How to avoid the MinAreaRec plot for the whole canvas of window? - opencv

Question

So, I am trying to measure the line (check the attached code and result), the problem is when creating the boxplot points to measure the line it also creating boxplot points of the whole canvas of window no matter the image or thresholding value is. I also tried to limit in contourarea(c) command but couldn't limit it (don't know why). Kindly improvise the code or explain where I can counter this problem of mine in layman language as I am a newbee.
Thankyou!
import cv2
import numpy as np
import imutils
import imutils.perspective as persp
import scipy.spatial.distance as dist
print("PRESSED MODE 1 CONTOUR")
# cv2.destroyAllWindows()
img = cv2.imread('opencv_frame_3.png')
# img2 = cv2.imread('shapes.jpg')
# rgb_img2 = cv2.cvtColor(img, cv2.COLOR_BGR2RGB)
gray = cv2.cvtColor(img,cv2.COLOR_BGR2GRAY)
rgb_img = cv2.cvtColor(gray, cv2.COLOR_BGR2RGB)
# thresh, thresh_img = cv2.threshold(gray,90,255,cv2.THRESH_BINARY)
# thresh_img = cv2.erode(thresh_img, None, iterations=5)
# thresh_img = cv2.dilate(thresh_img, None, iterations=1)
# rgb_img_thresh = cv2.cvtColor(thresh_img, cv2.COLOR_BGR2RGB)
thresh_img = cv2.adaptiveThreshold(gray,255,cv2.ADAPTIVE_THRESH_GAUSSIAN_C,cv2.THRESH_BINARY,17,5)
# thresh_img = cv2.adaptiveThreshold(gray,255,cv2.ADAPTIVE_THRESH_MEAN_C,cv2.THRESH_BINARY,175,15)
# thr = cv2.cvtColor(thr, cv2.COLOR_BGR2RGB)
conts = cv2.findContours(thresh_img, cv2.RETR_TREE,cv2.CHAIN_APPROX_SIMPLE)
conts = imutils.grab_contours(conts)
# print(len(conts))
cont_img = np.zeros(img.shape)
cont_img = cv2.drawContours(cont_img,conts, -1 , (0,255,0),1)
cont_img2 = np.copy(img)
cont_img2 = cv2.drawContours(cont_img2,conts, -1 , (0,255,0),1)
# cv2.imshow('black',cont_img)
def midPoint (ptA, ptB):
return ((ptA[0]+ptB[0])/2 , (ptA[1]+ptB[1])/2)
for c in conts:
box = cv2.minAreaRect(c)
# print(box)
box = cv2.boxPoints(box)
box = np.array(box, dtype='int')
area = cv2.contourArea(c)
# print(area)
if cv2.contourArea(c) < 50000:
continue
area = cv2.contourArea(c)
print(area/96)
print("________")
cv2.drawContours(cont_img,[c],-1,(0,0,255),2)
cv2.drawContours(cont_img, [box], -1, (255, 0, 0), 2)
cv2.drawContours(cont_img2,[c],-1,(0,0,255),2)
cv2.drawContours(cont_img2, [box], -1, (255, 0, 0), 2)
for (x,y) in box:
cv2.circle(cont_img,(x,y),2,(255,255,255),20)
cv2.circle(cont_img2, (x, y), 2, (255, 255, 255), 20)
(tl,tr,br,bl) = box
(trX,tlX) = midPoint(tr,tl)
(brX, blX) = midPoint(br, bl)
cv2.circle(cont_img, (int(trX), int(tlX)),1, (0, 255, 255), 20)
cv2.circle(cont_img, (int(brX), int(blX)),1, (0, 255, 255), 20)
cv2.line(cont_img, (int(trX), int(tlX)), (int(brX), int(blX)), (255,0,255), 2)
cv2.circle(cont_img2, (int(trX), int(tlX)), 1, (0, 255, 255), 20)
cv2.circle(cont_img2, (int(brX), int(blX)), 1, (0, 255, 255), 20)
cv2.line(cont_img2, (int(trX), int(tlX)), (int(brX), int(blX)), (255, 0, 255), 2)
dA = dist.euclidean((int(trX), int(tlX)), (int(brX), int(blX)))
cv2.putText(cont_img,"{:.2f} px".format(dA/300), (int(trX+20), int(blX-20)),
cv2.FONT_HERSHEY_SIMPLEX,0.7,(0,255,255),2)
cv2.putText(cont_img2,"{:.2f} px".format(dA/300), (int(trX+20), int(blX-20)),
cv2.FONT_HERSHEY_SIMPLEX,0.7,(0,255,255),2)
(tlX, blX) = midPoint(tl, bl)
(trX, brX) = midPoint(tr, br)
cv2.circle(cont_img, (int(tlX), int(blX)),1, (0, 255, 0), 20)
cv2.circle(cont_img, (int(trX), int(brX)),1, (0, 255, 0), 20)
cv2.line(cont_img, (int(tlX), int(blX)), (int(trX), int(brX)), (255,0,255), 2)
cv2.circle(cont_img2, (int(tlX), int(blX)),1, (0, 255, 0), 20)
cv2.circle(cont_img2, (int(trX), int(brX)),1, (0, 255, 0), 20)
cv2.line(cont_img2, (int(tlX), int(blX)), (int(trX), int(brX)), (255,0,255), 2)
dB = dist.euclidean((int(tlX), int(blX)), (int(trX), int(brX)))
cv2.putText(cont_img,"{:.2f} in".format(dB/300), (int(trX-120), int(blX-320)),
cv2.FONT_HERSHEY_SIMPLEX,0.7,(0, 255, 255),2)
cv2.putText(cont_img2, "{:.2f} in".format(dB/300), (int(trX-120), int(blX -320)),
cv2.FONT_HERSHEY_SIMPLEX,0.7, (0, 255, 255),2)
print("Line A", "{:.2f} in".format(dA/96))
print("Line B", "{:.2f} in".format(dB/96))
print("**************")
# cont_img = cv2.resize(cont_img,(0,0),fx=0.5,fy=0.5)
cv2.imshow('area',cont_img)
# cont_img2 = cv2.resize(cont_img2,(0,0),fx=0.5,fy=0.5)
# cv2.imshow('ORG',cont_img2)
# thresh_img = cv2.resize(thresh_img,(0,0),fx=0.5,fy=0.5)
cv2.imshow("thresh", thresh_img)
# imgStack = stackImages(0.4,([img,rgb_img],
# [rgb_img_thresh,cont_img]))
#
# cv2.imshow('imgthresh',imgStack)
cv2.waitKey(0)
cv2.destroyAllWindows()
Check the image of output the whole window size is getting measured
I tried to either limit the measurement or area of contourarea(c) or c itself but it doesn't work for me