Learning OpenCV, 2nd Edition

cvIsInf()

41

Check if a floating-point number x is infinity

cvIsNaN()

41

Check if a floating-point number x is “Not a Number”

cvRound()

Round float number x to the nearest integer

cv::setNumThreads()

Set number of threads used by OpenCV

cv::setUseOptimized()

Enables or disables the use of optimized code (SSE2, etc.)

cv::useOptimized()

Indicates status of optimized code enabling (see

cv::setUseOptimized())

cv::alignPtr()

template<T> T* cv::alignPtr( // Return aligned pointer of type T*

T* ptr, // pointer, unaligned

int n = sizeof(T) // align to block size, a power of 2

);

Given a pointer of any type, this function computes an aligned pointer of the same type according to the

following computation:

(T*)(((size_t)ptr + n+1) & -n)

On some architectures, it is not even possible to read a multi-byte object from an address

that is not evenly divisible by the size of the object (i.e.,.,, by 4 for a 32-bit integer). On

architectures such as x86, this is handled for you automatically by the CPU by using

multiple reads and assembling your value from those reads at the cost of a substantial

penalty in performance.

cv::alignSize()

size_t cv::alignSize( // minimum size >=’sz’ divisible by ‘n’

size_t sz, // size of buffer

int n = sizeof(T) // align to block size, a power of 2

);

Given a number n (typically a return value from sizeof()), and a size ...