opticflow_calculator.c File Reference

Estimate velocity from optic flow. More...

#include "std.h"
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include "opticflow_calculator.h"
#include "lib/vision/image.h"
#include "lib/vision/lucas_kanade.h"
#include "lib/vision/fast_rosten.h"
#include "size_divergence.h"
#include "linear_flow_fit.h"

Include dependency graph for opticflow_calculator.c:

Go to the source code of this file.

Macros
#define	SIZE_DIV   1
#define	LINEAR_FIT   1
#define	OPTICFLOW_FOV_W   0.89360857702
#define	OPTICFLOW_FOV_H   0.67020643276
#define	OPTICFLOW_FX   343.1211
#define	OPTICFLOW_FY   348.5053
#define	OPTICFLOW_MAX_TRACK_CORNERS   25
#define	OPTICFLOW_WINDOW_SIZE   10
#define	OPTICFLOW_SUBPIXEL_FACTOR   10
#define	OPTICFLOW_MAX_ITERATIONS   10
#define	OPTICFLOW_THRESHOLD_VEC   2
#define	OPTICFLOW_FAST9_ADAPTIVE   TRUE
#define	OPTICFLOW_FAST9_THRESHOLD   20
#define	OPTICFLOW_FAST9_MIN_DISTANCE   10

Functions
static uint32_t	timeval_diff (struct timeval *starttime, struct timeval *finishtime)
	Calculate the difference from start till finish. More...
static int	cmp_flow (const void *a, const void *b)
	Compare two flow vectors based on flow distance Used for sorting. More...
void	opticflow_calc_init (struct opticflow_t *opticflow, uint16_t w, uint16_t h)
	Initialize the opticflow calculator. More...
void	opticflow_calc_frame (struct opticflow_t *opticflow, struct opticflow_state_t *state, struct image_t *img, struct opticflow_result_t *result)
	Run the optical flow on a new image frame. More...

Detailed Description

Estimate velocity from optic flow.

Using images from a vertical camera and IMU sensor data.

Definition in file opticflow_calculator.c.

Macro Definition Documentation

#define LINEAR_FIT   1

Definition at line 51 of file opticflow_calculator.c.

Referenced by opticflow_calc_frame().

#define OPTICFLOW_FAST9_ADAPTIVE   TRUE

Definition at line 101 of file opticflow_calculator.c.

Referenced by opticflow_calc_init().

#define OPTICFLOW_FAST9_MIN_DISTANCE   10

Definition at line 111 of file opticflow_calculator.c.

Referenced by opticflow_calc_init().

#define OPTICFLOW_FAST9_THRESHOLD   20

Definition at line 106 of file opticflow_calculator.c.

Referenced by opticflow_calc_init().

#define OPTICFLOW_FOV_H   0.67020643276

Definition at line 60 of file opticflow_calculator.c.

Referenced by opticflow_calc_frame().

#define OPTICFLOW_FOV_W   0.89360857702

Definition at line 55 of file opticflow_calculator.c.

Referenced by opticflow_calc_frame().

#define OPTICFLOW_FX   343.1211

Definition at line 65 of file opticflow_calculator.c.

Referenced by opticflow_calc_frame().

#define OPTICFLOW_FY   348.5053

Definition at line 70 of file opticflow_calculator.c.

Referenced by opticflow_calc_frame().

#define OPTICFLOW_MAX_ITERATIONS   10

Definition at line 91 of file opticflow_calculator.c.

Referenced by opticflow_calc_init().

#define OPTICFLOW_MAX_TRACK_CORNERS   25

Definition at line 76 of file opticflow_calculator.c.

Referenced by opticflow_calc_init().

#define OPTICFLOW_SUBPIXEL_FACTOR   10

Definition at line 86 of file opticflow_calculator.c.

Referenced by opticflow_calc_init().

#define OPTICFLOW_THRESHOLD_VEC   2

Definition at line 96 of file opticflow_calculator.c.

Referenced by opticflow_calc_init().

#define OPTICFLOW_WINDOW_SIZE   10

Definition at line 81 of file opticflow_calculator.c.

Referenced by opticflow_calc_init().

#define SIZE_DIV   1

Definition at line 48 of file opticflow_calculator.c.

Referenced by opticflow_calc_frame().

Function Documentation

static int cmp_flow ( const void *  a, const void *  b  )

static

Compare two flow vectors based on flow distance Used for sorting.

Parameters

[in]	*a	The first flow vector (should be vect flow_t)
[in]	*b	The second flow vector (should be vect flow_t)

Returns

Negative if b has more flow than a, 0 if the same and positive if a has more flow than b

Definition at line 331 of file opticflow_calculator.c.

References flow_t::flow_x, and flow_t::flow_y.

Referenced by opticflow_calc_frame().

Here is the caller graph for this function:

void opticflow_calc_frame	(	struct opticflow_t *	opticflow,
		struct opticflow_state_t *	state,
		struct image_t *	img,
		struct opticflow_result_t *	result
	)

Run the optical flow on a new image frame.

Parameters

[in]	*opticflow	The opticalflow structure that keeps track of previous images
[in]	*state	The state of the drone
[in]	*img	The image frame to calculate the optical flow from
[out]	*result	The optical flow result

Definition at line 155 of file opticflow_calculator.c.

References opticflow_state_t::agl, analyze_linear_flow_field(), cmp_flow(), opticflow_result_t::corner_cnt, opticflow_result_t::div_size, opticflow_result_t::divergence, linear_flow_fit_info::divergence, opticflow_t::fast9_adaptive, fast9_detect(), opticflow_t::fast9_min_distance, opticflow_t::fast9_threshold, opticflow_result_t::flow_der_x, opticflow_result_t::flow_der_y, opticflow_result_t::flow_x, flow_t::flow_x, opticflow_result_t::flow_y, flow_t::flow_y, opticflow_result_t::fps, get_size_divergence(), opticflow_t::got_first_img, image_t::h, image_copy(), image_show_flow(), image_show_points(), image_switch(), image_to_grayscale(), opticflow_t::img_gray, LINEAR_FIT, opticflow_t::max_iterations, opticflow_t::max_track_corners, opticflow_result_t::noise_measurement, OPTICFLOW_FOV_H, OPTICFLOW_FOV_W, OPTICFLOW_FX, OPTICFLOW_FY, opticFlowLK(), opticflow_state_t::phi, opticflow_t::prev_img_gray, opticflow_t::prev_phi, opticflow_t::prev_theta, opticflow_t::prev_timestamp, SIZE_DIV, opticflow_t::subpixel_factor, linear_flow_fit_info::surface_roughness, opticflow_result_t::surface_roughness, opticflow_state_t::theta, opticflow_t::threshold_vec, timeval_diff(), opticflow_result_t::tracked_cnt, TRUE, image_t::ts, opticflow_result_t::vel_x, opticflow_result_t::vel_y, image_t::w, and opticflow_t::window_size.

Referenced by opticflow_module_calc().

Here is the call graph for this function:

Here is the caller graph for this function:

void opticflow_calc_init	(	struct opticflow_t *	opticflow,
		uint16_t	w,
		uint16_t	h
	)

Initialize the opticflow calculator.

Parameters

[out]	*opticflow	The new optical flow calculator
[in]	*w	The image width
[in]	*h	The image height

Definition at line 125 of file opticflow_calculator.c.

References FALSE, image_create(), IMAGE_GRAYSCALE, OPTICFLOW_FAST9_ADAPTIVE, OPTICFLOW_FAST9_MIN_DISTANCE, OPTICFLOW_FAST9_THRESHOLD, OPTICFLOW_MAX_ITERATIONS, OPTICFLOW_MAX_TRACK_CORNERS, OPTICFLOW_SUBPIXEL_FACTOR, OPTICFLOW_THRESHOLD_VEC, and OPTICFLOW_WINDOW_SIZE.

Referenced by opticflow_module_init().

Here is the call graph for this function:

Here is the caller graph for this function:

static uint32_t timeval_diff ( struct timeval *  starttime, struct timeval *  finishtime  )

static

Calculate the difference from start till finish.

Parameters

[in]	*starttime	The start time to calculate the difference from
[in]	*finishtime	The finish time to calculate the difference from

Returns

The difference in milliseconds

Definition at line 316 of file opticflow_calculator.c.

Referenced by opticflow_calc_frame().

Here is the caller graph for this function: