Detecting Blue Color in this image

edit

This image was taken from a Quad-Copter. I need to detect the blue color that the guy in this picture is wearing.

It would be very helpful if you guys would try to guide me. I am also attaching the code that i used. The hsv range never seems to be correct.

import cv2
import numpy as np
from matplotlib import pyplot as plt

frame = cv2.imread("a.jpeg")
img = frame
hsv = cv2.cvtColor(img,cv2.COLOR_BGR2HSV)
lower_blue= np.array([78,158,124])
upper_blue = np.array([138,255,255])

mask = cv2.inRange(img,lower_blue,upper_blue)

img,cnts,hie = cv2.findContours(mask,cv2.RETR_TREE,cv2.CHAIN_APPROX_NONE)
cv2.drawContours(frame,cnts,-1,(0,255,0),3)

cv2.imshow("Frame",frame)
cv2.waitKey(0)