Opencv unable to get ROI of highest intensity part

I have tried this code.

import sys
import numpy as np
sys.path.append('/usr/local/lib/python2.7/site-packages')
import cv2
from cv2.cv import *
img=cv2.imread("test2.jpg",cv2.IMREAD_COLOR)
gimg = cv2.imread("test2.jpg",cv2.IMREAD_GRAYSCALE)
b,g,r = cv2.split(img)
ret,thresh1 = cv2.threshold(gimg,127,255,cv2.THRESH_BINARY);
numrows = len(thresh1)    
numcols = len(thresh1[0])
thresh = 170
im_bw = cv2.threshold(gimg, thresh, 255, cv2.THRESH_BINARY)[1]
trig=0
trigmax=0;
xmax=0
ymax=0
for x in range(0,numrows):
for y in range(0,numcols):
    if(im_bw[x][y]==1):
        trig=trig+1;
if(trig>5):
    xmax=x;
    ymax=y;
    break;
print x,y,numrows,numcols,trig
roi=gimg[xmax:xmax+200,ymax-500:ymax]
cv2.imshow("roi",roi)
WaitKey(0)

here test2.jpg is what I am tring to do is to concentrate on the high intensity part of the image(i.e the circle with high intensity in image).But my code does not seem to do so. Can anyone help?

I found answer to my question from here

here is my code

# import the necessary packages
  import numpy as np
  import cv2
# load the image and convert it to grayscale
 image = cv2.imread('test2.jpg')
 orig = image.copy()
 gray = cv2.cvtColor(image, cv2.COLOR_BGR2GRAY)
# apply a Gaussian blur to the image then find the brightest
# region
gray = cv2.GaussianBlur(gray, (41, 41), 0)
(minVal, maxVal, minLoc, maxLoc) = cv2.minMaxLoc(gray)
image = orig.copy()
roi=image[maxLoc[1]-250:maxLoc[1]+250,maxLoc[0]-250:maxLoc[0]+250,2:2] 
cv2.imshow("Robust", roi)
cv2.waitKey(0)

test2.jpg

ROI