Started working on reconstruction

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Marius Drechsler 2024-07-19 17:45:34 +02:00
parent ea1d02ce9f
commit 1ac5a9e093
6 changed files with 131 additions and 2 deletions

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@ -172,3 +172,38 @@ Each measurement will be quantized with out quantizer $cal(E)$, returning a tupl
$ K_i = cal(E)(s, m tilde(x_i)) = (k, h)_i $ <eq:smhd_quant>
Performing the operation of @eq:smhd_quant for our whole set of measurements will yield a vector of tuples $bold(K)$.
#pagebreak()
=== Reconstruction
We already demonstrated the basic principle of the reconstruction phase in section @sect:tmhd, more specifically with @fig:tmhd_example_enroll and @fig:tmhd_example_reconstruct, which show the advantage of using more than one quantizer during reconstruction.
We will call our repeated measurement of $tilde(x)$ that is subject to a certain error $tilde(x^*)$.
To perform reconstruction with $tilde(x^*)$, we will first need to find all $s$ quantizers for which we generated the helper data in the previous step.
We have to distinguish two different cases for the value of $s$:
- $s$ is odd
- $s$ is even
==== Even number of metrics
If $s$ is even, we need to move our quantizer $s/2$ times some distance to the right and $s/2$ times some distance to the left.
We can define the ideal position for the quantizer bounds based on its corresponding metric as centered around the center of the related metric.
We can find these new bounds graphically as depicted in @fig:smhd_find_bound_graph. We first determine the x-values of the centers of a metric (here M1, as shown with the arrows). We can then place the quantizer steps with step size $Delta$ (@eq:delta) evenly spaced around these points.
#grid(
columns: (1fr, 0.1fr, 1fr),
[#scale(x: 70%, y: 70%)[
#figure(
include("../graphics/quantizers/s-metric/2_2_find_quantizer.typ"),
caption: [Ideal centers and bounds for the M1 quantizer]
)<fig:smhd_find_bound_graph>]],
[#align(center)[#align(horizon)[#text(25pt)[$arrow.r.double$]]]],
[#scale(x: 70%, y: 70%)[
#figure(
include("../graphics/quantizers/s-metric/2_2_found_quantizer1.typ"),
caption: [Quantizer for the first metric]
)]]
)