notes_2020_11_27_7am.txt

notes_2020_11_27_7am.txt

function ContinuousMovements(tables, imageData, 
%
% This algorithm tries to construct a long-range trajectory by inspecting
% the (relatively short) movement vectors obtained from multiple runs of T3 
% (three-image trajectory).

% ======
% (REMARK) Keep a blank line between the HELP section and DETAIL section.
%
% The algorithm used here are simple. Here is a brief description.
%
% (1) Firstly, stationary content is ignored.
% (1.1) Within any T3, if content hasn't moved at all, 
%       such content is ignored.
%
% (2) Secondly, content receiving too few votes are ignored.
% (2.1) The threshold can be configured.
% (2.2) Two kinds of thresholds are used.
% (2.2.1) As a percentage of total samples
% (2.2.2) As a percentage of occupied grid cells
%
% (3) For two adjacent T3 runs, namely FirstRun and SecondRun,
% ... let FirstRun.ImageKeys = (Img1, Img2, Img3)
% ... let SecondRun.ImageKeys = (Img2, Img3, Img4)
% ... let FirstRun.Movements = mv123a, mv123b
% ... let SecondRun.Movements = mv234c, mv234d
% ...
% (3.1) If it is the case that the TAIL of mv123b matches ...
% ... the HEAD of mv234c, they are said to be connected.
% ...
% (3.2) Example with real numbers
% ... mv123a ...          -1           0        -114           0       18382
% ... mv123b ...           0           0           0           0        1826
% ...
% ... mv234c ...        -114           0        -217           0       10697
% ... mv234d ...           0           0           0           0        1698
% ...
% ... mv345e ...        -217           0         -68           0       11416
% ... mv345f ...           0           0           0           0        1601
% ... 
% ... In this example, "mv123a", "mv234c", "mv345e" are connected, because
% ... [-114, 0], [-217, 0] are common prefix/suffix between adjacent pairs
% ... of trajectories.
%
% (4) However, the following situation can lead to a dead-end.
% ...
% (4.1) A trajectory begins with a non-zero movement but ends with a zero
% ... movement (vanishes).
% ...
% (4.2) Example with real numbers
% ... mv456g ...         -68           0           0           0       16737
% ... mv456h ...           0           0           0           0        1651
% ...
% (4.3) When a dead-end is encountered, the T3 (three-image trajectory)
% ... approach has failed. This function will work around the situation by 
% ... invoking ClassifyMovements using additional images (not necessarily 
% ... limited to three) until a continuously non-zero movement vector 
% ... is found.
%
% ======