Đếm số lượng nhóm 1 trong bản đồ bumpean.array

Bây giờ tôi đang xử lý một số xử lý hình ảnh trong Python thông qua PIL (Thư viện hình ảnh Python). Mục đích chính của tôi là đếm số lượng tế bào màu trong hình ảnh hóa mô miễn dịch. Tôi biết rằng có các chương trình, thư viện, chức năng và hướng dẫn liên quan về nó và tôi đã kiểm tra hầu hết tất cả chúng. Mục đích chính của tôi là viết mã thủ công từ đầu, càng nhiều càng tốt. Do đó tôi đang cố gắng tránh sử dụng nhiều thư viện và chức năng bên ngoài. Tôi đã viết hầu hết các chương trình. Vì vậy, đây là những gì đang diễn ra từng bước:

Chương trình có trong tập tin hình ảnh:

Và xử lý nó cho các ô màu đỏ (về cơ bản, nó sẽ tắt các giá trị RGB dưới một ngưỡng nhất định cho màu đỏ):

Và tạo bản đồ boolean của nó, (sẽ dán một phần của nó vì nó lớn) mà về cơ bản chỉ cần đặt 1 bất cứ nơi nào nó gặp một pixel màu đỏ trong hình ảnh thứ hai được xử lý ở trên.

22222222222222222222222222222222222222222
20000000111111110000000000000000000000002
20000000111111110000000000000000000000002
20000000111111110000000000000000000000002
20000000011111100000000000000000001100002
20000000001111100000000000000000011111002
20000000000110000000000000000000011111002
20000000000000000000000000000000111111002
20000000000000000000000000000000111111102
20000000000000000000000000000001111111102
20000000000000000000000000000001111111102
20000000000000000000000000000000111111002
20000000000000000000000000000000010000002
20000000000000000000000000000000000000002
22222222222222222222222222222222222222222

Tôi cố tình tạo khung hình giống như vật ở biên giới với 2 giây để giúp tôi đếm số nhóm 1 trong bản đồ boolean đó.

Câu hỏi của tôi cho các bạn là, tại sao tôi có thể đếm số lượng tế bào (nhóm 1) một cách hiệu quả trong loại bản đồ boolean đó? Tôi đã tìm thấy http://en.wikipedia.org/wiki/Connected-component_labeling trông cực kỳ liên quan và tương tự nhau, nhưng theo như tôi thấy, nó ở cấp độ pixel. Của tôi là ở cấp độ boolean. Chỉ cần 1 giây và 0 giây.

Cảm ơn rất nhiều.

Một cái gì đó của một cách tiếp cận mạnh mẽ, nhưng được thực hiện bằng cách đảo ngược vấn đề để lập chỉ mục trên các bộ sưu tập pixel để tìm các khu vực, thay vì rasterizing trên mảng.

data = """\
000000011111111000000000000000000000000
000000011111111000000000000000000000000
000000011111111000000000000000000000000
000000001111110000000001000000000110000
000000000111110000000011000000001111100
000000000011100000000000100000011111100
000000000000000000000000000000011111100
000000000000000000000000000000011111110
000000000000000000000000000000111111110
000000000000000000000000000000111111110
000000000000000000000000000000011111100
000000000000000000000000000000001000000
000000000000000000000000000000000000000"""

from collections import namedtuple
Point = namedtuple('Point', 'x y')

def points_adjoin(p1, p2):
    # to accept diagonal adjacency, use this form
    #return -1 <= p1.x-p2.x <= 1 and -1 <= p1.y-p2.y <= 1
    return (-1 <= p1.x-p2.x <= 1 and p1.y == p2.y or
             p1.x == p2.x and -1 <= p1.y-p2.y <= 1)

def adjoins(pts, pt):
    return any(points_adjoin(p,pt) for p in pts)

def locate_regions(datastring):
    data = map(list, datastring.splitlines())
    regions = []
    datapts = [Point(x,y) 
                for y,row in enumerate(data) 
                    for x,value in enumerate(row) if value=='1']
    for dp in datapts:
        # find all adjoining regions
        adjregs = [r for r in regions if adjoins(r,dp)]
        if adjregs:
            adjregs[0].add(dp)
            if len(adjregs) > 1:
                # joining more than one reg, merge
                regions[:] = [r for r in regions if r not in adjregs]
                regions.append(reduce(set.union, adjregs))
        else:
            # not adjoining any, start a new region
            regions.append(set([dp]))
    return regions

def region_index(regs, p):
    return next((i for i,reg in enumerate(regs) if p in reg), -1)

def print_regions(regs):
    maxx = max(p.x for r in regs for p in r)
    maxy = max(p.y for r in regs for p in r)
    allregionpts = reduce(set.union, regs)
    for y in range(-1,maxy+2):
        line = []
        for x in range(-1,maxx+2):
            p = Point(x, y)
            if p in allregionpts:
                line.append(str(region_index(regs, p)))
            else:
                line.append('.')
        print ''.join(line)
    print


# test against data set
regs = locate_regions(data)
print len(regs)
print_regions(regs)

Bản in:

4
........................................
........00000000........................
........00000000........................
........00000000........................
.........000000.........1.........33....
..........00000........11........33333..
...........000...........2......333333..
................................333333..
................................3333333.
...............................33333333.
...............................33333333.
................................333333..
.................................3......
........................................

Bạn có thể sử dụng ndimage.label, đó là một cách tốt đẹp để làm điều này. Nó trả về một mảng mới, với mỗi tính năng có một giá trị duy nhất và số lượng tính năng. Bạn cũng có thể chỉ định một yếu tố kết nối.

import scipy
from scipy import ndimage
import matplotlib.pyplot as plt

#flatten to make greyscale, using your second red-black image as input.
im = scipy.misc.imread('blobs.jpg',flatten=1)
#smooth and threshold as image has compression artifacts (jpg)
im = ndimage.gaussian_filter(im, 2)
im[im<10]=0
blobs, number_of_blobs = ndimage.label(im)
print 'Number of blobls:', number_of_blobs

plt.imshow(blobs)
plt.show()

#Output is:
Number of blobls: 30

Đây là một thuật toán O (tổng số pixel + số pixel của ô). Chúng tôi chỉ đơn giản là quét hình ảnh cho các pixel của ô và khi chúng tôi tìm thấy một hình ảnh, chúng tôi sẽ lấp đầy ô để xóa nó.

Triển khai trong Common Lisp, nhưng bạn sẽ có thể dịch nó sang Python một cách tầm thường.

(defun flood-fill (picture i j target-color replacement-color)
  ;; http://en.wikipedia.org/wiki/Flood_fill
  (when (= (aref picture i j) target-color)
    (setf (aref picture i j) replacement-color)
    (when (plusp i)
      (flood-fill picture (1- i) j target-color replacement-color))
    (when (< (1+ i) (array-dimension picture 0))
      (flood-fill picture (1+ i) j target-color replacement-color))
    (when (plusp j)
      (flood-fill picture i (1- j) target-color replacement-color))
    (when (< (1+ j) (array-dimension picture 1))
      (flood-fill picture i (1+ j) target-color replacement-color)))
  picture)


(defun count-cells (picture)
  (loop
    :with cell-count = 0
    :for i :from 0 :below (array-dimension picture 0)
    :do (loop
          :for j :from 0 :below (array-dimension picture 1)
          :unless (zerop (aref picture i j))
          :do (progn (incf cell-count)
                     (flood-fill picture i j 1 0)))
    :finally (return cell-count)))




(count-cells
  (make-array '(128 171) :element-type 'bit
              :initial-contents
              #(#171*000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000111111111000000000000000000000000000
                #171*000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000111111111000000000000000000000000000
                #171*000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000111111111000000000000000000001110000
                #171*000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000011111110000000000000000000011111100
                #171*000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000111000000000000000000000011111100
                #171*000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000111111100
                #171*000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000111111110
                #171*000000000001110000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000001111111110
                #171*000000000011111000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000001111111110
                #171*000000000011111100000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000001111111100
                #171*000000000011111110000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000001
                #171*000000000001111110000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000001
                #171*000000000001111110000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000011
                #171*000000000000011110000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000011
                #171*000000000000011000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000001
                #171*000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000011111000000000000000000011
                #171*000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000111111100000000000000000000
                #171*000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000111111100000000000000000000
                #171*000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000111111110000000000000000000
                #171*000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000001111000000000000000000000111111110000000000000000000
                #171*000000000000000000111111000000000000000000000000000000000000000000000000000000111110000000000000000000000000000000000001111111100001111000000000011111110000000000000000000
                #171*000000000000000000111111100000000000000000000000000000000000000000000000000011111110000000000000000000000000000000000111111111100011111100000000011111100000000000000000000
                #171*000000000000000000111111100000000000000000000000000000000000000000000000000011111110000000000000000000000000000000000111111111110111111110000000000100000000000000000000000
                #171*000000000000000000111111100000000000000000000000000000000000000000000000000011111100000000000000000000000000000000000111111111110111111110000000000000000000000000000000000
                #171*000000000000000000111111100000000000000000000000000000000000000000000000000011111100000000000000000000000000000000000011111111100111111110000000000000000000000000000000000
                #171*000000000000000000111111100000000000000000000000000000000000000000000000000011111100000000000000000000000000000000000001111111100111111110000000000000000000000000000000000
                #171*000000000000000000011111100000000000000000000000000000000000000000000000000011111001110000000000000000000000000000000000011111000011111110000000000000000000000000000000000
                #171*000000000000000000010110000000000000000000000000000000000000000000000000000000000011111000000000000000000000000000000000000000000000111010000000000000000000000000000000000
                #171*000000000000000000000000000000000000000000000000000000000000000000000000000000000111111100000000000000000000000000000000000000000000000000000000000000000000000000000000000
                #171*000000000000000000000000000000000000000000000000000000000000000000000000000000000111111110000000000000000000000000000000000000000000000000000000000000000000000000000000000
                #171*000000000000000000000000000000000000000000000000000000000000000000000000000000000111111111000000000000000000000000000000000000000000000000000000000000000000000000000000000
                #171*000000000000000000000000000000000000000000000000000000000000000000000000000000000111111111000000000000000000000000000000000000000000000000000000000000000000000000000000000
                #171*000000000000000000000000000000000000000000000000000000000000000000000000000000000111111111000000000000000000000000000000000000000000000000000000000000000000000000000000000
                #171*000000000000000000000000000000000000000000000000000000000000000000000000000000000011111111000000000000000000000000000000000000000000000000000000111100000000000000000000000
                #171*000000000000000000000000000000000000000000000111100000000000000000000000000000000000111100000000000000000000000000000000000000000000000000000011111111100000000000000000000
                #171*100000000000000000000000000000000000000000001111110000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000001111111100000000000000000000
                #171*111100000000000000000000000000000000000000011111111000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000001111111100000000000000000000
                #171*111100000000000000000000000000000000000000011111111100000000000000000000000000000000000000000000000000000000000000000000000000000000000000000001111111100000000000000000000
                #171*111100000000000000000000000000000000000000111111111110000000000000000000000000000000000000000000000000000000000000000000000000000000000000000001111111100000000000000000011
                #171*111100000000000000000000000000000000000000111111111110000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000011110000000000000000000111
                #171*111100000000000000000000000000000000000000011111111000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000111
                #171*000000000000000000000000000000000000000000011111110000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000011
                #171*000000000000000000000000000000000000000000000001100000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000011
                #171*000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000011
                #171*000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000001
                #171*000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000
                #171*000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000
                #171*000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000
                #171*000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000011111000000000
                #171*000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000111111100000000
                #171*000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000001111111100000000
                #171*000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000001111111100000000
                #171*000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000001111111100000000
                #171*000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000010000000000000000000000000000000000000000001111111100000000
                #171*000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000011111100000000000000000000000000000000000000000111111000000000
                #171*000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000011111111100000000000000000000000000000000000000111110000000000
                #171*000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000011111111100000000000000000000000000000000000000000000000000000
                #171*000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000111111110000000000000000000000000000000000000000000000000000
                #171*000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000111111110000000000000000000000000000000000000000000000000000
                #171*000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000011111110000000000000000000000000000000000000000000000000000
                #171*000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000110000000000000000000000000000000000000000000000000000000
                #171*000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000
                #171*000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000
                #171*000000000000000000000000000000011111000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000
                #171*000000000000000000000000000000111111110000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000
                #171*000000000000000000000000000001111111110000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000
                #171*000000000000000000000000000001111111110000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000
                #171*000000000000000000000000000001111111110000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000
                #171*000000000000000000000000000001111111110000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000
                #171*000000000000000000000000000000111111100000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000
                #171*000000000000000000000000000000011100000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000
                #171*000000000000000000000000000000000000000000000000000000000000000000000000000000010000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000
                #171*000000000000000000000000000000000000000000000000000000000000000000000000011111110000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000
                #171*000000000000000000000000000000000000000000000000000000000000000000000000111111110000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000
                #171*000000000000000000000000000000000000000000000000000000000000000000000000111111111000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000
                #171*000000000000000000000000000000000000000000000000000000000000000000000000011111111000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000
                #171*000000000000000000000000000000000000000000000000000000000000000000000000011111111000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000
                #171*000000000000000000000000000000000000000000000000000000000000000000000000011111111000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000
                #171*000000000000000000011000000000000000000000000000000000000000000000000000001111110000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000
                #171*000000000000000001111100000000000000000000000000000000000000000000000000000111100000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000
                #171*000000000000000011111110000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000
                #171*000000000000000111111110000000000000000000000000000000000000000011111100000000000000000000000000000000000000000000000000111111000000000000000000000000000000000000000000000
                #171*000000000000000111111111000000000000000000000000000000000000000011111100000000000000000000000000000000000000000000000001111111100000000000000000000000000000000000000000000
                #171*000000000000000111111110000000000000000000000000000000000000000111111110000000000000000000000000000000000000000000000001111111100000000000000000000000000000000000000000000
                #171*000000000000000111111110000000000000000000000000000000000000001111111110000000000000000000000000000000000000000000000001111111110000000000000000001111111000000000000000000
                #171*000000000000000011111110000000000000000000000000000000000000001111111110000000000000000000000000000000000000000000000001111111110000000000000000011111111100000000000000000
                #171*000000000000000001110000000000000000000000000000000000000000000111111110000000000000000000000000000000000000000000000000011111100000000000000000011111111100000000000000000
                #171*000000000000000000000000000000000000000000000000000000000000000111111100000000000000000000000000000000000000000000000000001111000000000000000000011111111100000000000000000
                #171*000000000000000000000000000000000000000000000000000000000000000011111000000000000000000000000000000000000000000000000000000000000000000000000000011111111100000000000000000
                #171*000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000011111111100000000000000000
                #171*000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000111000000000000000000000000000000000000000000001111111000000000000000000
                #171*000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000111111100000000000000000000000000000000000000000000100010000000000000000000
                #171*000000000000000000000000000000000000000000000000000000000000000000000000001111100000000000000000111111110000000000000000000000000000000000000000000000000000000000000000000
                #171*000000000000000000000000000000000000000000000000000000000000000000000000011111110000000000000011111111110000000000000000000000000000000000000000000000000000000000000000000
                #171*000000000000000000000000000000000000000000000000000000000000000000000000011111110000000000000011111111110000000000000000000000000000000000000000000000000000000000000000000
                #171*000000000000000000000000000000000000000000000000000000000000000000000000011111110000000000000011111111110000000000000000000000000000000000000000000000000000000000000000000
                #171*000000000000000000000000000000000000000000000000000000000000000000000000011111111000000000000011111111110000000000000000000000000000000000000000000000000000000000000000000
                #171*000000000000000000000000000000000000000000000000000000000000000000000000011111110000000000000011111111100000000000000000000000000000000000000000000000000000000000000000000
                #171*000000000000000000000000000000000000000000000000000000000000000000000000001111100000000000000010111111100000000000000000000000000000000000000000000000000000000000000000000
                #171*000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000011111000000000000000000000000000000000000000000000000000000000000000000000
                #171*000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000
                #171*000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000
                #171*000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000
                #171*000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000
                #171*000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000
                #171*000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000
                #171*000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000
                #171*000000000001111111000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000
                #171*000000000001111111110000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000
                #171*000000000001111111110000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000
                #171*000000000011111111110000000000000000000000000000000000000011111100000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000
                #171*000000000011111111110000000000000000000000000000000000000111111100000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000
                #171*000000000011111111110000000000000000000000000000000000001111111110000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000
                #171*000000000001111111110000000000000000000000000000000000001111111110000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000
                #171*000000000001111111000000000000000000000000000000000000001111111110000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000
                #171*000000000000000000000000000000000000000000000000000000000111111100000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000
                #171*000000000000000000000000000000000000000000000000000000000011111000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000
                #171*000000000000000000011111000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000
                #171*000000000000000000011111100000000000000000000000000000000000000001000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000
                #171*000000000000000001111111110000000000000110000000000000000000000001111110000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000
                #171*000000000000000001111111110000000000001111100000000000000000000011111110000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000
                #171*000000000000000001111111110000000000111111111000000000000000000011111111000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000
                #171*000000000000000000111111110000000000111111111000000000000000000111111111000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000
                #171*000000000000000000111111111000000000111111111100000000000000000111111111000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000
                #171*000000000000000000011111100001111000111111111100000000000000000111111110000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000
                #171*000000000000000000000000000111111100111111111100000000000000000011111100000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000
                #171*000000000000000000000000000111111100011111111100000000000000000001110000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000
                #171*000000000000000000000000001111111100011111110000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000)))
--> 30

Nhiều hơn một nhận xét mở rộng hơn là một câu trả lời:

Như @interjay đã gợi ý, trong một hình ảnh nhị phân, tức là một màu chỉ có 2 màu, các pixel lấy giá trị là 1 hoặc 0. Điều này có thể đúng hoặc không đúng trong định dạng biểu diễn hình ảnh bạn đang sử dụng nhưng đó là sự thật trong đại diện 'khái niệm' của hình ảnh của bạn; đừng để chi tiết thực hiện làm bạn bối rối về vấn đề này. Một trong những chi tiết triển khai đó là việc bạn sử dụng 2 giây xung quanh viền của hình ảnh - một cách hoàn toàn hợp lý để xác định vùng chết xung quanh hình ảnh, nhưng không ảnh hưởng đến chất lượng nhị phân của hình ảnh.

Đối với việc kiểm tra các pixel N, NE, NW và W: điều này liên quan đến việc kết nối các pixel trong quá trình hình thành thành phần. Mỗi pixel (thanh các trường hợp đặc biệt viền) có 8 lân cận (N, S, E, W, NE, NW, SE, SW) nhưng những pixel nào là ứng cử viên để đưa vào cùng một thành phần? Đôi khi các thành phần chỉ gặp nhau ở các góc (NE, NW, SE, SW) không được coi là kết nối, đôi khi chúng là.

Bạn phải quyết định những gì phù hợp cho ứng dụng của bạn. Tôi đề nghị bạn làm việc, bằng tay, một vài thao tác của thuật toán tuần tự, kiểm tra các hàng xóm khác nhau cho mỗi pixel, để cảm nhận về những gì đang diễn ra.