| /* |
| * Copyright (C) 2011 The Android Open Source Project |
| * |
| * 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. |
| */ |
| |
| /*$Id: db_feature_detection.h,v 1.3 2011/06/17 14:03:30 mbansal Exp $*/ |
| |
| #ifndef DB_FEATURE_DETECTION_H |
| #define DB_FEATURE_DETECTION_H |
| |
| /***************************************************************** |
| * Lean and mean begins here * |
| *****************************************************************/ |
| /*! |
| * \defgroup FeatureDetection Feature Detection |
| */ |
| #include "db_utilities.h" |
| #include "db_utilities_constants.h" |
| #include <stdlib.h> //for NULL |
| |
| /*! |
| * \class db_CornerDetector_f |
| * \ingroup FeatureDetection |
| * \brief Harris corner detector for float images. |
| * |
| * This class performs Harris corner extraction on *float* images managed |
| * with functions in \ref LMImageBasicUtilities. |
| */ |
| class DB_API db_CornerDetector_f |
| { |
| public: |
| db_CornerDetector_f(); |
| ~db_CornerDetector_f(); |
| |
| /*! |
| * Set parameters and pre-allocate memory. Return an upper bound |
| * on the number of corners detected in one frame. |
| * \param im_width width |
| * \param im_height height |
| * \param target_nr_corners |
| * \param nr_horizontal_blocks |
| * \param nr_vertical_blocks |
| * \param absolute_threshold |
| * \param relative_threshold |
| */ |
| unsigned long Init(int im_width,int im_height, |
| int target_nr_corners=DB_DEFAULT_TARGET_NR_CORNERS, |
| int nr_horizontal_blocks=DB_DEFAULT_NR_FEATURE_BLOCKS, |
| int nr_vertical_blocks=DB_DEFAULT_NR_FEATURE_BLOCKS, |
| double absolute_threshold=DB_DEFAULT_ABS_CORNER_THRESHOLD, |
| double relative_threshold=DB_DEFAULT_REL_CORNER_THRESHOLD); |
| |
| /*! |
| * Detect the corners. |
| * x_coord and y_coord should be pre-allocated arrays of length returned by Init(). |
| * \param img row array pointer |
| * \param x_coord corner locations |
| * \param y_coord corner locations |
| * \param nr_corners actual number of corners computed |
| */ |
| void DetectCorners(const float * const *img,double *x_coord,double *y_coord,int *nr_corners) const; |
| void SetAbsoluteThreshold(double a_thresh) { m_a_thresh = a_thresh; }; |
| void SetRelativeThreshold(double r_thresh) { m_r_thresh = r_thresh; }; |
| protected: |
| void Clean(); |
| unsigned long Start(int im_width,int im_height, |
| int block_width,int block_height,unsigned long area_factor, |
| double absolute_threshold,double relative_threshold,int chunkwidth); |
| |
| int m_w,m_h,m_cw,m_bw,m_bh; |
| /*Area factor holds the maximum number of corners to detect |
| per 10000 pixels*/ |
| unsigned long m_area_factor,m_max_nr; |
| double m_a_thresh,m_r_thresh; |
| float *m_temp_f; |
| double *m_temp_d; |
| float **m_strength,*m_strength_mem; |
| }; |
| /*! |
| * \class db_CornerDetector_u |
| * \ingroup FeatureDetection |
| * \brief Harris corner detector for byte images. |
| * |
| * This class performs Harris corner extraction on *byte* images managed |
| * with functions in \ref LMImageBasicUtilities. |
| */ |
| class DB_API db_CornerDetector_u |
| { |
| public: |
| db_CornerDetector_u(); |
| virtual ~db_CornerDetector_u(); |
| |
| /*! |
| Copy ctor duplicates settings. |
| Memory is not copied. |
| */ |
| db_CornerDetector_u(const db_CornerDetector_u& cd); |
| /*! |
| Assignment optor duplicates settings. |
| Memory not copied. |
| */ |
| db_CornerDetector_u& operator=(const db_CornerDetector_u& cd); |
| |
| /*! |
| * Set parameters and pre-allocate memory. Return an upper bound |
| * on the number of corners detected in one frame |
| */ |
| virtual unsigned long Init(int im_width,int im_height, |
| int target_nr_corners=DB_DEFAULT_TARGET_NR_CORNERS, |
| int nr_horizontal_blocks=DB_DEFAULT_NR_FEATURE_BLOCKS, |
| int nr_vertical_blocks=DB_DEFAULT_NR_FEATURE_BLOCKS, |
| double absolute_threshold=DB_DEFAULT_ABS_CORNER_THRESHOLD, |
| double relative_threshold=DB_DEFAULT_REL_CORNER_THRESHOLD); |
| |
| /*! |
| * Detect the corners. |
| * Observe that the image should be overallocated by at least 256 bytes |
| * at the end. |
| * x_coord and y_coord should be pre-allocated arrays of length returned by Init(). |
| * Specifying image mask will restrict corner output to foreground regions. |
| * Foreground value can be specified using fgnd. By default any >0 mask value |
| * is considered to be foreground |
| * \param img row array pointer |
| * \param x_coord corner locations |
| * \param y_coord corner locations |
| * \param nr_corners actual number of corners computed |
| * \param msk row array pointer to mask image |
| * \param fgnd foreground value in the mask |
| */ |
| virtual void DetectCorners(const unsigned char * const *img,double *x_coord,double *y_coord,int *nr_corners, |
| const unsigned char * const * msk=NULL, unsigned char fgnd=255) const; |
| |
| /*! |
| Set absolute feature threshold |
| */ |
| virtual void SetAbsoluteThreshold(double a_thresh) { m_a_thresh = a_thresh; }; |
| /*! |
| Set relative feature threshold |
| */ |
| virtual void SetRelativeThreshold(double r_thresh) { m_r_thresh = r_thresh; }; |
| |
| /*! |
| Extract corners from a pre-computed strength image. |
| \param strength Harris strength image |
| \param x_coord corner locations |
| \param y_coord corner locations |
| \param nr_corners actual number of corners computed |
| */ |
| virtual void ExtractCorners(float ** strength, double *x_coord, double *y_coord, int *nr_corners); |
| protected: |
| virtual void Clean(); |
| /*The absolute threshold to this function should be 16.0 times |
| normal*/ |
| unsigned long Start(int im_width,int im_height, |
| int block_width,int block_height,unsigned long area_factor, |
| double absolute_threshold,double relative_threshold); |
| |
| int m_w,m_h,m_bw,m_bh; |
| /*Area factor holds the maximum number of corners to detect |
| per 10000 pixels*/ |
| unsigned long m_area_factor,m_max_nr; |
| double m_a_thresh,m_r_thresh; |
| int *m_temp_i; |
| double *m_temp_d; |
| float **m_strength,*m_strength_mem; |
| }; |
| |
| #endif /*DB_FEATURE_DETECTION_H*/ |
