From e2d2414c3984f6627c3398e0b08147ceae7eac0f Mon Sep 17 00:00:00 2001
From: Leonardo Robol <leo@robol.it>
Date: Wed, 3 Mar 2010 08:41:04 +0100
Subject: [PATCH] =?UTF-8?q?Aggiunte=20alcune=20FilterBanks=20di=20base=20(?=
 =?UTF-8?q?che=20per=C3=B2=20ancora=20mi=20danno=20problemi)=20e=20un=20te?=
 =?UTF-8?q?ntativo=20di=20indovinare=20la=20lunghezza=20della=20filter=20b?=
 =?UTF-8?q?ank=20dalla=20lunghezza=20del=20filtro=20lowpass=20che=20le=20v?=
 =?UTF-8?q?iene=20assegnato.?=
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---
 Filtering/Filtering.py | 64 ++++++++++++++++++++++++++++++++++++++++++++++----
 Filtering/Splitting.py |  5 +++-
 2 files changed, 63 insertions(+), 6 deletions(-)

diff --git a/Filtering/Filtering.py b/Filtering/Filtering.py
index bf939be..705de28 100644
--- a/Filtering/Filtering.py
+++ b/Filtering/Filtering.py
@@ -2,7 +2,7 @@
 # -*- coding: utf-8 -*-
 #
 
-from numpy import array, zeros, convolve, dot, roll
+from numpy import array, zeros, convolve, dot, roll, sqrt
 
 class AbstractFilter():
 
@@ -29,14 +29,14 @@ class FIR(AbstractFilter):
                          samples, 'same')
 
 
-    def GetResponseFunction(self):
+    def GetResponse(self):
         """
         Obtain the vector of coefficients.
         """
         return self.coefficients
 
     def __mul__(self, other):
-        return FIR(convolve(self.coefficients, other.GetResponseFunction()))
+        return FIR(convolve(self.coefficients, other.GetResponse()))
 
             
 
@@ -108,6 +108,10 @@ class FilterBank():
         """
         self.lowPassFilter = lowpass
 
+        # Sembra che la lunghezza del filtro debba essere
+        # la metà del filtro lowpass, arrotondata per eccesso
+        self.SetLength ( (len(lowpass) + 1)/2 )
+
     def SetHighPassFilter(self, highpass):
         """
         Set the High pass filter. It is usually
@@ -184,5 +188,55 @@ class FilterBank():
         
                                  
         
-        
-        
+DaubechiesFilterBank = FilterBank ()
+DaubechiesFilterBank.SetFilterMatrix ( [
+        0.125 * array([ 1 + sqrt(3), 3 + sqrt(3), 3 - sqrt(3), 1 - sqrt(3)]),
+        0.125 * array([ 1 - sqrt(3),-3 + sqrt(3), 3 + sqrt(3),-1 - sqrt(3)]),
+        0.25  * array([ 1 - sqrt(3), 3 - sqrt(3), 3 - sqrt(3), 1 - sqrt(3)]),
+        0.25  * array([-1 - sqrt(3), 3 + sqrt(3),-3 + sqrt(3), 1 - sqrt(3)])
+        ])
+DaubechiesFilterBank.SetLength (3)
+
+HaarFilterBank = FilterBank ()
+HaarFilterBank.SetFilterMatrix ( [
+        [0.5, 0.5],
+        [0.5 ,-0.5],
+        [1 , 1 ],
+        [-1 , 1]
+        ])
+HaarFilterBank.SetLength(1)
+
+LeoFilterBank = FilterBank()
+LeoFilterBank.SetFilterMatrix ( [
+        [0.25 , 0.5 , 0.25 ],
+        [0.25 , -0.5, 0.25] ,
+        [0.5 , 1, 0.5],
+        [0.5, -1, 0.5]
+        ])
+LeoFilterBank.SetLength(3)
+
+StrangFilterBank = FilterBank ()
+StrangFilterBank.SetFilterMatrix ( [
+        0.125 * array([-1,2,6,2,-1]),
+        0.25 * array([1,-2,1]),
+        0.5 * array([1,2,1]),
+        0.25 * array([1,2,-6,2,1])
+        ])
+StrangFilterBank.SetLength(3)
+
+def PRCheck(f):
+
+    a = (f.lowPassFilter * f.lowPassInverseFilter).GetResponse ()
+    b = (f.highPassFilter*f.highPassInverseFilter).GetResponse ()
+    c = (f.highPassFilter*f.lowPassFilter).GetResponse ()
+    return a, b, c
+
+
+h0 = StrangFilterBank.lowPassFilter
+h1 = StrangFilterBank.highPassFilter
+f0 = StrangFilterBank.lowPassInverseFilter
+f1 = StrangFilterBank.highPassInverseFilter
+
+
+
+    
diff --git a/Filtering/Splitting.py b/Filtering/Splitting.py
index 4d10bf5..e55f28d 100644
--- a/Filtering/Splitting.py
+++ b/Filtering/Splitting.py
@@ -21,7 +21,10 @@ class SplittingExample():
 
         filterBank = Filtering.FilterBank ()
         filterBank.SetFilterMatrix ([h0,h1,f0,f1])
-        filterBank.SetDepth (4)
+        filterBank.SetDepth (3)
+
+        # filterBank = Filtering.StrangFilterBank
+        # filterBank.SetDepth(2)
         
         samples = self.LoadSamples ("sunny.pcm")
         wavelets = filterBank.Split (samples)
-- 
2.1.4