How to seed randn function opencv

c++, opencv, random, random-seed

Solution

You can set seed for OpenCV functions using using the following snippet:

cv::theRNG().state = seed;

There is a subtlety for multithreaded programs - OpenCV uses thread-local random number generators so you need (re)set seed from the same thread.

Problem

I want to seed randn function but I'm not able to do it. ``` srand(time(NULL)); Mat mymat = Mat::zeroes(1024,1024,CV_32F); randn(mymat,0,1); ``` Should it not give me random mat, named `mymat`, whose `mean = 0`, and `variance = 1`? However, it gives the same `mymat` in every run. Here is the link for randn which claims srand to work. I tried to give different numbers instead of time(NULL), but all have the same output randoms. I have checked the same thing from another machine, it gives the same output with the first machine. So seeding is not working. Thanks,

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