kcv_normalAndNCHW

Usage

Performs normalization, the result of which is used as the input of deep learning models. It is optimized based on the user-defined normalAndNCHW interface.

Interface

int kcv_normalAndNCHW(
    cv::Mat &mat, const std::array<float, 3> &mean, const std::array<float, 3> &std, float *outBuf, int mode);

Parameters

Parameter	Description	Value Range	Input/Output
mat	Input image.	Not null, floating point, 3-channel	Input
mean	Mean value of each channel.	Floating point number less than 1	Input
std	Standard deviation of each channel.	Floating point number less than 1	Input
mode	Operation mode.	0: simple1 mode. The interface performs channel separation and saves the separated channels in a buffer. 1: simple2 mode. The interface performs the same operations as those in simple1 mode, but the buffer is allocated in advance in simple2 mode, delivering higher performance. 2: withMeanStd1 mode. The interface performs channel analysis and normalization. 3: withMeanStd2 mode. The interface performs the same operations as those in withMeanStd1 mode while delivering higher performance.	Input

Example

#include <gtest/gtest.h>
#include <opencv2/opencv.hpp>
#include <algorithm>
#include "KPCV/kcv.h"
TEST(normalAndNCHW, normal)
{
    Mat m_mat = src.clone();
    m_mat.convertTo(m_mat, CV_32F, 1.0 / 255);
    std::array<float, 3> mean = {0.25603, 0.29465, 0.3477};
    std::array<float, 3> std = {0.18766, 0.16251, 0.19558};
    int testTime = 100;
    cv::TickMeter tm;
    int img_h = m_mat.rows;
    int img_w = m_mat.cols;
    int hw = img_h * img_w;
    int pc = img_h * img_w * 3;
    std::vector<float> simple1_opencv(pc), simple2_opencv(pc),
        withMeanStd1_opencv(pc), withMeanStd2_opencv(pc);
    // simple1
    normalAndNCHW(m_mat, simple1_opencv.data(), 0);
    // simple2
    normalAndNCHW(m_mat, simple2_opencv.data(), 1);
    // withMeanStd1
    normalAndNCHW(m_mat, mean, std, withMeanStd1_opencv.data(), 2);
    // withMeanStd2
    normalAndNCHW(m_mat, mean, std, withMeanStd2_opencv.data(), 3);
}

Parent topic: Interface Definition