参考：BRIEF描述子原理、 python源码实现及基于opencv实现
#include<iostream>
#include<opencv2/opencv.hpp>
int PATCH_SIZE = 48;
int KERNEL_SIZE = 9;
int smoothedSum(const cv::Mat& sum, const cv::KeyPoint& pt, int y, int x, bool use_orientation, cv::Matx21f R)
{
const int HALF_KERNEL = KERNEL_SIZE / 2;
if (use_orientation)
{
int rx = (int)(((float)x) * R(1, 0) - ((float)y) * R(0, 0));
int ry = (int)(((float)x) * R(0, 0) + ((float)y) * R(1, 0));
if (rx > 24) rx = 24;
if (rx < -24) rx = -24;
if (ry > 24) ry = 24;
if (ry < -24) ry = -24;
x = rx; y = ry;
}
const int img_y = (int)(pt.pt.y + 0.5) + y;
const int img_x = (int)(pt.pt.x + 0.5) + x;
return sum.at<int>(img_y + HALF_KERNEL + 1, img_x + HALF_KERNEL + 1)
- sum.at<int>(img_y + HALF_KERNEL + 1, img_x - HALF_KERNEL)
- sum.at<int>(img_y - HALF_KERNEL, img_x + HALF_KERNEL + 1)
+ sum.at<int>(img_y - HALF_KERNEL, img_x - HALF_KERNEL);
}
void pixelTests32(cv::Mat sum, std::vector<cv::KeyPoint> keypoints, cv::Mat descriptors, bool use_orientation)
{
cv::Matx21f R;
for (size_t i = 0; i < keypoints.size(); ++i)
{
uchar* desc = descriptors.ptr(static_cast<int>(i));
cv::KeyPoint pt = keypoints[i];
if (use_orientation)
{
float angle = pt.angle;
angle *= (float)(CV_PI / 180.f);
R(0, 0) = sin(angle);
R(1, 0) = cos(angle);
}
#include "generated_32.i"
}
}
void my_brief_des(cv::Mat image, std::vector<cv::KeyPoint> keypoints, int bytes = 32, bool use_orientation = false)
{
cv::Mat sum;
cv::integral(image, sum, CV_32S);
cv::KeyPointsFilter::runByImageBorder(keypoints, image.size(), PATCH_SIZE / 2 + KERNEL_SIZE / 2);
cv::Mat descriptors;
descriptors.create((int)keypoints.size(), bytes, CV_8U);
descriptors.setTo(cv::Scalar::all(0));
pixelTests32(sum, keypoints, descriptors, use_orientation);
std::cout << descriptors << std::endl;
}
int main()
{
cv::Mat img = cv::imread("susan_input1.png", 0);
cv::Ptr<cv::FastFeatureDetector> fast = cv::FastFeatureDetector::create();
std::vector<cv::KeyPoint> keypoints;
fast->detect(img, keypoints);
my_brief_des(img, keypoints);
return 0;
}
其中generated_32.i来自OpenCV源码，内容如下：
// Code generated with '$ scripts/generate_code.py src/test_pairs.txt 32'
#define SMOOTHED(y,x) smoothedSum(sum, pt, y, x, use_orientation, R)
desc[0] = (uchar)(((SMOOTHED(-2, -1) < SMOOTHED(7, -1)) << 7) + ((SMOOTHED(-14, -1) < SMOOTHED(-3, 3)) << 6) + ((SMOOTHED(1, -2) < SMOOTHED(11, 2)) << 5) + ((SMOOTHED(1, 6) < SMOOTHED(-10, -7)) << 4) + ((SMOOTHED(13, 2) < SMOOTHED(-1, 0)) << 3) + ((SMOOTHED(-14, 5) < SMOOTHED(5, -3)) << 2) + ((SMOOTHED(-2, 8) < SMOOTHED(2, 4)) << 1) + ((SMOOTHED(-11, 8) < SMOOTHED(-15, 5)) << 0));
desc[1] = (uchar)(((SMOOTHED(-6, -23) < SMOOTHED(8, -9)) << 7) + ((SMOOTHED(-12, 6) < SMOOTHED(-10, 8)) << 6) + ((SMOOTHED(-3, -1) < SMOOTHED(8, 1)) << 5) + ((SMOOTHED(3, 6) < SMOOTHED(5, 6)) << 4) + ((SMOOTHED(-7, -6) < SMOOTHED(5, -5)) << 3) + ((SMOOTHED(22, -2) < SMOOTHED(-11, -8)) << 2) + ((SMOOTHED(14, 7) < SMOOTHED(8, 5)) << 1) + ((SMOOTHED(-1, 14) < SMOOTHED(-5, -14)) << 0));
desc[2] = (uchar)(((SMOOTHED(-14, 9) < SMOOTHED(2, 0)) << 7) + ((SMOOTHED(7, -3) < SMOOTHED(22, 6)) << 6) + ((SMOOTHED(-6, 6) < SMOOTHED(-8, -5)) << 5) + ((SMOOTHED(-5, 9) < SMOOTHED(7, -1)) << 4) + ((SMOOTHED(-3, -7) < SMOOTHED(-10, -18)) << 3) + ((SMOOTHED(4, -5) < SMOOTHED(0, 11)) << 2) + ((SMOOTHED(2, 3) < SMOOTHED(9, 10)) << 1) + ((SMOOTHED(-10, 3) < SMOOTHED(4, 9)) << 0));
desc[3] = (uchar)(((SMOOTHED(0, 12) < SMOOTHED(-3, 19)) << 7) + ((SMOOTHED(1, 15) < SMOOTHED(-11, -5)) << 6) + ((SMOOTHED(14, -1) < SMOOTHED(7, 8)) << 5) + ((SMOOTHED(7, -23) < SMOOTHED(-5, 5)) << 4) + ((SMOOTHED(0, -6) < SMOOTHED(-10, 17)) << 3) + ((SMOOTHED(13, -4) < SMOOTHED(-3, -4)) << 2) + ((SMOOTHED(-12, 1) < SMOOTHED(-12, 2)) << 1) + ((SMOOTHED(0, 8) < SMOOTHED(3, 22)) << 0));
desc[4] = (uchar)(((SMOOTHED(-13, 13) < SMOOTHED(3, -1)) << 7) + ((SMOOTHED(-16, 17) < SMOOTHED(6, 10)) << 6) + ((SMOOTHED(7, 15) < SMOOTHED(-5, 0)) << 5) + ((SMOOTHED(2, -12) < SMOOTHED(19, -2)) << 4) + ((SMOOTHED(3, -6) < SMOOTHED(-4, -15)) << 3) + ((SMOOTHED(8, 3) < SMOOTHED(0, 14)) << 2) + ((SMOOTHED(4, -11) < SMOOTHED(5, 5)) << 1) + ((SMOOTHED(11, -7) < SMOOTHED(7, 1)) << 0));
desc[5] = (uchar)(((SMOOTHED(6, 12) < SMOOTHED(21, 3)) << 7) + ((SMOOTHED(-3, 2) < SMOOTHED(14, 1)) << 6) + ((SMOOTHED(5, 1) < SMOOTHED(-5, 11)) << 5) + ((SMOOTHED(3, -17) < SMOOTHED(-6, 2)) << 4) + ((SMOOTHED(6, 8) < SMOOTHED(5, -10)) << 3) + ((SMOOTHED(-14, -2) < SMOOTHED(0, 4)) << 2) + ((SMOOTHED(5, -7) < SMOOTHED(-6, 5)) << 1) + ((SMOOTHED(10, 4) < SMOOTHED(4, -7)) << 0));
desc[6] = (uchar)(((SMOOTHED(22, 0) < SMOOTHED(7, -18)) << 7) + ((SMOOTHED(-1, -3) < SMOOTHED(0, 18)) << 6) + ((SMOOTHED(-4, 22) < SMOOTHED(-5, 3)) << 5) + ((SMOOTHED(1, -7) < SMOOTHED(2, -3)) << 4) + ((SMOOTHED(19, -20) < SMOOTHED(17, -2)) << 3) + ((SMOOTHED(3, -10) < SMOOTHED(-8, 24)) << 2) + ((SMOOTHED(-5, -14) < SMOOTHED(7, 5)) << 1) + ((SMOOTHED(-2, 12) < SMOOTHED(-4, -15)) << 0));
desc[7] = (uchar)(((SMOOTHED(4, 12) < SMOOTHED(0, -19)) << 7) + ((SMOOTHED(20, 13) < SMOOTHED(3, 5)) << 6) + ((SMOOTHED(-8, -12) < SMOOTHED(5, 0)) << 5) + ((SMOOTHED(-5, 6) < SMOOTHED(-7, -11)) << 4) + ((SMOOTHED(6, -11) < SMOOTHED(-3, -22)) << 3) + ((SMOOTHED(15, 4) < SMOOTHED(10, 1)) << 2) + ((SMOOTHED(-7, -4) < SMOOTHED(15, -6)) << 1) + ((SMOOTHED(5, 10) < SMOOTHED(0, 24)) << 0));
desc[8] = (uchar)(((SMOOTHED(3, 6) < SMOOTHED(22, -2)) << 7) + ((SMOOTHED(-13, 14) < SMOOTHED(4, -4)) << 6) + ((SMOOTHED(-13, 8) < SMOOTHED(-18, -22)) << 5) + ((SMOOTHED(-1, -1) < SMOOTHED(-7, 3)) << 4) + ((SMOOTHED(-19, -12) < SMOOTHED(4, 3)) << 3) + ((SMOOTHED(8, 10) < SMOOTHED(13, -2)) << 2) + ((SMOOTHED(-6, -1) < SMOOTHED(-6, -5)) << 1) + ((SMOOTHED(2, -21) < SMOOTHED(-3, 2)) << 0));
desc[9] = (uchar)(((SMOOTHED(4, -7) < SMOOTHED(0, 16)) << 7) + ((SMOOTHED(-6, -5) < SMOOTHED(-12, -1)) << 6) + ((SMOOTHED(1, -1) < SMOOTHED(9, 18)) << 5) + ((SMOOTHED(-7, 10) < SMOOTHED(-11, 6)) << 4) + ((SMOOTHED(4, 3) < SMOOTHED(19, -7)) << 3) + ((SMOOTHED(-18, 5) < SMOOTHED(-4, 5)) << 2) + ((SMOOTHED(4, 0) < SMOOTHED(-20, 4)) << 1) + ((SMOOTHED(7, -11) < SMOOTHED(18, 12)) << 0));
desc[10] = (uchar)(((SMOOTHED(-20, 17) < SMOOTHED(-18, 7)) << 7) + ((SMOOTHED(2, 15) < SMOOTHED(19, -11)) << 6) + ((SMOOTHED(-18, 6) < SMOOTHED(-7, 3)) << 5) + ((SMOOTHED(-4, 1) < SMOOTHED(-14, 13)) << 4) + ((SMOOTHED(17, 3) < SMOOTHED(2, -8)) << 3) + ((SMOOTHED(-7, 2) < SMOOTHED(1, 6)) << 2) + ((SMOOTHED(17, -9) < SMOOTHED(-2, 8)) << 1) + ((SMOOTHED(-8, -6) < SMOOTHED(-1, 12)) << 0));
desc[11] = (uchar)(((SMOOTHED(-2, 4) < SMOOTHED(-1, 6)) << 7) + ((SMOOTHED(-2, 7) < SMOOTHED(6, 8)) << 6) + ((SMOOTHED(-8, -1) < SMOOTHED(-7, -9)) << 5) + ((SMOOTHED(8, -9) < SMOOTHED(15, 0)) << 4) + ((SMOOTHED(0, 22) < SMOOTHED(-4, -15)) << 3) + ((SMOOTHED(-14, -1) < SMOOTHED(3, -2)) << 2) + ((SMOOTHED(-7, -4) < SMOOTHED(17, -7)) << 1) + ((SMOOTHED(-8, -2) < SMOOTHED(9, -4)) << 0));
desc[12] = (uchar)(((SMOOTHED(5, -7) < SMOOTHED(7, 7)) << 7) + ((SMOOTHED(-5, 13) < SMOOTHED(-8, 11)) << 6) + ((SMOOTHED(11, -4) < SMOOTHED(0, 8)) << 5) + ((SMOOTHED(5, -11) < SMOOTHED(-9, -6)) << 4) + ((SMOOTHED(2, -6) < SMOOTHED(3, -20)) << 3) + ((SMOOTHED(-6, 2) < SMOOTHED(6, 10)) << 2) + ((SMOOTHED(-6, -6) < SMOOTHED(-15, 7)) << 1) + ((SMOOTHED(-6, -3) < SMOOTHED(2, 1)) << 0));
desc[13] = (uchar)(((SMOOTHED(11, 0) < SMOOTHED(-3, 2)) << 7) + ((SMOOTHED(7, -12) < SMOOTHED(14, 5)) << 6) + ((SMOOTHED(0, -7) < SMOOTHED(-1, -1)) << 5) + ((SMOOTHED(-16, 0) < SMOOTHED(6, 8)) << 4) + ((SMOOTHED(22, 11) < SMOOTHED(0, -3)) << 3) + ((SMOOTHED(19, 0) < SMOOTHED(5, -17)) << 2) + ((SMOOTHED(-23, -14) < SMOOTHED(-13, -19)) << 1) + ((SMOOTHED(-8, 10) < SMOOTHED(-11, -2)) << 0));
desc[14] = (uchar)(((SMOOTHED(-11, 6) < SMOOTHED(-10, 13)) << 7) + ((SMOOTHED(1, -7) < SMOOTHED(14, 0)) << 6) + ((SMOOTHED(-12, 1) < SMOOTHED(-5, -5)) << 5) + ((SMOOTHED(4, 7) < SMOOTHED(8, -1)) << 4) + ((SMOOTHED(-1, -5) < SMOOTHED(15, 2)) << 3) + ((SMOOTHED(-3, -1) < SMOOTHED(7, -10)) << 2) + ((SMOOTHED(3, -6) < SMOOTHED(10, -18)) << 1) + ((SMOOTHED(-7, -13) < SMOOTHED(-13, 10)) << 0));
desc[15] = (uchar)(((SMOOTHED(1, -1) < SMOOTHED(13, -10)) << 7) + ((SMOOTHED(-19, 14) < SMOOTHED(8, -14)) << 6) + ((SMOOTHED(-4, -13) < SMOOTHED(7, 1)) << 5) + ((SMOOTHED(1, -2) < SMOOTHED(12, -7)) << 4) + ((SMOOTHED(3, -5) < SMOOTHED(1, -5)) << 3) + ((SMOOTHED(-2, -2) < SMOOTHED(8, -10)) << 2) + ((SMOOTHED(2, 14) < SMOOTHED(8, 7)) << 1) + ((SMOOTHED(3, 9) < SMOOTHED(8, 2)) << 0));
desc[16] = (uchar)(((SMOOTHED(-9, 1) < SMOOTHED(-18, 0)) << 7) + ((SMOOTHED(4, 0) < SMOOTHED(1, 12)) << 6) + ((SMOOTHED(0, 9) < SMOOTHED(-14, -10)) << 5) + ((SMOOTHED(-13, -9) < SMOOTHED(-2, 6)) << 4) + ((SMOOTHED(1, 5) < SMOOTHED(10, 10)) << 3) + ((SMOOTHED(-3, -6) < SMOOTHED(-16, -5)) << 2) + ((SMOOTHED(11, 6) < SMOOTHED(-5, 0)) << 1) + ((SMOOTHED(-23, 10) < SMOOTHED(1, 2)) << 0));
desc[17] = (uchar)(((SMOOTHED(13, -5) < SMOOTHED(-3, 9)) << 7) + ((SMOOTHED(-4, -1) < SMOOTHED(-13, -5)) << 6) + ((SMOOTHED(10, 13) < SMOOTHED(-11, 8)) << 5) + ((SMOOTHED(19, 20) < SMOOTHED(-9, 2)) << 4) + ((SMOOTHED(4, -8) < SMOOTHED(0, -9)) << 3) + ((SMOOTHED(-14, 10) < SMOOTHED(15, 19)) << 2) + ((SMOOTHED(-14, -12) < SMOOTHED(-10, -3)) << 1) + ((SMOOTHED(-23, -3) < SMOOTHED(17, -2)) << 0));
desc[18] = (uchar)(((SMOOTHED(-3, -11) < SMOOTHED(6, -14)) << 7) + ((SMOOTHED(19, -2) < SMOOTHED(-4, 2)) << 6) + ((SMOOTHED(-5, 5) < SMOOTHED(3, -13)) << 5) + ((SMOOTHED(2, -2) < SMOOTHED(-5, 4)) << 4) + ((SMOOTHED(17, 4) < SMOOTHED(17, -11)) << 3) + ((SMOOTHED(-7, -2) < SMOOTHED(1, 23)) << 2) + ((SMOOTHED(8, 13) < SMOOTHED(1, -16)) << 1) + ((SMOOTHED(-13, -5) < SMOOTHED(1, -17)) << 0));
desc[19] = (uchar)(((SMOOTHED(4, 6) < SMOOTHED(-8, -3)) << 7) + ((SMOOTHED(-5, -9) < SMOOTHED(-2, -10)) << 6) + ((SMOOTHED(-9, 0) < SMOOTHED(-7, -2)) << 5) + ((SMOOTHED(5, 0) < SMOOTHED(5, 2)) << 4) + ((SMOOTHED(-4, -16) < SMOOTHED(6, 3)) << 3) + ((SMOOTHED(2, -15) < SMOOTHED(-2, 12)) << 2) + ((SMOOTHED(4, -1) < SMOOTHED(6, 2)) << 1) + ((SMOOTHED(1, 1) < SMOOTHED(-2, -8)) << 0));
desc[20] = (uchar)(((SMOOTHED(-2, 12) < SMOOTHED(-5, -2)) << 7) + ((SMOOTHED(-8, 8) < SMOOTHED(-9, 9)) << 6) + ((SMOOTHED(2, -10) < SMOOTHED(3, 1)) << 5) + ((SMOOTHED(-4, 10) < SMOOTHED(-9, 4)) << 4) + ((SMOOTHED(6, 12) < SMOOTHED(2, 5)) << 3) + ((SMOOTHED(-3, -8) < SMOOTHED(0, 5)) << 2) + ((SMOOTHED(-13, 1) < SMOOTHED(-7, 2)) << 1) + ((SMOOTHED(-1, -10) < SMOOTHED(7, -18)) << 0));
desc[21] = (uchar)(((SMOOTHED(-1, 8) < SMOOTHED(-9, -10)) << 7) + ((SMOOTHED(-23, -1) < SMOOTHED(6, 2)) << 6) + ((SMOOTHED(-5, -3) < SMOOTHED(3, 2)) << 5) + ((SMOOTHED(0, 11) < SMOOTHED(-4, -7)) << 4) + ((SMOOTHED(15, 2) < SMOOTHED(-10, -3)) << 3) + ((SMOOTHED(-20, -8) < SMOOTHED(-13, 3)) << 2) + ((SMOOTHED(-19, -12) < SMOOTHED(5, -11)) << 1) + ((SMOOTHED(-17, -13) < SMOOTHED(-3, 2)) << 0));
desc[22] = (uchar)(((SMOOTHED(7, 4) < SMOOTHED(-12, 0)) << 7) + ((SMOOTHED(5, -1) < SMOOTHED(-14, -6)) << 6) + ((SMOOTHED(-4, 11) < SMOOTHED(0, -4)) << 5) + ((SMOOTHED(3, 10) < SMOOTHED(7, -3)) << 4) + ((SMOOTHED(13, 21) < SMOOTHED(-11, 6)) << 3) + ((SMOOTHED(-12, 24) < SMOOTHED(-7, -4)) << 2) + ((SMOOTHED(4, 16) < SMOOTHED(3, -14)) << 1) + ((SMOOTHED(-3, 5) < SMOOTHED(-7, -12)) << 0));
desc[23] = (uchar)(((SMOOTHED(0, -4) < SMOOTHED(7, -5)) << 7) + ((SMOOTHED(-17, -9) < SMOOTHED(13, -7)) << 6) + ((SMOOTHED(22, -6) < SMOOTHED(-11, 5)) << 5) + ((SMOOTHED(2, -8) < SMOOTHED(23, -11)) << 4) + ((SMOOTHED(7, -10) < SMOOTHED(-1, 14)) << 3) + ((SMOOTHED(-3, -10) < SMOOTHED(8, 3)) << 2) + ((SMOOTHED(-13, 1) < SMOOTHED(-6, 0)) << 1) + ((SMOOTHED(-7, -21) < SMOOTHED(6, -14)) << 0));
desc[24] = (uchar)(((SMOOTHED(18, 19) < SMOOTHED(-4, -6)) << 7) + ((SMOOTHED(10, 7) < SMOOTHED(-1, -4)) << 6) + ((SMOOTHED(-1, 21) < SMOOTHED(1, -5)) << 5) + ((SMOOTHED(-10, 6) < SMOOTHED(-11, -2)) << 4) + ((SMOOTHED(18, -3) < SMOOTHED(-1, 7)) << 3) + ((SMOOTHED(-3, -9) < SMOOTHED(-5, 10)) << 2) + ((SMOOTHED(-13, 14) < SMOOTHED(17, -3)) << 1) + ((SMOOTHED(11, -19) < SMOOTHED(-1, -18)) << 0));
desc[25] = (uchar)(((SMOOTHED(8, -2) < SMOOTHED(-18, -23)) << 7) + ((SMOOTHED(0, -5) < SMOOTHED(-2, -9)) << 6) + ((SMOOTHED(-4, -11) < SMOOTHED(2, -8)) << 5) + ((SMOOTHED(14, 6) < SMOOTHED(-3, -6)) << 4) + ((SMOOTHED(-3, 0) < SMOOTHED(-15, 0)) << 3) + ((SMOOTHED(-9, 4) < SMOOTHED(-15, -9)) << 2) + ((SMOOTHED(-1, 11) < SMOOTHED(3, 11)) << 1) + ((SMOOTHED(-10, -16) < SMOOTHED(-7, 7)) << 0));
desc[26] = (uchar)(((SMOOTHED(-2, -10) < SMOOTHED(-10, -2)) << 7) + ((SMOOTHED(-5, -3) < SMOOTHED(5, -23)) << 6) + ((SMOOTHED(13, -8) < SMOOTHED(-15, -11)) << 5) + ((SMOOTHED(-15, 11) < SMOOTHED(6, -6)) << 4) + ((SMOOTHED(-16, -3) < SMOOTHED(-2, 2)) << 3) + ((SMOOTHED(6, 12) < SMOOTHED(-16, 24)) << 2) + ((SMOOTHED(-10, 0) < SMOOTHED(8, 11)) << 1) + ((SMOOTHED(-7, 7) < SMOOTHED(-19, -7)) << 0));
desc[27] = (uchar)(((SMOOTHED(5, 16) < SMOOTHED(9, -3)) << 7) + ((SMOOTHED(9, 7) < SMOOTHED(-7, -16)) << 6) + ((SMOOTHED(3, 2) < SMOOTHED(-10, 9)) << 5) + ((SMOOTHED(21, 1) < SMOOTHED(8, 7)) << 4) + ((SMOOTHED(7, 0) < SMOOTHED(1, 17)) << 3) + ((SMOOTHED(-8, 12) < SMOOTHED(9, 6)) << 2) + ((SMOOTHED(11, -7) < SMOOTHED(-8, -6)) << 1) + ((SMOOTHED(19, 0) < SMOOTHED(9, 3)) << 0));
desc[28] = (uchar)(((SMOOTHED(1, -7) < SMOOTHED(-5, -11)) << 7) + ((SMOOTHED(0, 8) < SMOOTHED(-2, 14)) << 6) + ((SMOOTHED(12, -2) < SMOOTHED(-15, -6)) << 5) + ((SMOOTHED(4, 12) < SMOOTHED(0, -21)) << 4) + ((SMOOTHED(17, -4) < SMOOTHED(-6, -7)) << 3) + ((SMOOTHED(-10, -9) < SMOOTHED(-14, -7)) << 2) + ((SMOOTHED(-15, -10) < SMOOTHED(-15, -14)) << 1) + ((SMOOTHED(-7, -5) < SMOOTHED(5, -12)) << 0));
desc[29] = (uchar)(((SMOOTHED(-4, 0) < SMOOTHED(15, -4)) << 7) + ((SMOOTHED(5, 2) < SMOOTHED(-6, -23)) << 6) + ((SMOOTHED(-4, -21) < SMOOTHED(-6, 4)) << 5) + ((SMOOTHED(-10, 5) < SMOOTHED(-15, 6)) << 4) + ((SMOOTHED(4, -3) < SMOOTHED(-1, 5)) << 3) + ((SMOOTHED(-4, 19) < SMOOTHED(-23, -4)) << 2) + ((SMOOTHED(-4, 17) < SMOOTHED(13, -11)) << 1) + ((SMOOTHED(1, 12) < SMOOTHED(4, -14)) << 0));
desc[30] = (uchar)(((SMOOTHED(-11, -6) < SMOOTHED(-20, 10)) << 7) + ((SMOOTHED(4, 5) < SMOOTHED(3, 20)) << 6) + ((SMOOTHED(-8, -20) < SMOOTHED(3, 1)) << 5) + ((SMOOTHED(-19, 9) < SMOOTHED(9, -3)) << 4) + ((SMOOTHED(18, 15) < SMOOTHED(11, -4)) << 3) + ((SMOOTHED(12, 16) < SMOOTHED(8, 7)) << 2) + ((SMOOTHED(-14, -8) < SMOOTHED(-3, 9)) << 1) + ((SMOOTHED(-6, 0) < SMOOTHED(2, -4)) << 0));
desc[31] = (uchar)(((SMOOTHED(1, -10) < SMOOTHED(-1, 2)) << 7) + ((SMOOTHED(8, -7) < SMOOTHED(-6, 18)) << 6) + ((SMOOTHED(9, 12) < SMOOTHED(-7, -23)) << 5) + ((SMOOTHED(8, -6) < SMOOTHED(5, 2)) << 4) + ((SMOOTHED(-9, 6) < SMOOTHED(-12, -7)) << 3) + ((SMOOTHED(-1, -2) < SMOOTHED(-7, 2)) << 2) + ((SMOOTHED(9, 9) < SMOOTHED(7, 15)) << 1) + ((SMOOTHED(6, 2) < SMOOTHED(-6, 6)) << 0));
#undef SMOOTHED