Changeset - 90090fca08f9
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Laman - 6 years ago 2019-02-17 10:44:37

experiment with double Hough transform
1 file changed with 114 insertions and 41 deletions:
exp/hough.py
114
41
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exp/hough.py
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import sys
 
sys.path.append("../src")
 

	
 
import os
 
import math
 
from datetime import datetime
 
import logging as log
 

	
 
import numpy as np
 
import scipy.optimize
 
import cv2 as cv
 

	
 
from annotations import DataFile,computeBoundingBox
 
from geometry import Line
 
from analyzer.epoint import EPoint
 

	
 
DEBUG=True
 

	
 

	
 
class BaseHough:
 
	def __init__(self,width,height):
 
		self._diagLen=int(np.sqrt(height**2+width**2))+1
 
		self._center=(width//2,height//2)
 
		self._acc=np.zeros((180,self._diagLen),dtype=np.int32)
 

	
 
	def update(self,x,y,weight=1):
 
		""":param x: number, 0 <= x < width
 
		:param y: number, 0 <= y < height"""
 
		for alphaDeg in range(0,180):
 
			d=self._computeDist(x,y,alphaDeg)+self._diagLen//2
 
			self._acc[(alphaDeg,d)]+=weight
 

	
 
	def extract(self,n):
 
		shift=self._diagLen//2
 
		peaks=sorted(list(findPeaks(self._acc)),key=lambda rc: self._acc[rc],reverse=True)
 
		peaks=self._filterClose(peaks)[:n]
 
		log.debug("detected peaks: %s",[(alpha,d-shift) for (alpha,d) in peaks])
 

	
 
		img=self._createImg()
 
		img=self._markPeaks(img,self._filterClose(peaks))
 
		self.show(img)
 

	
 
		res=[]
 
		for (alphaDeg,d) in peaks:
 
			alphaRad=alphaDeg*math.pi/180
 
			baseLine=Line(alphaRad,0)
 
			dd=baseLine.distanceTo(EPoint(*self._center)) # to shift d from the center to 0,0
 
			res.append(Line(alphaRad, dd+d-shift))
 
		log.debug("detected lines: %s",res)
 
		return res
 

	
 
	def _computeDist(self,x,y,alphaDeg):
 
		"""Compute the distance of a line with the provided alphaDeg declination and passing the (x,y) point to the image center.
 
		The returned distance might be negative (meaning the angle is in fact alpha+180)."""
 
		alphaRad=alphaDeg*math.pi/180
 
		(x0,y0)=self._center
 
		(dx,dy)=(x-x0,y-y0)
 
		d=dx*math.cos(alphaRad)+dy*math.sin(alphaRad)
 
		return round(d)
 

	
 
	def _filterClose(self,peaks): # a naive implementation
 
		"""Discard points with Euclidean distance on the original image lower than 10.
 
		From such pairs keep only the one with a higher value in the accumulator.
 
		This can delete a series of points. If a-b and b-c are close and a>b>c, only a is kept."""
 
		minDist=13
 
		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 show(self,img=None):
 
		if not DEBUG: return
 
		if img is None: img=self._createImg()
 

	
 
		show(img,"Hough transform accumulator")
 

	
 
	def _createImg(self):
 
		maxVal=self._acc.max()
 
		arr=np.expand_dims(np.uint8(255*self._acc//maxVal),axis=2)
 
		img=np.concatenate((arr,arr,arr),axis=2)
 

	
 
		(h,w)=img.shape[:2]
 

	
 
		for x in range(0,w,4): # y axis
 
			img[h//2,x]=[255,255,255]
 
		for y in range(0,h,4):
 
			img[y,w//2]=[255,255,255]
 

	
 
		return img
 

	
 
	def _markPeaks(self,img,peaks):
 
		colors=[[255,0,0],[255,255,0],[0,255,0],[0,255,255],[0,0,255]]
 
		for (i,(alpha,d)) in enumerate(peaks[:38]):
 
			cv.drawMarker(img,(d,alpha),colors[i//9],cv.MARKER_TILTED_CROSS)
 
		return img
 

	
 

	
 
class HoughTransform:
 
	def __init__(self,img):
 
		self._angleBandwidth=30 # degrees
 

	
 
		(h,w)=img.shape[:2]
 
@@ -30,21 +118,25 @@ class HoughTransform:
 
		allPeaks=sorted(list(findPeaks(self._acc)),key=lambda rc: self._acc[rc],reverse=True)
 
		peaks=allPeaks[:38]
 
		peaks=[(alpha,d-shift) for (alpha,d) in peaks]
 
		peaks=self._filterClose(peaks)
 
		peaks.sort(key=lambda rc: rc[0])
 
		log.debug("detected peaks: %s",peaks)
 
		(alpha,beta)=self._detectDominantAngles(peaks)
 

	
 
		h2=BaseHough(self._diagLen,180+90)
 
		for (alpha,d) in peaks:
 
			h2.update(d+shift,alpha)
 
			if alpha<90:
 
				h2.update(shift-d,alpha+180)
 
		lines=h2.extract(3)
 

	
 
		img=self._createImg()
 
		img=self._markPeaks(img,self._filterClose(allPeaks[:38]))
 
		doublePeaks=peaks+[(alpha+180,-d) for (alpha,d) in peaks]
 
		params=self._computeGridParams([(gamma,d+shift) for (gamma,d) in doublePeaks if alpha<=gamma<=alpha+self._angleBandwidth])
 
		self._drawGridCurve(img,params,0)
 
		params=self._computeGridParams([(gamma,d+shift) for (gamma,d) in doublePeaks if beta<=gamma<=beta+self._angleBandwidth])
 
		self._drawGridCurve(img,params,1)
 

	
 
		for (i,line) in enumerate(lines):
 
			self.drawLine(img,line,i)
 
		self.show(img)
 

	
 
	def update(self,img,weight=1):
 
		start=datetime.now().timestamp()
 
		for (r,row) in enumerate(img):
 
			for (c,pix) in enumerate(row):
 
@@ -138,19 +230,32 @@ class HoughTransform:
 
		colors=[[0,255,255],[255,0,255],[255,255,0]]
 
		color=colors[colorKey]
 
		(a,b,c,d)=params
 
		(h,w)=img.shape[:2]
 
		curve=lambda x: a*x**3+b*x**2+c*x+d
 
		for x in range(0,w,3):
 
			y=int(curve(x))
 
			y=round(curve(x))
 
			if y<0 or y>=2*h: continue
 
			if y<h:	img[y,x]=color
 
			else: img[y%h,-x]=color
 

	
 
	def drawLine(self,img,line,colorKey=0):
 
		colors=[[0,255,255],[255,0,255],[255,255,0]]
 
		color=colors[colorKey]
 
		(h,w)=img.shape[:2]
 
		(a,b,c)=line.toNormal()
 
		print("%",a,b,c)
 
		if b==0: return
 
		for x in range(1,w,3):
 
			y=round((-c-a*x)/b) + (0 if b>=0 else 180)
 
			if y<0 or y>=h: continue
 
			img[y,x]=color
 

	
 

	
 
def findPeaks(arr2d): # a naive implementation
 
	"""Scan 8-neighbourhood and for each peak or top plateau yield one point. For plateaus yield the """
 
	(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):
 
		for c in range(w):
 
			if all(r+dr<0 or r+dr>=h or c+dc<0 or c+dc>=w or arr2d[r,c]>arr2d[r+dr,c+dc] or (i<4 and arr2d[r,c]>=arr2d[r+dr,c+dc]) for (i,(dr,dc)) in enumerate(neighbours)):
 
				yield (r,c)
 
@@ -204,38 +309,6 @@ def houghLines(bwImg):
 
	if lines is None: lines=[]
 
	for line in lines:
 
		x1,y1,x2,y2 = line[0]
 
		cv.line(colorImg,(x1,y1),(x2,y2),(0,255,0),1)
 

	
 
	show(colorImg)
 

	
 

	
 
if __name__=="__main__":
 
	i=sys.argv[1]
 
	annotations=DataFile("/home/laman/Projekty/python/oneEye/images/annotations.json.gz")
 
	filename="{0}.jpg".format(i)
 
	img=cv.imread(os.path.join("/home/laman/Projekty/python/oneEye/images/",filename))
 
	(x1,y1,x2,y2)=computeBoundingBox(annotations[filename][0])
 
	img=img[y1:y2, x1:x2, :]
 
	# blurred=cv.GaussianBlur(img,(5,5),0)
 
	# small=cv.resize(img,None,fx=0.5,fy=0.5,interpolation=cv.INTER_AREA)
 
	small=img
 
	clahe = cv.createCLAHE(clipLimit=2.0, tileGridSize=(8,8))
 
	gray=cv.cvtColor(small,cv.COLOR_BGR2GRAY)
 
	# gray=clahe.apply(gray)
 
	show(gray)
 
	edges=cv.Canny(gray,70,130)
 
	show(edges)
 
	edges=filterHor(edges)+filterVert(edges)+filterDiag(edges)
 
	show(edges)
 

	
 

	
 
	# kernel = np.ones((2,2),np.uint8)
 
	# edges = cv.morphologyEx(edges, cv.MORPH_DILATE, kernel)
 
	# show(edges)
 
	# edges=cv.morphologyEx(edges,cv.MORPH_ERODE,kernel)
 
	# show(edges)
 
	colorEdges=cv.cvtColor(edges,cv.COLOR_GRAY2BGR)
 

	
 
	# houghLines(edges)
 
	h=HoughTransform(edges)
 
	h.extract()
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