1 /*
2  * Copyright (C) 2011 The Android Open Source Project
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  *      http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 
17 ///////////////////////////////////////////////////
18 // Align.h
19 // S.O. # :
20 // Author(s): zkira
21 // $Id: AlignFeatures.h,v 1.13 2011/06/17 13:35:47 mbansal Exp $
22 
23 #ifndef ALIGN_H
24 #define ALIGN_H
25 
26 #include "dbreg/dbreg.h"
27 #include <db_utilities_camera.h>
28 
29 #include "ImageUtils.h"
30 #include "MatrixUtils.h"
31 
32 class Align {
33 
34 public:
35   // Types of alignment possible
36   static const int ALIGN_TYPE_PAN    = 1;
37 
38   // Return codes
39   static const int ALIGN_RET_LOW_TEXTURE  = -2;
40   static const int ALIGN_RET_ERROR        = -1;
41   static const int ALIGN_RET_OK           = 0;
42   static const int ALIGN_RET_FEW_INLIERS  = 1;
43 
44   ///// Settings for feature-based alignment
45   // Number of features to use from corner detection
46   static const int DEFAULT_NR_CORNERS=750;
47   static const double DEFAULT_MAX_DISPARITY=0.1;//0.4;
48   // Type of homography to model
49   static const int DEFAULT_MOTION_MODEL=DB_HOMOGRAPHY_TYPE_R_T;
50 // static const int DEFAULT_MOTION_MODEL=DB_HOMOGRAPHY_TYPE_PROJECTIVE;
51 //  static const int DEFAULT_MOTION_MODEL=DB_HOMOGRAPHY_TYPE_AFFINE;
52   static const unsigned int DEFAULT_REFERENCE_UPDATE_PERIOD=1500; //  Manual reference frame update so set this to a large number
53 
54   static const int MIN_NR_REF_CORNERS = 25;
55   static const int MIN_NR_INLIERS = 10;
56 
57   Align();
58   ~Align();
59 
60   // Initialization of structures, etc.
61   int initialize(int width, int height, bool quarter_res, float thresh_still);
62 
63   // Add a frame.  Note: The alignment computation is performed
64   // in this function
65   int addFrameRGB(ImageType image);
66   int addFrame(ImageType image);
67 
68   // Obtain the TRS matrix from the last two frames
69   int getLastTRS(double trs[3][3]);
70   char* getRegProfileString();
71 
72 protected:
73 
74   db_FrameToReferenceRegistration reg;
75 
76   int frame_number;
77 
78   double Hcurr[9];   // Homography from the alignment reference to the frame-t
79   double Hprev[9];   // Homography from frame-0 to the frame-(t-1)
80 
81   int reference_frame_index; // Index of the reference frame from all captured frames
82   int num_frames_captured; // Total number of frames captured (different from frame_number)
83   double average_tx_per_frame; // Average pixel translation per captured frame
84 
85   int width,height;
86 
87   bool quarter_res;     // Whether to process at quarter resolution
88   float thresh_still;   // Translation threshold in pixels to detect still camera
89   ImageType imageGray;
90 };
91 
92 
93 #endif
94