Memory leak in opencv 2.x

Question

I'm running a python script and it is giving insufficient memory error. I tried executing this script with both 2.4.9 and 2.4.11 and got the error. Is there any issue with these 2 versions of opencv?

---

import numpy as np
import cv2

MIN_MATCH_COUNT = 10

img1 = cv2.imread('./DSC_0022.jpg',0)          # queryImage
img2 = cv2.imread('./template.jpg',0) # trainImage

# Initiate SIFT detector
sift = cv2.SIFT()

# find the keypoints and descriptors with SIFT
kp1, des1 = sift.detectAndCompute(img1,None)
kp2, des2 = sift.detectAndCompute(img2,None)

FLANN_INDEX_KDTREE = 0
index_params = dict(algorithm = FLANN_INDEX_KDTREE, trees = 5)
search_params = dict(checks = 50)

flann = cv2.FlannBasedMatcher(index_params, search_params)

matches = flann.knnMatch(des1,des2,k=2)

# store all the good matches as per Lowe's ratio test.
good = []
for m,n in matches:
if m.distance < 0.7*n.distance:
    good.append(m)

if len(good)>MIN_MATCH_COUNT:
   src_pts = np.float32([ kp1[m.queryIdx].pt for m in good ]).reshape(-1,1,2)
   dst_pts = np.float32([ kp2[m.trainIdx].pt for m in good ]).reshape(-1,1,2)

   M, mask = cv2.findHomography(src_pts, dst_pts, cv2.RANSAC,5.0)
   matchesMask = mask.ravel().tolist()

   h,w = img1.shape
   pts = np.float32([ [0,0],[0,h-1],[w-1,h-1],[w-1,0] ]).reshape(-1,1,2)
   dst = cv2.perspectiveTransform(pts,M)

   img2 = cv2.polylines(img2,[np.int32(dst)],True,255,3, cv2.LINE_AA)

else:
   print "Not enough matches are found - %d/%d" % (len(good),MIN_MATCH_COUNT)
   matchesMask = None

---

Insufficient Memory Error:

C:\>fe.py
OpenCV Error: Insufficient memory (Failed to allocate 139253572 bytes) in cv::OutOfMemoryError, file ..\..\..\..\opencv\modules\core\src\alloc.cpp, line 52
Traceback (most recent call last):
File "C:\fe.py", line 15, in <module>
    kp2, des2 = sift.detectAndCompute(img2,None)
cv2.error: ..\..\..\..\opencv\modules\core\src\alloc.cpp:52: error: (-4) Failed to allocate 139253572 bytes in function cv::OutOfMemoryError

Answer 1

I was also getting the same error when I was trying to run a python script that was using OpenCV. My error was caused because there was no free memory left for the program and thus allocation of arrays wasn't possible - hence triggering the error.

Try seeing for what the memory is being used after running the python script and try optimizing the code so that RAM usage is reduced.