3.5. Reduction Parameters

The reduction program is located here: ./bin/fmdt-reduce.

The following table summarizes the available parameters:

Argument	Type	Details
--vid-in-path	STRING	See Section 3.5.1.
--vid-in-start	INTEGER	See Section 3.5.2.
--vid-in-stop	INTEGER	See Section 3.5.3.
--vid-in-threads	INTEGER	See Section 3.5.4.
--red-op	STRING	See Section 3.5.5.
--trk-path	STRING	See Section 3.5.6.
--trk-id	BOOLEAN	See Section 3.5.7.
--trk-nat-num	BOOLEAN	See Section 3.5.8.
--trk-only-meteor	BOOLEAN	See Section 3.5.9.
--gt-path	STRING	See Section 3.5.10.
--fra-out-path	STRING	See Section 3.5.11.
--stats	BOOLEAN	See Section 3.5.12.
--stats-histo	BOOLEAN	See Section 3.5.13.

3.5.1. --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).

3.5.2. --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.

3.5.3. --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.

3.5.4. --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.

3.5.5. --red-op

Type

STRING

Default

NONE

Example

--red-op MAX

Set the reduction operation. Supported values are:

• NONE: Does not perform any reduction

• MAX: Performs \(\max(i)\) per pixel \(i\)

• MIN: Performs \(\min(i)\) per pixel \(i\)

• MAX-MIN: Performs \(\max(i)-\min(i)\) per pixel \(i\)

3.5.6. --trk-path

Deprecated

--in-tracks

Type

STRING

Default

[empty]

Example

--trk-path tracks.txt

The tracks file corresponding to the input video (generated from fmdt-detect). See Section 3.1.1 for the description of the expected text input format.

3.5.7. --trk-id

Deprecated

--show-id

Type

BOOLEAN

Example

--trk-id

Show the object ids on the output video and frames. Requires to link with OpenCV library (-DFMDT_OPENCV_LINK CMake option, see Section 2.2.1).

3.5.8. --trk-nat-num

Deprecated

--show-id

Type

BOOLEAN

Example

--trk-nat-num

Natural numbering of the object ids, work only if --trk-id is set.

3.5.9. --trk-only-meteor

Deprecated

--only-meteor

Type

BOOLEAN

Example

--trk-only-meteor

Show only meteors.

3.5.10. --gt-path

Deprecated

--in-gt

Type

STRING

Default

[empty]

Example

--gt-path gt.txt

File containing the ground truth. Ground truth file gives objects positions over time. Here is the expected text format of a line:

{otype} {fbeg} {xbeg} {ybeg} {fend} {xend} {yend}

The tracks file corresponding to the input video (generated from fmdt-detect). See Section 3.1.1 for the description of the expected text input format.

3.5.11. --fra-out-path

Deprecated

--out-frame

Type

STRING

Default

[empty]

Example

--fra-out-path red.png

Path of the output frame.

3.5.12. --stats

Type

BOOLEAN

Example

--stats

Display some statistics about the pixels in the video sequence.

# Pixel Statistics:
# -----------------
#  * frames_cnt   = {fra_cnt}
#  * pix_min      = {px_min}
#  * pix_max      = {px_max}
#  * pix_sum      = {px_sum}
#  * pix_cnt      = {px_cnt}
#  * pix_mean     = {px_mean}
#  * pix_variance = {px_var}
#  * pix_std_dev  = {px_sd}

• {fra_cnt}: The number of parsed frames in the video sequence

• {px_min}: The minimum pixel intensity in the video sequence (\(\min_{px}\))

• {px_max}: The maximum pixel intensity in the video sequence (\(\max_{px}\))

• {px_sum}: The sum of pixel intensities in the video sequence

• {px_cnt}: The total number of pixels in the whole video sequence

• {px_mean}: The mean pixel intensity in the whole video sequence (\(\bar{px}\))

• {px_var}: The pixel intensity variance \(Var_{px}\) (computed according to the Welford’s online algorithm)

• {px_sd}: The pixel intensity standard deviation (\(\sigma_{px} = \sqrt{Var_{px}}\))

3.5.13. --stats-histo

Type

BOOLEAN

Example

--stats-histo

Print pixels histogram on the standard output as follow:

0 9
1 3
2 2
3 5
4 5
5 5
6 5
7 8
8 3
9 11
...
254 52
255 853

Each line corresponds to one pixel intensity. The fist value of the line is the considered pixel intensity and the second one is its occurrences.

Note

--stats-histo automatically sets the --stats parameter.

Note

Can easily be printed in the console with the help of gnuplot:

./bin/fmdt-reduce --vid-in-path [...] --stats-histo | \
    gnuplot -e \
    "set terminal dumb size 100, 30; set autoscale; set xrange [0:255]; set title 'pixel histogram';
    set ylabel 'count'; set xlabel 'pixel value'; plot '-'  with lines notitle";