**Description:**

I am working on solving rubiks cube using Python & OpenCV. For this purpose I am trying to extract all the colors of the cubies(individual cube pieces) and then applying appropriate algorithm(which I've designed, no issues there).

**The problem:**

Suppose if I've extracted all the colors of the cubies, how I can locate the position of the extracted cubies? How will I know whether it is in top-middle-lower layer or whether its a corner-middle-edge piece?

**What I've done:**

Here I have just extracted yellow color.

***After color extraction:***

![enter image description here](https://i.stack.imgur.com/x298k.jpg)

***Original Image***

![enter image description here](https://i.stack.imgur.com/OYFN2.png)

***The Code***

```
import numpy as np
import cv2
from cv2 import *

im = cv2.imread('v123.bmp')
im = cv2.bilateralFilter(im,9,75,75)
im = cv2.fastNlMeansDenoisingColored(im,None,10,10,7,21)
hsv_img = cv2.cvtColor(im, cv2.COLOR_BGR2HSV)   # HSV image

COLOR_MIN = np.array([20, 100, 100],np.uint8)       # HSV color code lower and upper bounds
COLOR_MAX = np.array([30, 255, 255],np.uint8)       # color yellow 

frame_threshed = cv2.inRange(hsv_img, COLOR_MIN, COLOR_MAX)     # Thresholding image
imgray = frame_threshed
ret,thresh = cv2.threshold(frame_threshed,127,255,0)
contours, hierarchy = cv2.findContours(thresh,cv2.RETR_TREE,cv2.CHAIN_APPROX_SIMPLE)
print type(contours)
for cnt in contours:
    x,y,w,h = cv2.boundingRect(cnt)
    print x,
    print y
    cv2.rectangle(im,(x,y),(x+w,y+h),(0,255,0),2)
cv2.imshow("Show",im)
cv2.imwrite("extracted.jpg", im)
cv2.waitKey()
cv2.destroyAllWindows()

```

Please give some suggestions on how can I locate the positions of the cubies. Here 4 yellow cubies are spotted: top-right-corner, center, right-edge, bottom-left-corner. How can I identify these positions for eg: by assigning digits to each position (here: 3, 4, 5, 7)

Any help/idea is appreciated :) Thanks.

P.S.: OpenCV newbie :)