Code review!

ResizeDemo.py

@@ -18,42 +18,42 @@
 sc = SeamCarverLib.SeamCarver(pic)
 
 print "print vertical seam 1"
-print sc.width(), sc.height()
+print sc._width, sc._height
 #SeamCarverUtilities.printVerticalSeamEnergy(sc)
-SeamCarverUtilities.printVerticalSeam(sc)
+SeamCarverUtilities.printSeam(sc, direction="vertical")
 #SeamCarverUtilities.distToArray(sc)
 
 print "remove vertical seam"
-s = sc.findVerticalSeam()
+s = sc.findSeam(direction="vertical")
 sc.removeVerticalSeam(s)
-print sc.width(), sc.height()
+print sc._width, sc._height
 print "find vertical seam"
-SeamCarverUtilities.printVerticalSeam(sc)
+SeamCarverUtilities.printSeam(sc, direction="vertical")
 
 print "print horizontal seam"
-SeamCarverUtilities.printHorizontalSeam(sc)
+SeamCarverUtilities.printSeam(sc, direction="horizontal")
 #SeamCarverUtilities.distToArray(sc)
 #SeamCarverUtilities.printHorizontalSeamEnergy(sc)
 
 print "remove horizontal seam"
-s = sc.findHorizontalSeam()
+s = sc.findSeam(direction="horizontal")
 sc.removeHorizontalSeam(s)
-print sc.width(), sc.height()
+print sc._width, sc._height
 #SeamCarverUtilities.printHorizontalSeamEnergy(sc)
 print "find horizontal seam"
-SeamCarverUtilities.printHorizontalSeam(sc)
+SeamCarverUtilities.printSeam(sc, direction="horizontal")
 #SeamCarverUtilities.distToArray(sc)
 
 
 # s = sc.findVerticalSeam()				
 # sc.removeVerticalSeam(s)
 
 # # print "print vertical seam 2"
-# print sc.width(), sc.height()
+# print sc._width, sc._height
 # SeamCarverUtilities.printVerticalSeam(sc)
 # #SeamCarverUtilities.printVerticalSeamEnergy(sc)			
 # # s = sc.findVerticalSeam()
-# # for i in range(sc.height()):
+# # for i in range(sc._height):
 # # 	print s[i]
 # # # print sc._edgeTo
 # # # print sc._distTo
@@ -62,42 +62,42 @@
 
 # s = sc.findVerticalSeam()
 # sc.removeVerticalSeam(s)
-# print sc.width(), sc.height()
+# print sc._width, sc._height
 
 # # print "print vertical seam 3"
-# # print sc.width(), sc.height()
+# # print sc._width, sc._height
 # SeamCarverUtilities.printVerticalSeam(sc)
 # SeamCarverUtilities.distToArray(sc)
 # #SeamCarverUtilities.printVerticalSeamEnergy(sc)			
 # # s = sc.findVerticalSeam()
-# # for i in range(sc.height()):
+# # for i in range(sc._height):
 # # 	print s[i]
 
 # s = sc.findVerticalSeam()
 # sc.removeVerticalSeam(s)
-# print sc.width(), sc.height()
+# print sc._width, sc._height
 
 # # print "print vertical seam 4"
-# # print sc.width(), sc.height()
+# # print sc._width, sc._height
 # SeamCarverUtilities.printVerticalSeam(sc)
 #SeamCarverUtilities.printVerticalSeamEnergy(sc)			
 # s = sc.findVerticalSeam()
-# for i in range(sc.height()):
+# for i in range(sc._height):
 # 	print s[i]
 
 # print "print vertical seam 2"
 # # print sc._edgeTo
 # # print sc._distTo
 # s = sc.findVerticalSeam()
 # sc.removeVerticalSeam(s)  							
-# print sc.height(), sc.width()	
+# print sc._height, sc._width	
 #SeamCarverUtilities.printVerticalSeam(sc) 			
 # print
 
 # print "print vertical seam 3"
 # s = sc.findVerticalSeam()							
 # sc.removeVerticalSeam(s) 							
-# print sc.height(), sc.width()
+# print sc._height, sc._width
 # # print sc._edgeTo
 # # print sc._distTo					
 # #pdb.set_trace()
@@ -107,15 +107,15 @@
 # print "remove vertical seam 4"
 # s = sc.findVerticalSeam()
 # sc.removeVerticalSeam(s)
-# print sc.height(), sc.width()
+# print sc._height, sc._width
 # # print sc._edgeTo
 # # print sc._distTo
 # SeamCarverUtilities.printVerticalSeam(sc)
 
 # print "remove vertical seam 5"
 # s = sc.findVerticalSeam()
 # sc.removeVerticalSeam(s)
-# print sc.height(), sc.width()
+# print sc._height, sc._width
 # SeamCarverUtilities.printVerticalSeam(sc)
 
 

SeamCarverLib.py

@@ -6,7 +6,7 @@
 import pdb
 
 class SeamCarver(object):
-	"removes seams from an image"
+	"""removes seams from an image"""
 	def __init__(self, picture):
 		self._img = picture.imageArray
 		self._height = picture.num_rows
@@ -25,24 +25,21 @@ def __init__(self, picture):
 		self._edgeTo = []
 		self._distTo = []
 
-
-	def width(self):
-		return self._width
-
-	def height(self):
-		return self._height
-
 	def energy(self, col, row):
-		"return energy of pixel in (col, row)"
+		"""return energy of pixel in (col, row)"""
 		if self._isValid(col, row):
 			return self._energy[self._toLinear(col, row)]
+		else:
+			print "invalid coordinates to energy: %s %s" % (col, row)
 
-	def findVerticalSeam(self, transposed=False):
-		"return vertical seam in image"
+	def findSeam(self, direction):
+		"""return vertical seam in image"""
 		# vertical seam = sequence of cols; seam[0] is col of row 0
-		# row-indexed seam
-		seam = [-1 for _ in range(self._height)]
-		self._buildGraph(transposed)
+		# 	- row-indexed seam
+		# horizontal seam = sequence of rows; seam[0] is row of col 0
+		#   - col-indexed seam
+		seam = [-1] * self._height
+		self._buildGraph(direction)
 		row = self._height - 1
 		v = self._edgeTo[self._sink]
 		while (v != self._source):
@@ -53,21 +50,8 @@ def findVerticalSeam(self, transposed=False):
 		#self._distTo = []
 		return seam
 
-	def findHorizontalSeam(self, transposed=True):
-		"return horizontal seam in image"
-		# tranpose dimensions
-		self._exchDims()
-
-		# horizontal seam = sequence of rows; seam[0] is row of col 0
-		# col-indexed seam
-		seam = self.findVerticalSeam(transposed)
-		self._exchDims()
-		#self._edgeTo = []
-		#self._distTo = []
-		return seam
-
 	def _shiftImgUp(self, (col, row)):
-		"remove horizontal seam in img and energy array by shifting up each col"
+		"""remove horizontal seam in img and energy array by shifting up each col"""
 		for r in range(row, self._height - 1):
 			i = self._width * r + col
 			rchan_index = i*3
@@ -77,7 +61,7 @@ def _shiftImgUp(self, (col, row)):
 			self._energy[i] = self._energy[i + self._width]
 
 	def _removeSeam(self, seam):
-		"remove seam of pixels from image"
+		"""remove seam of pixels from image"""
 		# remove horizontal seam
 		if(len(seam)) != self._width or self._width < 2:
 			raise ValueError
@@ -91,7 +75,7 @@ def _removeSeam(self, seam):
 
 
 	def removeVerticalSeam(self, seam):
-		"remove vertical seam of pixels from image"
+		"""remove vertical seam of pixels from image"""
 		if (len(seam) != self._height or self._height == 0 or self._width == 2):
 			raise ValueError
 		indexes_to_remove = map(lambda (r, col): self._width * r + col, enumerate(seam))
@@ -128,7 +112,7 @@ def removeVerticalSeam(self, seam):
 		self._sink = self._source + 1
 
 	def removeHorizontalSeam(self, seam):
-		"remove horizontal seam of pixels"
+		"""remove horizontal seam of pixels"""
 		self._removeSeam(seam)
 
 		# update energy
@@ -147,13 +131,13 @@ def removeHorizontalSeam(self, seam):
 
 
 	def _onEdge(self, col, row):
-		"True if pixel is on left, top, or right edge"
+		"""True if pixel is on left, top, or right edge"""
 		return col == 0 or col == self._width - 1 or row == 0
 
 	def _updateEnergy(self, R_chan, resized_width):
-		'''re-calculate energy values for pixels on either side of seam
+		"""re-calculate energy values for pixels on either side of seam
 
-		R_chan is a list of R channels'''
+		R_chan is a list of R channels"""
 		for R in R_chan:
 			# index = index of seam pixel wrt original image
 			index = R / self._num_channels
@@ -199,9 +183,9 @@ def _updateEnergy(self, R_chan, resized_width):
 					self._energyGrad(resized_index - 1, resized_width)
 
 	def _energyGrad(self, index, width):
-		'''Calculate energy of pixel in resized image. Update self._energy
+		"""Calculate energy of pixel in resized image. Update self._energy
 
-		uses resized_index and resized_width'''
+		uses resized_index and resized_width"""
 
 		left = (index  - 1) * self._num_channels
 		right = (index + 1) * self._num_channels
@@ -230,19 +214,13 @@ def _energyGrad(self, index, width):
 	def _diff_squared(self, x, y):
 		return (x - y)**2
 
-	def _exchDims(self):
-		"exchange self._width and self._height"
-		swap = self._width
-		self._width = self._height
-		self._height = swap
-
 	def _toLinear(self, col, row):
-		"converts pixel from (col, row) to single index"
+		"""converts pixel from (col, row) to single index"""
 		if self._isValid(col, row):
 			return row * self._width + col
 
 	def _toGrid(self, num):
-		"converts pixel from single index to (col, row)"
+		"""converts pixel from single index to (col, row)"""
 		if self._isValid(num):
 			row = num / self._width
 			col = num % self._width
@@ -260,8 +238,8 @@ def _isValid(self, col, row=None):
 			else:
 				return True
 
-	def _buildGraph(self, transposed):
-		"pixels are nodes; edges define precedence constraints in a seam"
+	def _buildGraph(self, direction):
+		"""pixels are nodes; edges define precedence constraints in a seam"""
 		# graph data structures
 		self._edgeTo = [_SENTINEL for _ in range(self._num_pixels + 2)]	# add 2 for source, sink pixels
 		self._distTo = [_INF for _ in range(self._num_pixels + 2)]
@@ -276,59 +254,60 @@ def _buildGraph(self, transposed):
 		# for each vertex (pixel), calculate edgeTo[], distTo[]
 		# start at row 1
 		for v in range(self._width, self._num_pixels):
-			if (v % self._width == 0):
-				# pixel is on left edge
-				self._edgeTodistTo(v, transposed, edgeL=True)
-			elif (v % self._width == self._width - 1):
-				# pixel is on right edge
-				self._edgeTodistTo(v, transposed, edgeR=True)
-			else:
-				self._edgeTodistTo(v, transposed)
+			edges = []
+			if v % self._width == 0:
+				edges.append('left')
+			if v % self._width == self._width - 1:
+				edges.append("right")
+			if v / self._width == 0:
+				edges.append("top")
+			if v / self._width == self._height - 1:
+				edges.append("bottom")
+
+			if direction == "vertical" and "top" in edges:
+				continue
+			if direction == "horizontal" and "left" in edges:
+				continue
+
+			self._edgeTodistTo(v, direction, edges)
+
 		# edgeTo[sink] is vertex in last row with min energy
 		index, min_energy = min(enumerate(self._distTo[self._num_pixels - self._width:self._num_pixels]), key=lambda (x, y): y)
 		self._distTo[self._sink] = min_energy
 		self._edgeTo[self._sink] = (self._height - 1) * self._width + index
 
 
 
-	def _edgeTodistTo(self, v, transposed, edgeL=False, edgeR=False):
+	def _edgeTodistTo(self, pixel, direction, edges):
 		# returns pixel connected to v with min energy
-		if edgeL:
-			# left edge
-			vC = v - self._width
-			vRD = v - self._width + 1
-			vLU = vC
-		elif edgeR:
-			# right edge
-			vLU = v - self._width - 1
-			vC = v - self._width
-			vRD = vC
-		else:
-			# pixels connect to v
-			vLU = v - self._width - 1
-			vC = v - self._width
-			vRD = v - self._width + 1
-
-		# energy of pixels connected to v
-		if transposed:
-			(colU, rowU) = self._toGrid(vLU)
-			(colC, rowC) = self._toGrid(vC)
-			(colD, rowD) = self._toGrid(vRD)
-			# read energy
-			eLU = self._energy[self._height * colU + rowU]
-			eC = self._energy[self._height * colC + rowC]
-			eRD = self._energy[self._height * colD + rowD]		
-		else:
-			# read energy directly from energy array
-			eLU = self._energy[vLU]
-			eC = self._energy[vC]
-			eRD = self._energy[vRD]
-			#print (eLU, vLU), (eC, vC), (eRD, vRD)
+
+		if direction == "vertical":
+			ancestor_one = pixel - self._width - 1
+			ancestor_two = pixel - self._width
+			ancestor_three = pixel - self._width + 1
+			if 'left' in edges:
+				ancestor_one = ancestor_two
+			elif 'right' in edges:
+				ancestor_three = ancestor_two
+
+		else: #horizontal
+			ancestor_one = pixel + self._width - 1
+			ancestor_two = pixel - 1
+			ancestor_three = pixel - self._width - 1
+			if 'top' in edges:
+				ancestor_three = ancestor_two
+			elif 'bottom' in edges:
+				ancestor_one = ancestor_two
+
+		eLU = self._energy[ancestor_one]
+		eC = self._energy[ancestor_two]
+		eRD = self._energy[ancestor_three]
+			#print (eLU, ancestor_one), (eC, ancestor_two), (eRD, ancestor_three)
 		# find min distance and its associated vertex
-		dist, from_vertex = min((self._distTo[vLU] + eLU, vLU), (self._distTo[vC] + eC, vC), (self._distTo[vRD] + eRD, vRD))
-		#e, vertex = min([(eC, vC), (eLU, vLU), (eRD, vRD)])
-		self._edgeTo[v] = from_vertex
-		self._distTo[v] = dist
+		dist, from_vertex = min((self._distTo[ancestor_one] + eLU, ancestor_one), (self._distTo[ancestor_two] + eC, ancestor_two), (self._distTo[ancestor_three] + eRD, ancestor_three))
+		#e, vertex = min([(eC, ancestor_two), (eLU, ancestor_one), (eRD, ancestor_three)])
+		self._edgeTo[pixel] = from_vertex
+		self._distTo[pixel] = dist