opticflow_calculator.h File Reference

Calculate velocity from optic flow. More...

#include "std.h"
#include "inter_thread_data.h"
#include "lib/vision/image.h"
#include "lib/v4l/v4l2.h"

Include dependency graph for opticflow_calculator.h:

This graph shows which files directly or indirectly include this file:

Go to the source code of this file.

Data Structures
struct	opticflow_t

Functions
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

Calculate velocity from optic flow.

Using images from a vertical camera and IMU sensor data.

Definition in file opticflow_calculator.h.

---

Data Structure Documentation

struct opticflow_t

Definition at line 37 of file opticflow_calculator.h.

Collaboration diagram for opticflow_t:

Data Fields
bool_t	fast9_adaptive	Whether the FAST9 threshold should be adaptive.
uint16_t	fast9_min_distance	Minimum distance in pixels between corners.
uint8_t	fast9_threshold	FAST9 corner detection threshold.
bool_t	got_first_img	If we got a image to work with.
struct image_t	img_gray	Current gray image frame.
uint8_t	max_iterations	The maximum amount of iterations the Lucas Kanade algorithm should do.
uint8_t	max_track_corners	Maximum amount of corners Lucas Kanade should track.
struct image_t	prev_img_gray	Previous gray image frame.
float	prev_phi	Phi from the previous image frame.
float	prev_theta	Theta from the previous image frame.
struct timeval	prev_timestamp	Timestamp of the previous frame, used for FPS calculation.
uint8_t	subpixel_factor	The amount of subpixels per pixel.
uint8_t	threshold_vec	The threshold in x, y subpixels which the algorithm should stop.
uint16_t	window_size	Window size of the Lucas Kanade calculation (needs to be even)

Function Documentation

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: