Detect dotted (broken) lines only in an image using OpenCV

[Edu Py]

I am trying to learn techniques on image feature detection.

I have managed to detect horizontal line(unbroken/continuous), however I am having trouble detecting all the dotted/broken lines in an image.

Here is my test image, as you can see there are dotted lines and some text/boxes etc.


my code is below:

import cv2
import numpy as np

img=cv2.imread('test.jpg')
img=functions.image_resize(img,1000,1000) #function from a script to resize image to fit my screen
imgGray=cv2.cvtColor(img,cv2.COLOR_BGR2GRAY)
imgEdges=cv2.Canny(imgGray,100,250)
imgLines= cv2.HoughLinesP(imgEdges,2,np.pi/100,60, minLineLength = 10, maxLineGap = 100)
for x1,y1,x2,y2 in imgLines[0]:
    cv2.line(img,(x1,y1),(x2,y2),(0,255,0),2)

cv2.imshow('Final Image with dotted Lines detected',img) 

My output image is below. As you can see I only managed to detect the last dotted line. I have played around with the parameters rho,theta,min/max line but no luck.

Any advice is greatly appreciated :)

For the original link - which has the images 
https://stackoverflow.com/questions/61239652/detect-dotted-broken-lines-only-in-an-image-using-opencv