Sheikh Qaisar Ayub Ayub , Sulma Rashid
Advanced topic in Image Processing
Pruning By Qaisar Ayub
[email protected]
Pruning What ? A post processing Operation on images Thinning and skeltonization algorithms tends to leave the parasitic components Parasitic Components
Pruning
Pruning Problem Our task is to recognize the hand written characters
Solution Find the skeleton of each character During the process of skeleton some of the parasitic components associated in each character These parasitic components derived due to the non uniformalities in the strokes composing the character
Pruning Parasitic
Observe Parasitic Components
Q
Pruning Achievements 1.
What What is pr prun unin ing g
2.
Para Parasi siti tic c Comp Compon onen ents ts
Pruning To understand the pruning algorithm we take an example of recognizing the handwritten h andwritten character µa¶
After applying the skeltionization algorithm we get the following structure
Pruning This is what we are interested to remove
Pruning Algorithm Step-01 Suppress the parasitic components by eliminating the end points By applying the thinning algorithm on the image we can get endpoints Mathematically the thinning algorithm can be written as X1 = A
{B}
Pruning Algorithm Step-01 X1 = A
{B}
B := Structuring element { } := Represent the iteration A := Input Image := Hit or Miss Translation
Pruning Algorithm Step-01 X1 = A
{B}
Structuring element {B} = B1 B2 B3 B4 B5 B6 B7 B8 B1 B2 B3 B4
Pruning Algorithm Step-01 X1 = A
{B}
Structuring element {B} = B5 B6 B7 B8 B5
:=
B6:= B7:= B8:=
Pruning
Pruning
Pruning
Pruning
Pruning
Pruning
Pruning
Pruning
Pruning
Pruning
Pruning
Pruning
Pruning
Pruning
Pruning
Pruning
Pruning
Pruning
Pruning No match found Row 01
Pruning
Pruning
Pruning
Pruning
Pruning
Pruning
Pruning
Pruning
Pruning
Pruning
Pruning
Pruning
Pruning
Pruning
Pruning
Pruning
Pruning
Pruning
Pruning
Pruning
Pruning
Pruning
Pruning
Pruning
Pruning
Pruning
Pruning
Pruning
Pruning
Pruning
Pruning
Pruning
Pruning
Pruning
Pruning
Pruning
Pruning
Pruning
Pruning
Pruning
Pruning
Pruning
Pruning
Pruning
Pruning
Pruning
Pruning
Pruning
Pruning
Pruning
Pruning
Pruning
Pruning
Pruning
Pruning
Pruning
Pruning
Pruning
Pruning
Pruning
Pruning
Pruning
Pruning
Pruning
Pruning
Pruning
Pruning
Pruning
Pruning
Pruning
Pruning
Pruning
Pruning
Pruning
Pruning
Pruning
Pruning
Pruning
Pruning
Pruning
Pruning
Pruning
Pruning
Pruning
Pruning
Pruning
Pruning
Pruning
Pruning
Pruning
Pruning
Pruning
Pruning
Pruning
Pruning
Pruning
Pruning
Pruning
Pruning
Pruning
Pruning
Pruning
Pruning
Pruning
Pruning
Pruning
Pruning
Pruning
Pruning
Pruning
Pruning
Pruning
Pruning
Pruning
Pruning
Pruning
Pruning
Pruning
Pruning
Pruning
Pruning
Pruning
Pruning
Pruning
Pruning
Pruning
Pruning
Pruning
Pruning
Pruning
Pruning
X1=
After applying thinning 3 times we get X1
Pruning Achievements End Point Removing process has been completed
Pruning Algorithm Step-02 Restore the character to its original Form by removing parasitic branches Solution Form a set X2 by which contains all end point in X1 Following equation is used to achieve this
Pruning Algorithm Step-02
X1
X1
B1
B2
Pruning Algorithm Step-02
X1
X1
B3
B4
Pruning Algorithm Step-02
X1
X1
B5
B6
Pruning Algorithm Step-02
X1
X1
B7
B8
Pruning
X2=
Pruning Achievements
End point have been found from X1
Pruning Algorithm Step-03
X2=
H= Structuring Element
Pruning
Pruning
Pruning
Pruning
Pruning
Pruning
Pruning
Pruning
Pruning
Pruning
Pruning
Pruning
Pruning
Pruning Achievements
Dilation process at end point have been completed
Pruning Algorithm Step-03 Continue«
A
Pruning
X3 =
A
Pruning Achievements
Pruning Algorithm Step-04 X4 = X1 U X3
Pruning Algorithm Step-04 X4 = X1 U X3
Thanks
