Commit 6dbb4aa6 authored by Richard Torenvliet's avatar Richard Torenvliet

Local Binary patterns implementation part

parent f3794d0a
......@@ -285,7 +285,27 @@ the license plate is also available in de XML file, so this is parsed from that
as well.
\subsection{Creating Local Binary Patterns and feature vector}
Every pixel is a center pixel and it is also a value to evaluate but not at the
same time. Every pixel is evaluated as shown in the explanation
of the LBP algorithm. The 8 neighbours around that pixel are evaluated, of course
this area can be bigger, but looking at the closes neighbours can give us more
information about the patterns of a character than looking at neighbours
further away. This form is the generic form of LBP, no interpolation is needed
the pixels adressed as neighbours are indeed pixels.
Take an example where the
full square can be evaluated, there are cases where the neighbours are out of
bounds. The first to be checked is the pixel in the left
bottom corner in the square 3 x 3, with coordinate $(x - 1, y - 1)$ with $g_c$
as center pixel that has coordinates $(x, y)$. If the grayscale value of the
neighbour in the left corner is greater than the grayscale
value of the center pixel than return true. Bitshift the first bit with 7. The
outcome is now 1000000. The second neighbour will be bitshifted with 6, and so
on. Until we are at 0. The result is a binary pattern of the local point just
evaluated.
Now only the edge pixels are a problem, but a simpel check if the location of
the neighbour is still in the image can resolve this. We simply return false if
it is.
\subsection{Classification}
......
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