diff --git a/src/analyzer/__init__.py b/src/analyzer/__init__.py
--- a/src/analyzer/__init__.py
+++ b/src/analyzer/__init__.py
@@ -6,13 +6,28 @@ from util import BLACK,WHITE,EMPTY, expo
 log=logging.getLogger(__name__)
 
 
+class Params:
+	def __init__(self):
+		self.tresB=30
+		self.tresW=60
+		self.corners=[]
+
+	def copy(self):
+		res=Params()
+		res.tresB=self.tresB
+		res.tresW=self.tresW
+		res.corners=[p*1 for p in self.corners] # *1 forces copy
+		return res
+
+
 class ImageAnalyzer:
 	def __init__(self,tresB=30,tresW=60):
 		self.board=[[EMPTY]*19 for r in range(19)]
 		self.grid=None
 
-		self.tresB=tresB
-		self.tresW=tresW
+		self.params=Params()
+		self.params.tresB=tresB
+		self.params.tresW=tresW
 
 	# let's not concern ourselves with sizecoef and shift here anymore. we want corners to come already properly recomputed
 	def analyze(self,image):
@@ -43,8 +58,8 @@ class ImageAnalyzer:
 				I=(red+green+blue)/255/3
 				m=min(red,green,blue)
 				S=1-m/I if I!=0 else 0
-				if 100*I<self.tresB: b+=1
-				elif 100*I>self.tresW: w+=1
+				if 100*I<self.params.tresB: b+=1
+				elif 100*I>self.params.tresW: w+=1
 				else: e+=1
 
 		log.debug("(%d,%d) ... (b=%d,w=%d,e=%d)", row, col, b, w, e)
@@ -53,7 +68,13 @@ class ImageAnalyzer:
 		if w>=b and w>=e: return WHITE
 		return EMPTY
 
-	def setGridCorners(self,corners):
+	def setParams(self,params):
+		self.params=params.copy()
+		if len(params.corners)==4:
+			self.grid=Grid(self.params.corners)
+
+	def setCorners(self,corners):
+		self.params.corners=[p*1 for p in corners]
 		self.grid=Grid(corners)