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Convert an image of a map into its generated tile-set.Command line args: tileWidth, tileHeight, fileexample:python Image2Map.py 16 16 map.png
# Filename : Image2Map.py
# Authors : Alex Swan, Georg Muntingh and Bjorn Lindeijer
# Version : 1.3
# Date : June 17, 2013
# Copyright : Public Domain
import os, sys, networkx
from PIL import Image
class TileMap:
""" This class represents a map of tiles.
"""
def __init__(self, file, tileX, tileY):
# For initialization, map image with filename file should be specified, together with the
# tile size (tile X, tileY). First we set the tile sizes.
self.TileX, self.TileY = tileX, tileY
# Open the map and find its attributes.
print "Opening the map image file: " + file
self.MapImage = Image.open(file)
self.MapImageWidth, self.MapImageHeight = self.MapImage.size
self.Width, self.Height = self.MapImageWidth / self.TileX, self.MapImageHeight / self.TileY
# Store the unique tiles in a list and a hash, and the map in a list.
self.MapList, self.TileList, self.TileDict = self.parseMap()
# Create a graph that contains the information that is relevant for the article.
self.graphFromList()
# We create a dictionary self.FullTileMap whose keys will be the coordinates
# for the image of unique tiles, and the values are the unique tile numbers.
self.FullTileMap = {}
# Extract maximal components from G into the dictionary TileMap, and combine them
# into self.FullTileMap using a method that places them as close to each other as
# possible.
while self.G.nodes() != []:
v = self.G.nodes()[0]
TileMap, K = self.growTileMap({(0, 0): v}, self.G, 0, 0, v)
self.FullTileMap = self.composeDictionaries(self.FullTileMap, TileMap)
self.G.remove_nodes_from(TileMap.values())
# Create an image file from our map of unique tiles.
self.TileImage = self.getTileImage()
def parseMap(self):
""" This function takes the map image, and obtains
* a list TList of unique tiles.
* a hash TDict of unique tiles.
* a double list self.MapList of where an entry equals i if
self.TileList[i] is the corresponding picture on the map image.
"""
MList = [[-1 for i in range(self.Width)] for j in range(self.Height)] # TODO: Make this a single list
TList = []
TDict = {}
progress = -1
print "Parsing the Map: "
# Jump through the map image in 8 x 8-tile steps. In each step:
# * If the string of the tile is in the dictionary, place its value in map list MList[y][x].
# * Otherwise, add this tile to the list, and add its string to the dictionary with value "the
# number of elements in the list". Also place this value in MList[y][x].
for y in range(self.Height):
for x in range(self.Width):
box = self.TileX * x, self.TileY * y, self.TileX * (x+1), self.TileY * (y+1)
tile = self.MapImage.crop(box)
s = tile.tostring()
if TDict.has_key(s):
MList[y][x] = TDict[s]
else:
TList.append(tile)
TDict[s] = len(TList)
MList[y][x] = len(TList)
# Calculate the progress, and print it to the screen.
p = ((x + y * self.Width) * 100) / (self.Width * self.Height)
if progress != p:
progress = p
self.printProgress(progress)
self.printProgress(100)
print "Done!"
return MList, TList, TDict
def printProgress(self, percentage):
""" This function prints the percentage on the current row after erasing what is already there.
"""
print '%s\r' % ' '*20, # clean up row
print '%3d%% ' % percentage, # ending with comma prevents newline from being appended
sys.stdout.flush()
def getTileImage(self):
""" This function takes the hash of unique tiles self.FullTileMap and
creates a tileset image from it.
"""
H = self.FullTileMap
Xmin = min([ h[1] for h in H.keys() ])
Xmax = max([ h[1] for h in H.keys() ])
Ymin = min([ h[0] for h in H.keys() ])
Ymax = max([ h[0] for h in H.keys() ])
TileImage = Image.new("RGB", (self.TileX * (Xmax - Xmin + 1), self.TileY * (Ymax - Ymin + 1) ) )
for i in range(Ymin, Ymax + 1):
for j in range(Xmin, Xmax + 1):
if (i,j) in H:
box = ( self.TileX * (j - Xmin) , self.TileY * (i - Ymin), \
self.TileX * (j - Xmin + 1), self.TileY * (i - Ymin + 1) )
TileImage.paste(self.TileList[H[(i,j)] - 1].convert("RGB"), box)
return TileImage
def printHash(self, H):
""" This function nicely aligns dictionaries with elements of the form
"(y, x): n" in a table, in which row y, column x has entry n.
In this specific case (x, y) will be the tile coordinates at which
tile n will be placed in the tile image.
"""
Xmin = min([ h[1] for h in H.keys() ])
Xmax = max([ h[1] for h in H.keys() ])
Ymin = min([ h[0] for h in H.keys() ])
Ymax = max([ h[0] for h in H.keys() ])
# Find the number of symbols we need to write down the tile numbers.
D = len(str(max(H.values())))
st = ""
for i in range(Ymin, Ymax + 1):
for j in range(Xmin, Xmax + 1):
if not (i,j) in H:
st = st + "|"
for k in range(D):
st = st + "."
else:
h = H[(i,j)]
d = len(str(h))
st = st + "|"
for k in range(D-d):
st = st + "."
st = st + str(h)
st = st + "|\n"
print st
def addEdge(self, s, t, dir):
""" This function increases abs(value) of an edge st in a graph G, taking the
'direction' of st into account.
s: a start vertex
t: an end vertex
dir: a value depicting the st-direction,
+1 for left -> right
-1 for up -> down
"""
if self.G.has_edge(s, t):
values = [ value for value in self.G.get_edge_data(s, t) if (dir * value) > 0 ]
else:
values = []
if values:
self.G.remove_edge(s, t, values[0]) # increase the value by 1
self.G.add_edge(s, t, values[0] + dir)
else:
self.G.add_edge(s, t, dir) # create a dir-valued edge
def graphFromList(self):
""" This function constructs a weighted directed graph from the
list that depicts the map using the following scheme:
Left A, Right B -> add (A, B, 1)
Left B, Right A -> add (B, A, 1)
Up A, Down B -> add (A, B,-1)
Up B, Down A -> add (B, A,-1)
We then add all similar edges together, so for instance
(A, B, 1) and (A, B, 1) -> (A, B, 2)
but *NOT*
(A, B, 1) and (A, B, -1) -> (A, B, 0)
"""
self.G = networkx.MultiDiGraph(selfloops = False, multiedges = True)
L = self.MapList
progress = -1
print "Generating the graph: "
# Now add for every Cartesian crossing an edge (or a value) in G
for i in range(len(L) - 1):
for j in range(len(L[0]) - 1):
self.addEdge(L[i][j], L[i][j + 1], 1) # L-R, +1
self.addEdge(L[i][j], L[i + 1][j], -1) # U-D, -1
# Calculate the progress, and print it to the screen.
p = ((j + i * len(L)) * 100) / (len(L) * len(L[0]))
if progress != p:
progress = p
self.printProgress(progress)
# What remains is the bottom and right line of edges:
for j in range(len(L[0]) - 1):
self.addEdge(L[len(L) - 1][j], L[len(L) - 1][j + 1], 1)
for i in range(len(L) - 1):
self.addEdge(L[i][len(L[0]) - 1], L[i + 1][len(L[0]) - 1], -1)
# Now show 100% progress and say we're done.
self.printProgress(100)
print "Done!"
def growTileMap(self, TileMap, G, posX, posY, curV):
""" This is a recursive function that arranges a map of unique tiles.
"""
# For each of the directions, make a possible edge-list to choose from,
# and combine them into one list Edges such that Edges[i] stands
# for the edges with direction code i, where
# 0 <-> up
# 1 <-> right
# 2 <-> down
# 3 <-> left
LL = [e for e in G.in_edges(curV, keys=True, data=True) if e[2] > 0]
LU = [e for e in G.in_edges(curV, keys=True, data=True) if e[2] < 0]
LR = [e for e in G.out_edges(curV, keys=True, data=True) if e[2] > 0]
LD = [e for e in G.out_edges(curV, keys=True, data=True) if e[2] < 0]
Edges = [LU, LR, LD, LL]
# We want to visit all directions such that we visit the direction with
# the smallest amount of possible tiles first. This is because these tiles
# will have the smallest probability to fit in at a later stage. It will
# also embed blocks of tiles that appear only in one configuration
# (pictures chopped up in tiles).
dir = [ [ Edges[i], i ] for i in range(4)]
dir.sort(cmp = lambda L1, L2: len(L1[0]) - len(L2[0]))
dir = [ x[1] for x in dir]
while dir != []:
direction = dir[0]
if Edges[direction] != []:
E = Edges[direction]
# Now order E with respect to the values of its edges. This will
# make the algorithm start with a combination that appears most
# often in the graph, which is a measure for how much two tiles
# "belong together".
E.sort(cmp = lambda e, f: abs(e[2]) - abs(f[2]), reverse = True)
# Now walk through E until you find an edge that fits with
# the previously placed tiles in TileMap
isPlaced = False
while E != [] and isPlaced == False:
e = E[0]
# We need to know the end vertex and the new position.
if direction == 0:
endV = e[0]
NX, NY = posX, posY - 1
elif direction == 1:
endV = e[1]
NX, NY = posX + 1, posY
elif direction == 2:
endV = e[1]
NX, NY = posX, posY + 1
elif direction == 3:
endV = e[0]
NX, NY = posX - 1, posY
# Now in case position NX, NY is not already taken and endV is
# compatible with "surrounding edges" in our graph, then we can
# add endV to our TileMap.
if (not (NY, NX) in TileMap) and (TileMap.values().count(endV) == 0) and \
( (not (NY-1, NX) in TileMap) or G.has_edge(TileMap[(NY-1, NX)], endV) ) and \
( (not (NY, NX+1) in TileMap) or G.has_edge(endV, TileMap[(NY, NX+1)]) ) and \
( (not (NY+1, NX) in TileMap) or G.has_edge(endV, TileMap[(NY+1), NX]) ) and \
( (not (NY, NX-1) in TileMap) or G.has_edge(TileMap[(NY, NX-1)], endV) ):
# Add this node to our TileMap and delete the edge we just processed.
TileMap[(NY, NX)] = endV
isPlaced = True
G.remove_edge(e[0], e[1])
# Call the procedure recursively with this new node.
TileMap, G = self.growTileMap(TileMap, G, NX, NY, endV)
E = E[1:len(E)] # Chop of the first edge
dir = dir[1:len(dir)] # Chop of the first direction
return TileMap, G
def centerOfDictionary(self, H):
""" Returns the center of the dictionary, that is, the average of all keys.
"""
L = H.keys()
return [ int(round( sum([l[1] for l in L]) / (len(L) + 0.0) )), \
int(round( sum([l[0] for l in L]) / (len(L) + 0.0) )) ]
def composeDictionaries(self, H1, H2):
""" This method takes two dictionaries H1, H2 that represent pieces of the
maps of unique tiles, and pastes the second into the first, as close to
their centers -- as close together -- as possible.
"""
# In the first step H1 will be empty, and we return just H2.
if H1 == {}:
return H2
CX1, CY1 = self.centerOfDictionary(H1)
CX2, CY2 = self.centerOfDictionary(H2)
# To make sure we fit H2 in as central as possible in H1, we walk in a spiral
# around the center of H1, the offset being X, Y.
# |.4|.5|.6|
# |.3|.0|.7|
# |.2|.1|.8|
# ...|.9|
X, Y = 0, 0
foundFit = False
while foundFit == False:
# We check if H2 can be placed at location (CX1 + X, CY1 + Y)
isFit = True
keys = H2.keys()
# As long as there are keys in H2 left and we found no counter example:
while keys != [] and isFit:
(y, x) = keys.pop()
x1, y1 = x - CX2 + CX1 + X, y - CY2 + CY1 + Y
if H1.has_key((y1, x1)) or H1.has_key((y1 - 1, x1)) or H1.has_key((y1, x1 + 1)) or \
H1.has_key((y1 + 1, x1)) or H1.has_key((y1, x1 - 1)):
isFit = False
# If we found a fit, embed H2 into H1 accordingly.
if isFit:
for (y, x) in H2.keys():
x1, y1 = x - CX2 + CX1 + X, y - CY2 + CY1 + Y
H1[(y1, x1)] = H2[(y, x)]
foundFit = True
# Update the offset (X, Y) from the center of H1, by spiraling away.
if X == 0 and Y == 0:
Y += 1 # The first direction away from (0,0)
elif Y < 0 and X < -Y and X >= Y:
X += 1
elif X > 0 and Y <= X and Y >= -X:
Y += 1
elif Y > 0 and X > -Y and X < Y:
X -= 1
elif X < 0 and Y > X and Y <= -X:
Y -= 1
return H1
if sys.argv[1] == "--help":
print "Usage : python Image2Map.py [tileX] [tileY] files..."
print "Example: python Image2Map.py 8 8 Sewers.png Caves.png"
elif len(sys.argv) < 4:
print "Error : You specified too few arguments!\n"
print "Usage : python Image2Map.py [tileX] [tileY] files..."
print "Example: python Image2Map.py 8 8 Sewers.png Caves.png"
else:
tileX, tileY = int(sys.argv[1]), int(sys.argv[2])
for file in sys.argv[3:]:
map = TileMap(file, tileX, tileY)
tilefile = os.path.splitext(file)[0] + "-Tileset" + ".png"
print "Saving the tileset image into the file: " + tilefile
map.TileImage.save( tilefile, "PNG" )
print "Pretty-printing the tileset:" + "\n"
map.printHash(map.FullTileMap)
@ShinuToki
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In lines 108 and 115, I think it would be better to use "RGBA" instead of "RGB", so it would be possible to use maps with transparencies.

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