Code: Alles auswählen
from collections import namedtuple
from operator import mul
import cv2
Info = namedtuple('Info', 'start height')
def max_size(mat, value=0):
it = iter(mat)
hist = [(el==value) for el in next(it, [])]
max_size = max_rectangle_size(hist)
for row in it:
hist = [(1+h) if el == value else 0 for h, el in zip(hist, row)]
max_size = max(max_size, max_rectangle_size(hist), key=area)
return max_size
def max_rectangle_size(histogram):
stack = []
top = lambda: stack[-1]
max_size = (0, 0) # height, width of the largest rectangle
pos = 0 # current position in the histogram
for pos, height in enumerate(histogram):
start = pos # position where rectangle starts
while True:
if not stack or height > top().height:
stack.append(Info(start, height)) # push
elif stack and height < top().height:
max_size = max(max_size, (top().height, (pos - top().start)),key=area)
start, _ = stack.pop()
continue
break # height == top().height goes here
pos += 1
for start, height in stack:
print 'pos',pos
print 'start',start
print 'height',height
max_size = max(max_size, (height, (pos - start)), key=area)
return max_size
def area(size):
return reduce(mul, size)
#Beispiel Binärbild:
#Y 0 1 2 X
arr = [[0, 0, 0, 0 ], #0
[0, 1, 0, 0 ], #1
[0, 0, 0, 0 ], #2
]
ausgabe = max_size(arr)
print ausgabe
#(3,2)
