$.($Particle Tracking$)$ The next step is to determine how far a bead moved from one time step t to the next t $+$t$.$ For our data, $$t $=0\mathrm{.}5$ seconds per frame. We assume the data is such that each bead moves a relatively small amount, and that two beads do not collide. However, we must account for the possibility that the bead disappears from the frame, either by departing the microscope$$s field of view in the x$-$ or y$-$ direction, or moving out of the microscope$$s depth of focus in the z$-$direction. Thus, for each bead at time t $+$t$,$ we calculate the closest bead at time t $($in Euclidean distance$)$ and identify these two as the same beads. However, if the distance is too large, ie$,$ greater than $($delta$)$ pixels, we assume that one of the beads has either just begun or ended its journey. We record the displacement that each bead travels in the $$t units of time. Implement a program called bead$\_$tracker.py that accepts p $($int$),$ tau $($float$),$ delta $($float$),$ and a sequence of JPEG filenames as command$-$line arguments; identifies the beads in each JPEG image using BlobFinder; and writes to standard output $($one per line, formatted with $4$ decimal places to the right of decimal point$)$ the radial distance that each bead moves from one frame to the next $($assuming it is no more than delta$).$ Note that it is not necessary to explicitly track a bead through a sequence of frames $$ you only need to worry about identifying the same bead in two consecutive frames. Accept command$-$line arguments pixels $($int$),$ tau $($float$),$ and delta $($float$)$ Construct a BlobFinder object for the frame sys$.$argv$[4]$ and from it get a list of beads prevBeads that have at least pixels pixels For each frame starting at sys$.$argv$[5]$:$-$ Construct a BlobFinder object and from it get a list of beads currBeads that have at least pixels pixels$-$ For each bead currBead in currBeads, find a bead prevBead from prevBeads that is no further than delta and is closest to currBead, and if such a bead is found, write its distance $($using format string $\%\mathrm{.}4$f

$)$ to currBead$-$ Write a newline character$-$ Set prevBeads to currBeads