flow_estimation.h (3175B)
1 /* 2 * Copyright (c) 2016, Alliance for Open Media. All rights reserved. 3 * 4 * This source code is subject to the terms of the BSD 2 Clause License and 5 * the Alliance for Open Media Patent License 1.0. If the BSD 2 Clause License 6 * was not distributed with this source code in the LICENSE file, you can 7 * obtain it at www.aomedia.org/license/software. If the Alliance for Open 8 * Media Patent License 1.0 was not distributed with this source code in the 9 * PATENTS file, you can obtain it at www.aomedia.org/license/patent. 10 */ 11 12 #ifndef AOM_AOM_DSP_FLOW_ESTIMATION_H_ 13 #define AOM_AOM_DSP_FLOW_ESTIMATION_H_ 14 15 #include "aom_dsp/pyramid.h" 16 #include "aom_dsp/flow_estimation/corner_detect.h" 17 #include "aom_ports/mem.h" 18 #include "aom_scale/yv12config.h" 19 20 #ifdef __cplusplus 21 extern "C" { 22 #endif 23 24 #define MAX_PARAMDIM 6 25 #define MIN_INLIER_PROB 0.1 26 27 /* clang-format off */ 28 enum { 29 IDENTITY = 0, // identity transformation, 0-parameter 30 TRANSLATION = 1, // translational motion 2-parameter 31 ROTZOOM = 2, // simplified affine with rotation + zoom only, 4-parameter 32 AFFINE = 3, // affine, 6-parameter 33 TRANS_TYPES, 34 } UENUM1BYTE(TransformationType); 35 /* clang-format on */ 36 37 // number of parameters used by each transformation in TransformationTypes 38 static const int trans_model_params[TRANS_TYPES] = { 0, 2, 4, 6 }; 39 40 // Available methods which can be used for global motion estimation 41 typedef enum { 42 GLOBAL_MOTION_METHOD_FEATURE_MATCH, 43 GLOBAL_MOTION_METHOD_DISFLOW, 44 GLOBAL_MOTION_METHOD_LAST = GLOBAL_MOTION_METHOD_DISFLOW, 45 GLOBAL_MOTION_METHODS 46 } GlobalMotionMethod; 47 48 typedef struct { 49 double params[MAX_PARAMDIM]; 50 int *inliers; 51 int num_inliers; 52 } MotionModel; 53 54 // Data structure to store a single correspondence point during global 55 // motion search. 56 // 57 // A correspondence (x, y) -> (rx, ry) means that point (x, y) in the 58 // source frame corresponds to point (rx, ry) in the ref frame. 59 typedef struct { 60 double x, y; 61 double rx, ry; 62 } Correspondence; 63 64 // Which global motion method should we use in practice? 65 // Disflow is both faster and gives better results than feature matching in 66 // practically all cases, so we use disflow by default 67 static const GlobalMotionMethod default_global_motion_method = 68 GLOBAL_MOTION_METHOD_DISFLOW; 69 70 extern const double kIdentityParams[MAX_PARAMDIM]; 71 72 // Compute a global motion model between the given source and ref frames. 73 // 74 // As is standard for video codecs, the resulting model maps from (x, y) 75 // coordinates in `src` to the corresponding points in `ref`, regardless 76 // of the temporal order of the two frames. 77 // 78 // Returns true if global motion estimation succeeded, false if not. 79 // The output models should only be used if this function succeeds. 80 bool aom_compute_global_motion(TransformationType type, YV12_BUFFER_CONFIG *src, 81 YV12_BUFFER_CONFIG *ref, int bit_depth, 82 GlobalMotionMethod gm_method, 83 int downsample_level, MotionModel *motion_models, 84 int num_motion_models, bool *mem_alloc_failed); 85 86 #ifdef __cplusplus 87 } 88 #endif 89 90 #endif // AOM_AOM_DSP_FLOW_ESTIMATION_H_