Learning OpenCV, 2nd Edition

you could use your own instead) and using RNG::operator T() to get your random numbers (more on

that operator follows).

cv::RNG()

cv::RNG::RNG( void );

cv::RNG::RNG( uint64 state ); // create using the seed ‘state’

You can create an RNG object with either the default constructor, or you can pass it a 64-bit unsigned

integer that it will use as the seed of the random number sequence. If you call the default constructor (or

pass 0 to the second variation) the generator will initialize with a standardized value.

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cv::RNG::operator T()

cv::RNG::operator uchar();

cv::RNG::operator schar();

cv::RNG::operator ushort();

cv::RNG::operator short int();

cv::RNG::operator int();

cv::RNG::operator unsigned();

cv::RNG::operator float();

cv::RNG::operator double();

This is really a set of different methods that return a new random number from cv::RNG of some specific

type. Each of these is an overloaded cast operator, so in effect you cast the RNG object to whatever type

you want:

Example 3-2: Using the default random number generator we generate a pair of integers and a pair of

floating-point numbers; the style of the cast operation is up to you, this example shows both the int(x)

and the (int)x forms

cv::RNG rng = cv::theRNG();

cout << ”An integer: “ << (int)rng << endl;

cout << ”Another integer: “ << int(rng) << endl;

cout << ”A float: “ << (float)rng << endl;

cout <<