# HG changeset patch
# User Laman
# Date 2019-02-07 11:27:25
# Node ID 6d4447a2e0509128d3567db00bff34d823890f71
# Parent  ffa9f7f12374f95efd6869191cd62c4d93c0fffb

filtering close points, detecting dominant angles

diff --git a/exp/hough.py b/exp/hough.py
--- a/exp/hough.py
+++ b/exp/hough.py
@@ -1,5 +1,7 @@
+import sys
+sys.path.append("../src")
+
 import os
-import sys
 import math
 from datetime import datetime
 import logging as log
@@ -8,6 +10,7 @@ import numpy as np
 import cv2 as cv
 
 from annotations import DataFile,computeBoundingBox
+from analyzer.epoint import EPoint
 
 
 class HoughTransform:
@@ -23,7 +26,12 @@ class HoughTransform:
 		maxVal=self._acc.max()
 		arr=np.expand_dims(np.uint8(255*self._acc//maxVal),axis=2)
 		img=np.concatenate((arr,arr,arr),axis=2)
-		log.debug(sorted(list(findPeaks(self._acc)),key=lambda rc: self._acc[rc],reverse=True)[:2*19])
+		peaks=sorted(list(findPeaks(self._acc)),key=lambda rc: self._acc[rc],reverse=True)[:2*19]
+		peaks=self._filterClose(peaks)
+		peaks=[(alpha,d) if alpha<180 else (alpha-180,-d) for (alpha,d) in peaks]
+		peaks.sort(key=lambda rc: rc[0])
+		log.debug("detected peaks: %s",peaks)
+		self._detectDominantAngles(peaks)
 		show(img,"Hough transform accumulator")
 
 	def update(self,img,weight=1):
@@ -43,8 +51,44 @@ class HoughTransform:
 		d=dx*math.cos(alphaRad)+dy*math.sin(alphaRad)
 		return int(d)
 
+	def _filterClose(self,peaks): # a naive implementation
+		minDist=10
+		center=EPoint(*self._center)
+		res=[]
+		for (alphaDeg,d) in peaks:
+			alphaRad=alphaDeg*math.pi/180
+			point=EPoint.fromPolar((alphaRad,d),center)
+			ctrl=True
+			for (betaDeg,e) in peaks:
+				betaRad=betaDeg*math.pi/180
+				point_=EPoint.fromPolar((betaRad,e),center)
+				if point.dist(point_)<minDist and self._acc[(alphaDeg,d)]<self._acc[(betaDeg,e)]:
+					ctrl=False
+			if ctrl: res.append((alphaDeg,d))
+		return res
 
-def findPeaks(arr2d): # naive implementation
+	def _detectDominantAngles(self,peaks):
+		angles=[alpha for (alpha,d) in peaks]
+		n=len(angles)
+		bandwidth=30
+		k1=0
+		k2=1
+		histogram=[]
+		while k1<n:
+			while (k2<n and angles[k1]+bandwidth>angles[k2]) or (k2>=n and angles[k1]+bandwidth>angles[k2%n]+180):
+				k2+=1
+			histogram.append((angles[k1],k2-k1))
+			k1+=1
+		log.debug("angles histogram: %s",histogram)
+		dominantAngles=sorted(histogram,key=lambda xy: xy[1],reverse=True)
+		alpha=dominantAngles[0]
+		dominantAngles=[beta for beta in dominantAngles if 165>abs(alpha[0]-beta[0])>15]
+		beta=dominantAngles[0]
+		log.debug("dominant angles: %s, %s",alpha,beta)
+		return (alpha[0],beta[0])
+
+
+def findPeaks(arr2d): # a naive implementation
 	(h,w)=arr2d.shape
 	neighbours=[(-1,-1),(-1,0),(-1,1),(0,-1),(0,1),(1,-1),(1,0),(1,1)]
 	for r in range(h):