3.1. Detection Parameters¶

The meteors detection chain is located here: ./bin/fmdt-detect.

The following table summarizes the available parameters:

Argument	Type	Details
`--vid-in-path`	STRING	See Section 3.1.2.
`--vid-in-start`	INTEGER	See Section 3.1.3.
`--vid-in-stop`	INTEGER	See Section 3.1.4.
`--vid-in-skip`	INTEGER	See Section 3.1.5.
`--vid-in-buff`	BOOLEAN	See Section 3.1.6.
`--vid-in-loop`	INTEGER	See Section 3.1.7.
`--vid-in-threads`	INTEGER	See Section 3.1.8.
`--ccl-hyst-lo`	INTEGER	See Section 3.1.9.
`--ccl-hyst-hi`	INTEGER	See Section 3.1.10.
`--ccl-fra-path`	STRING	See Section 3.1.11.
`--ccl-fra-id`	BOOLEAN	See Section 3.1.12.
`--mrp-s-min`	INTEGER	See Section 3.1.13.
`--mrp-s-max`	INTEGER	See Section 3.1.14.
`--knn-k`	INTEGER	See Section 3.1.15.
`--knn-d`	INTEGER	See Section 3.1.16.
`--knn-s`	FLOAT	See Section 3.1.17.
`--trk-ext-d`	INTEGER	See Section 3.1.18.
`--trk-ext-o`	INTEGER	See Section 3.1.19.
`--trk-angle`	FLOAT	See Section 3.1.20.
`--trk-star-min`	INTEGER	See Section 3.1.21.
`--trk-meteor-min`	INTEGER	See Section 3.1.22.
`--trk-meteor-max`	INTEGER	See Section 3.1.23.
`--trk-ddev`	FLOAT	See Section 3.1.24.
`--trk-all`	BOOLEAN	See Section 3.1.25.
`--trk-bb-path`	STRING	See Section 3.1.26.
`--trk-mag-path`	STRING	See Section 3.1.27.
`--log-path`	STRING	See Section 3.1.28.

3.1.1. Standard Output¶

fmdt-detect outputs a list of tracks. The tracks represent the detected objects in the video sequence. Here is the template of the output text:

# -------||---------------------------||---------------------------||---------
#  Track ||           Begin           ||            End            ||  Object
# -------||---------------------------||---------------------------||---------
# -------||---------|--------|--------||---------|--------|--------||---------
#     Id || Frame # |      x |      y || Frame # |      x |      y ||    Type
# -------||---------|--------|--------||---------|--------|--------||---------
   {tid} ||  {fbeg} | {xbeg} | {ybeg} ||  {fend} | {xend} | {yend} || {otype}

{tid}: a positive integer (start from 1) value representing a unique track identifier,
{fbeg}: a positive integer value representing the first frame in the video sequence when the track is detected,
{xbeg}: a positive real value of the x-axis coordinate (beginning of the track),
{ybeg}: a positive real value of the y-axis coordinate (beginning of the track),
{fend}: a positive integer value representing the last frame in the video sequence when the track is detected,
{xend}: a positive real value of the x-axis coordinate (end of the track),
{yend}: a positive real value of the y-axis coordinate (end of the track),
{otype}: a string of the object type, can be: meteor, star or noise.

3.1.2. `--vid-in-path`¶

Deprecated

--in-video

Type

STRING

Default

[empty]

Example

--vid-in-path ~/Videos/meteors.mp4

Input video path (supports also a path to a sequence of images path/basename_%05d.jpg).

3.1.3. `--vid-in-start`¶

Deprecated

--fra-start

Type

INTEGER

Default

0

Example

--vid-in-start 12

First frame id (included) to start the detection in the video sequence.

3.1.4. `--vid-in-stop`¶

Deprecated

--fra-end

Type

INTEGER

Default

0

Example

--vid-in-stop 42

Last frame id (included) to stop the detection in the video sequence. If set to 0, read entire video.

3.1.5. `--vid-in-skip`¶

Deprecated

--fra-skip

Type

INTEGER

Default

0

Example

--vid-in-skip 1

Number of frames to skip.

3.1.6. `--vid-in-buff`¶

Deprecated

--video-buff

Type

BOOLEAN

Example

--vid-in-buff

Bufferize all the video in global memory before executing the chain.

3.1.7. `--vid-in-loop`¶

Deprecated

--video-loop

Type

INTEGER

Default

1

Example

--vid-in-loop 10

Number of times the video is read in loop.

3.1.8. `--vid-in-threads`¶

Deprecated

--ffmpeg-threads

Type

INTEGER

Default

0

Example

--vid-in-threads 1

Select the number of threads to use to decode video input (in ffmpeg). If set to 0, ffmpeg chooses the number of threads automatically.

3.1.9. `--ccl-hyst-lo`¶

Deprecated

--light-min

Type

INTEGER

Default

55

Example

--ccl-hyst-lo 100

Minimum light intensity for hysteresis threshold (grayscale \([0;255]\)).

3.1.10. `--ccl-hyst-hi`¶

Deprecated

--light-max

Type

INTEGER

Default

80

Example

--ccl-hyst-hi 140

Maximum light intensity for hysteresis threshold (grayscale \([0;255]\)).

3.1.11. `--ccl-fra-path`¶

Deprecated

--out-frames

Type

STRING

Default

[empty]

Example

--ccl-fra-path ccl_fra/%05d.png

Path of the files for CC debug (path/cc_%05d.png).

3.1.12. `--ccl-fra-id`¶

Deprecated

--show-id

Type

BOOLEAN

Example

--ccl-fra-id

Show the RoI/CC ids on the output frames (to combine with --ccl-fra-path parameter). Requires to link with OpenCV library (-DFMDT_OPENCV_LINK CMake option, see Section 2.2.1).

3.1.13. `--mrp-s-min`¶

Deprecated

--surface-min

Type

INTEGER

Default

3

Example

--mrp-s-min 5

Minimum surface of the CCs in pixels.

3.1.14. `--mrp-s-max`¶

Deprecated

--surface-max

Type

INTEGER

Default

1000

Example

--mrp-s-max 50

Maximum surface of the CCs in pixels.

3.1.15. `--knn-k`¶

Deprecated

-k

Type

INTEGER

Default

3

Example

--knn-k 5

Maximum number of neighbors considered in the k-NN algorithm.

3.1.16. `--knn-d`¶

Deprecated

--max-dist

Type

INTEGER

Default

10

Example

--knn-d 25

Maximum distance in pixels between two images (k-NN algorithm).

3.1.17. `--knn-s`¶

Deprecated

--min-ratio-s

Type

FLOAT

Default

0.125

Example

--knn-s 0.0

Minimum surface ratio to match two CCs in k-NN (0 matches alls, 1 matches nothing). This parameter is also used for extrapolation in the tracking.

3.1.18. `--trk-ext-d`¶

Deprecated

--r-extrapol

Type

INTEGER

Default

10

Example

--trk-ext-d 25

Search radius in pixels for CC extrapolation (piece-wise tracking).

3.1.19. `--trk-ext-o`¶

Deprecated

--extrapol-orde

Type

INTEGER

Default

3

Example

--trk-ext-o 1

Maximum number of frames to extrapolate for lost objects (linear extrapolation).

3.1.20. `--trk-angle`¶

Deprecated

--angle-max

Type

FLOAT

Default

20.0

Example

--trk-angle 35.0

Tracking max angle between two meteors at \(t-1\) and \(t\) (in degree).

3.1.21. `--trk-star-min`¶

Deprecated

--fra-star-min

Type

INTEGER

Default

15

Example

--trk-star-min 5

Minimum number of frames required to track a star.

3.1.22. `--trk-meteor-min`¶

Deprecated

--fra-meteor-min

Type

INTEGER

Default

3

Example

--trk-meteor-min 5

Minimum number of frames required to track a meteor.

3.1.23. `--trk-meteor-max`¶

Deprecated

--fra-meteor-max

Type

INTEGER

Default

100

Example

--trk-meteor-max 50

Maximum number of frames required to track a meteor.

3.1.24. `--trk-ddev`¶

Deprecated

--diff-dev

Type

FLOAT

Default

4.0

Example

--trk-ddev 5.5

Multiplication factor of the standard deviation (CC error has to be higher than \(ddev \times stddev\) to be considered in movement).

3.1.25. `--trk-all`¶

Deprecated

--track-all

Type

BOOLEAN

Example

--trk-all

By default the program only tracks meteor object type. If --trk-all is set, all object types are tracked (meteor, star or noise).

This parameter is used in the _tracking_perform() function.

3.1.26. `--trk-bb-path`¶

Deprecated

--out-bb

Type

STRING

Default

[empty]

Example

--trk-bb-path bb.txt

Path to the bounding boxes file required by fmdt-visu to draw detection rectangles. Each bounding box defines the area of an object, frame by frame.

Here is the corresponding line format:

{frame_id} {x_radius} {y_radius} {center_x} {center_y} {track_id} {is_extrapolated}

Each line corresponds to a frame and to an object, each value is separated by a space character.

3.1.27. `--trk-mag-path`¶

Deprecated

--out-mag

Type

STRING

Default

[empty]

Example

--trk-mag-path mag.txt

Path to the output file containing magnitudes of the tracked objects. Each line corresponds to a track/object and here is the corresponding line format:

{tid} {otype} {mag1} {mag2} {...} {magn}

{mag1} is the first magnitude value of the track/object of {tid} id. {mag2} is the second magnitude value (in the second frame where the object has been tracked). And so on, until the last magnitude value {magn}. Note that sometime the magnitude value can be 0, it means that the object has been extrapolated on this frame, thus the magnitude cannot be computed.

3.1.28. `--log-path`¶

Deprecated

--out-stats

Type

STRING

Default

[empty]

Example

--log-path detect_logs/

Path of the output statistics, only required for debugging purpose.

Warning

This section targets advanced users, some knowledge about the implemented algorithms may be required!! You have been warned ;-).

fmdt-detect comes with the --log-path option to help to understand what is happening during the execution. This option enables to log internal statistics of the different algorithms used to detect meteors.

The folder contains multiple files, one per frame. For instance, the file name for the frame n°12 is: 00012.txt. Each file contains 5 different tables:

Table 1: list of RoIs at \(t - 1\) (result of the CCL/CCA + hysteresis algorithm at \(t - 1\)),
Table 2: list of RoIs at \(t\) (result of the CCL/CCA + hysteresis algorithm at \(t\)),
Table 3: list of associations between \(t - 1\) RoIs and \(t\) RoIs (result of the k-NN algorithm) + errors/velocities after motion estimation,
Table 4: motion estimation statistics between \(t - 1\) and \(t\) frame,
Table 5: list of tracks since the beginning of the execution (final output of the detection chain).

Note

The first log file (usally named 00000.txt) only contains the table 2. This is normal because algorithms starting from k-NN require two consecutive frames to work.

3.1.28.1. Table 1 and table 2: RoIs¶

# ------||----------------||---------------------------||---------------------------||-------------------||-----------||------------
#   RoI ||      Track     ||        Bounding Box       ||   Surface (S in pixels)   ||      Center       || Magnitude || Saturation
# ------||----------------||---------------------------||---------------------------||-------------------||-----------||------------
# ------||------|---------||------|------|------|------||-----|----------|----------||---------|---------||-----------||------------
#    ID ||   ID |    Type || xmin | xmax | ymin | ymax ||   S |       Sx |       Sy ||       x |       y ||        -- ||    Counter
# ------||------|---------||------|------|------|------||-----|----------|----------||---------|---------||-----------||------------
  {rid} || {tid}| {otype} ||{xmin}|{xmax}|{ymin}|{ymax}|| {S} |     {Sx} |     {Sy} ||    {cx} |    {cy} ||     {mag} ||      {sat}

Each line corresponds to one RoI:

{rid}: unique identifier for the current RoI (start from 1),
{tid}: unique identifier of the corresponding track (start from 1), can be, empty if no track is associated to the current RoI,
{otype}: type of the track object (meteor, noise or star), only if there is a track corresponding to this RoI,
{xmin}: minimum \(x\) position of the bounding box,
{xmax}: maximum \(x\) position of the bounding box,
{ymin}: minimum \(y\) position of the bounding box,
{ymax}: maximum \(y\) position of the bounding box,
{S}: surface (area) of the RoI in pixels,
{Sx}: sum of \(x\) properties,
{Sy}: sum of \(y\) properties,
{cx}: \(x\) center of mass,
{cy}: \(y\) center of mass,
{mag}: magnitude of the current RoI (accumulated brightness of the RoI, see the _features_compute_magnitude() function),
{sat}: number of pixels that are saturated in the current RoI (a pixel \(p\) is saturated when its intensity \(I_p = 255\), see the _features_compute_magnitude() function).

3.1.28.2. Table 3: List of associations between RoIs¶

# --------------------||---------------||------------------------||-----------
#         RoI ID      ||    Distance   ||  Error (or velocity)   ||   Motion
# --------------------||---------------||------------------------||-----------
# ----------|---------||--------|------||-------|-------|--------||-----------
#       t-1 |       t || pixels | rank ||    dx |    dy |      e || is moving
# ----------|---------||--------|------||-------|-------|--------||-----------
  {rid_t-1} | {rid_t} || {dist} |  {k} ||  {dx} |  {dy} |    {e} ||      {mov}

Each line corresponds to an association between one RoI at \(t - 1\) and at \(t\):

{rid_t-1}: id of the RoI in the table 1 (in the \(t - 1\) frame),
{rid_t} : id of the RoI in the table 2 (in the \(t\) frame),
{dist}: distance in pixels between the two RoIs,
{rank}: rank in the k-NN algorithm, if 1: it means that this is the closest RoI association, if 2: it means that this is the second closest RoI association, etc.,
{dx}: \(x\) distance between the estimated position (after motion estimation) and the real position (in frame \(t - 1\)),
{dy}: \(y\) distance between the estimated position (after motion estimation) and the real position (in frame \(t - 1\)),
{e}: euclidean distance between the estimated position and the real position,
{mov}: yes if the RoI is moving, no otherwise. The criteria to detect the motion of an RoI is: \(|e - \bar{e^1_t}| > \sigma^1_t\), with \(e\) the error of the current RoI, \(\bar{e^1_t}\) the mean error after the first motion estimation and \(\sigma^1_t\) the standard deviation after the first motion estimation.

If {mov} = yes then, {dx}, {dy} is the velocity vector and {e} is the velocity norm in pixel.

Note

{dx}, {dy}, {e} and {mov} are computed after the second motion estimation.

3.1.28.3. Table 4: Motion Estimation Statistics¶

# ------------------------------------------------------||------------------------------------------------------
#   First motion estimation (with all associated RoIs)  ||    Second motion estimation (exclude moving RoIs)
# ------------------------------------------------------||------------------------------------------------------
# ----------|----------|----------|----------|----------||----------|----------|----------|----------|----------
#     theta |       tx |       ty | mean err |  std dev ||    theta |       tx |       ty | mean err |  std dev
# ----------|----------|----------|----------|----------||----------|----------|----------|----------|----------
   {theta1} |    {tx1} |    {ty1} |{mean_er1}|{std_dev1}|| {theta2} |    {tx2} |    {ty2} |{mean_er2}|{std_dev2}

There is only one line in this table. It represents the motion estimation between frame \(t - 1\) and frame \(t\):

{theta}: the estimated rotation angle between frame \(t\) and frame \(t - 1\),
{tx} and {ty}: the estimated translation vector from frame \(t\) to frame \(t - 1\),
{mean_er}: the mean error of the associated RoIs,
{std_dev}: the standard deviation of the associated RoI errors.

The first estimation considers all the associated RoIs while the second estimation excludes the associated RoIs in movement. To be considered in movement, an RoI has to verify the following condition: \(|e - \bar{e^1_t}| > \sigma^1_t\), with \(e\) the error of the current RoI, \(\bar{e^1_t}\) the mean error after the first motion estimation and \(\sigma^1_t\) the standard deviation after the first motion estimation.

3.1.28.4. Table 5: List of Tracks¶

# -------||---------------------------||---------------------------||---------||-------------------
#  Track ||           Begin           ||            End            ||  Object || Reason of changed
# -------||---------------------------||---------------------------||---------||    state (from
# -------||---------|--------|--------||---------|--------|--------||---------||  meteor to noise
#     Id || Frame # |      x |      y || Frame # |      x |      y ||    Type ||    object only)
# -------||---------|--------|--------||---------|--------|--------||---------||-------------------
   {tid} ||  {fbeg} | {xbeg} | {ybeg} ||  {fend} | {xend} | {yend} || {otype} ||          {reason}

Most of the columns of this table have been described in the Standard Output section, here we focus only on extra columns:

{reason}: reason of the classification from meteor to noise.

3.1. Detection Parameters¶

3.1.1. Standard Output¶

3.1.2. --vid-in-path¶

3.1.3. --vid-in-start¶

3.1.4. --vid-in-stop¶

3.1.5. --vid-in-skip¶

3.1.6. --vid-in-buff¶

3.1.7. --vid-in-loop¶

3.1.8. --vid-in-threads¶

3.1.9. --ccl-hyst-lo¶

3.1.10. --ccl-hyst-hi¶

3.1.11. --ccl-fra-path¶

3.1.12. --ccl-fra-id¶

3.1.13. --mrp-s-min¶

3.1.14. --mrp-s-max¶

3.1.15. --knn-k¶

3.1.16. --knn-d¶

3.1.17. --knn-s¶

3.1.18. --trk-ext-d¶

3.1.19. --trk-ext-o¶

3.1.20. --trk-angle¶

3.1.21. --trk-star-min¶

3.1.22. --trk-meteor-min¶

3.1.23. --trk-meteor-max¶

3.1.24. --trk-ddev¶

3.1.25. --trk-all¶

3.1.26. --trk-bb-path¶

3.1.27. --trk-mag-path¶

3.1.28. --log-path¶