OpenCV3也提供了一些经常用于计算机视觉的实用功能，列举如下:
| 功能 | 描述 |
|---|---|
| cv::alignPtr() | Align pointer to given number of bytes 对齐指针到指定字节数 |
| cv::alignSize() | Align buffer size to given number of bytes 将缓存区大小与给定的字节数对齐 |
| cv::allocate() | Allocate a C-style array of objects 分配一个C风格的数组对象 |
| cvCeil() | Round float number x to nearest integer not smaller than x近似一个浮点数x到不小于x的最近的整数（向上取整） |
| cv::cubeRoot() | Compute the cube root of a number 计算一个数的立方根 |
| cv::CV_Assert() | Throw an exception if a given condition is not true 如果给定条件为假，则抛出异常 |
| CV_Error() | Macro to build a cv::Exception (from a fixed string) and throw it 构造cv::Exception（从固定的字符串）并抛出异常的一个宏 |
| CV_Error_() | Macro to build a cv::Exception (from a formatted string) and throw it 构造cv::Exception（从格式化的字符串）并抛出异常的一个宏 |
| cv::deallocate() | Deallocate a C-style array of objects 释放一个C风格的数组对象 |
| cv::error() | Indicate an error and throw an exception 指示错误并抛出异常 |
| cv::fastAtan2() | Calculate two-dimensional angle of a vector in degrees 向量的二维角度的计算，取值范围 [ 0.0, 360.0 ) |
| cv::fastFree() | Deallocate a memory buffer 释放一个内存缓存区 |
| cv::fastMalloc() | Allocate an aligned memory buffer 分配一个对齐的内存缓存区 |
| cvFloor() | Round float number x to nearest integer not larger than x 近似一个浮点数x到不大于x的最近的整数（向下取整） |
| cv::format() | Create an STL string using sprintf-like formatting 以sprintf类似格式创建一个STL字符串 |
| cv::getCPUTickCount() | Get tick count from internal CPU timer 从内部CPU计时器获得tick计数 |
| cv::getNumThreads() | Count number of threads currently used by OpenCV 获得当前OpenCV使用的线程数 |
| cv::getOptimalDFTSize() | Compute the best size for an array that you plan to pass to cv::DFT() 计算要传递给cv::DFT()的数组的最适宜大小 |
| cv::getThreadNum() | Get index of the current thread 获得当前线程的索引 |
| cv::getTickCount() | Get tick count from system 获得系统的tick计数 |
| cv::getTickFrequency() | Get number or ticks per second (see cv::getTickCount()) 获得每秒的tick计数 |
| cvIsInf() | Check if a floating-point number x is infinity 判断一个浮点数x是否无穷 |
| cvIsNaN() | Check if a floating-point number x is “Not a Number” 判断一个浮点数x是否不是一个数 |
| cvRound() | Round float number x to the nearest integer 近似一个浮点数x到最近的整数（四舍五入） |
| cv::setNumThreads() | Set number of threads used by OpenCV 设定OpenCV使用的线程数 |
| cv::setUseOptimized() | Enables or disables the use of optimized code (SSE2, etc.) 开启或关闭优化代码 (SSE2, etc.) |
| cv::useOptimized() | Indicates status of optimized code enabling 指示代码优化的启用 |
