97public:
98    FeatherBlender(float sharpness = 0.02f);
99
100    float sharpness() const { return sharpness_; }
101    void setSharpness(float val) { sharpness_ = val; }
102
103    void prepare(Rect dst_roi);
104    void feed(InputArray img, InputArray mask, Point tl);
105    void blend(InputOutputArray dst, InputOutputArray dst_mask);
106
107    //! Creates weight maps for fixed set of source images by their masks and top-left corners.
108    //! Final image can be obtained by simple weighting of the source images.
109    Rect createWeightMaps(const std::vector<UMat> &masks, const std::vector<Point> &corners,
110                          std::vector<UMat> &weight_maps);
111
112private:
113    float sharpness_;
114    UMat weight_map_;
115    UMat dst_weight_map_;
116};
117
118inline FeatherBlender::FeatherBlender(float _sharpness) { setSharpness(_sharpness); }
119
120/** @brief Blender which uses multi-band blending algorithm (see @cite BA83).
121 */
122class CV_EXPORTS MultiBandBlender : public Blender
123{
124public:
125    MultiBandBlender(int try_gpu = false, int num_bands = 5, int weight_type = CV_32F);
126
127    int numBands() const { return actual_num_bands_; }
128    void setNumBands(int val) { actual_num_bands_ = val; }
129
130    void prepare(Rect dst_roi);
131    void feed(InputArray img, InputArray mask, Point tl);
132    void blend(InputOutputArray dst, InputOutputArray dst_mask);
133
134private:
135    int actual_num_bands_, num_bands_;
136    std::vector<UMat> dst_pyr_laplace_;
137    std::vector<UMat> dst_band_weights_;
138    Rect dst_roi_final_;
139    bool can_use_gpu_;
140    int weight_type_; //CV_32F or CV_16S
141};
142
143
144//////////////////////////////////////////////////////////////////////////////
145// Auxiliary functions
146
147void CV_EXPORTS normalizeUsingWeightMap(InputArray weight, InputOutputArray src);
148
149void CV_EXPORTS createWeightMap(InputArray mask, float sharpness, InputOutputArray weight);
150
151void CV_EXPORTS createLaplacePyr(InputArray img, int num_levels, std::vector<UMat>& pyr);
152void CV_EXPORTS createLaplacePyrGpu(InputArray img, int num_levels, std::vector<UMat>& pyr);
153
154// Restores source image
155void CV_EXPORTS restoreImageFromLaplacePyr(std::vector<UMat>& pyr);
156void CV_EXPORTS restoreImageFromLaplacePyrGpu(std::vector<UMat>& pyr);
157
158//! @}
159
160} // namespace detail
161} // namespace cv
162
163#endif // __OPENCV_STITCHING_BLENDERS_HPP__
164