how to vertically segment an image?-CodePudding

I have images like this:

Input image

where all objects are connected through a horizontal line. all the symbols have different widths so can't extract all shapes using a fixed width or splitting points like when we split an array.

In this image, there are 4 symbols but in some other cases it can be more or less than 4 so here also I can't perform something like "4 symbols so divide the input image width vertically into 4 different widths. so I don't know how to extract whatever symbols the image might have efficiently like this output I want

the output I want .

Can you guys help me with this?

to
output

CodePudding user response：

Let me give it to you in

with

col =

   130   243   351

CodePudding user response：

import urllib.request
from PIL import Image
from scipy import signal
import numpy as np
from matplotlib import pyplot as plt

urllib.request.urlretrieve(
  'https://i.stack.imgur.com/iMKIP.jpg',
   "img.png")
img = Image.open("img.png")
img.show()

arr = (np.array(img)<(255)/2) #I'm considering black parts as filled
plt.imshow(arr)

plt.subplot(211)
plt.imshow(arr, aspect="auto")
plt.subplot(212)
plt.plot(arr.sum(axis=0))
plt.xlim(0,arr.shape[1])

Then, in order to find local min:

x_lines = signal.find_peaks(-arr.sum(axis=0))[0]

plt.imshow(arr, aspect="auto")
plt.vlines(x_lines, 0, arr.shape[0], color="r")

Finally if we consider a threshold (for example 50 filled pixel in columns):

threshold = 50

x_lines = signal.find_peaks(-arr.sum(axis=0))[0]
x_lines = x_lines[arr.sum(axis=0)[x_lines]<threshold]

plt.imshow(arr, aspect="auto")
plt.vlines(x_lines, 0, arr.shape[0], color="r")