How to select edge/ black lines in an image only?

[Swyzy]

I want to select edge line or black lines from the image and then remove all other details from the image. I only need black line for coloring page
Link of image :

https://ibb.co/Dzg0x3p

[rich2005]

Not going to be easy with that sort of image.

You can get this: https://i.imgur.com/wOJDoMw.jpg using the median blur filter Filters -> Blur -> Median Blur Settings as shown
Repeat the filter again using the same parameters : https://i.imgur.com/1rhpQoA.jpg Some of the noise gone.
Gives this: https://i.imgur.com/U1nsudc.png You will still need to do a bit of touch-up.

[Swyzy]

Thanks this will work . Rest I will do some tweaks
i am new to photoshopand gimp all this
One more thing
can you also tell me how to dark these outlines too? With some filter not manually ?

[Ofnuts]

After the median blur:

• Fuzzy select the background
  
• Select ➤ grow by one pixel
  
• Select ➤ shrink by one pixel  (you can try the same grow/shrink with 2px instead)
  
• Select ➤ Invert
  
• Adda layer, filled with white
  
• Bucket-fill selection with black
  

   

[denzjos]

This is how I did it : 
Filters / Noise Reduction (strenght 32)
Then Filters / G'Mic-Qt / Black & White / Engrave ( use this filter 2 times )
Result :