Python OpenCV for linuxcnc

Grotius
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8 years 4 weeks ago #118310 by Grotius

Python OpenCV for linuxcnc was created by Grotius

Hi,

I was wondering if someone had already made a application for linuxcnc with Python OpenCV?

The idea is to make a possible radius 2 or 3mm on inox or steel with separate milling device in the back of the new to develop machine.

So therefor i need a high resolution webcam that can see how the product contour is defined. Next is then to mill the product on the moving belt.

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cmorley
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8 years 4 weeks ago #118331 by cmorley

Replied by cmorley on topic Python OpenCV for linuxcnc

qtvcp uses opencv for webcam alignment of workpiece.
It does nothing fancy other then digital zoom.

IIRC Samco has played with opencv to move the machine to center of hole...

Chris M

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Grotius
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8 years 4 weeks ago #118357 by Grotius

Replied by Grotius on topic Python OpenCV for linuxcnc

Hi Chris,

I have installed a webcam software called : cheese on linux with terminal command : sudo apt-get install cheese
It's a very bad webcam, you can see at the picture that i took of a tv remote control pendant.

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Then in the cheese software you can do edge detection, then you got this :

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Very bad output.
In the end i got something in inkscape to produce g-code

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I will try to get a better webcam.

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Grotius
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8 years 4 weeks ago #118367 by Grotius

Replied by Grotius on topic Python OpenCV for linuxcnc

Hi Chris,

I did install opencv on the command line :

sudo apt-get install python-opencv
sudo apt-get install python-matplotlib

in the grotius gui i added in the top level :

Code:

#opencv section :
import cv2
import numpy as np
from matplotlib import pyplot as plt

And i made a testbutton in glade ;

Code:

def on_OpenCV_test_pressed(self, widget, data=None):
      #test code :

      img = cv2.imread('rose.jpg',0)
      edges = cv2.Canny(img,100,200)

      plt.subplot(121),plt.imshow(img,cmap = 'gray')
      plt.title('Original Image'), plt.xticks([]), plt.yticks([])
      plt.subplot(122),plt.imshow(edges,cmap = 'gray')
      plt.title('Edge Image'), plt.xticks([]), plt.yticks([])

      plt.show()

      print " OpenCV pressed "

The file i used for example was a rose.jpg file.
So openCV it altready working in the linuxcnc gui within short time.
I like this.

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My first test with openCV is based on this tutorial : opencv-python-tutroals.readthedocs.io/en..._canny/py_canny.html

For today i ended with : matplotlib.org/users/image_tutorial.html
I think the matplot library has more opportunities to picture position's usable for cnc machine's.
The picture has x and y coordinates.

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Tomorrow i make a clean github gui for this.

Update :

This line converts a bmp file into a dxf directly in linuxcnc :

Code:

def on_OpenCV_test_pressed(self, widget, data=None):
load =  subprocess.call(['/usr/bin/potrace', '-b', 'dxf', '/home/grotius/linuxcnc-external-reverse/configs/sim/grotius/stinkbug.bmp', '-o', '/home/grotius/linuxcnc-external-reverse/configs/sim/grotius/stinkbug.dxf'])

In the top of the python file :
import subprocess
from subprocess import call

The output picture of the dxf file in draftsight :

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This is nice to have. We go to the next step now.
This code is behind a user gui button and is ready in about 0.1 seconds.

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