diff --git a/modules/xfeatures2d/include/opencv2/xfeatures2d.hpp b/modules/xfeatures2d/include/opencv2/xfeatures2d.hpp index a194c9662..9d0d2e5ec 100644 --- a/modules/xfeatures2d/include/opencv2/xfeatures2d.hpp +++ b/modules/xfeatures2d/include/opencv2/xfeatures2d.hpp @@ -259,6 +259,32 @@ public: }; + +/** @brief Estimates cornerness for prespecified KeyPoints using the FAST algorithm + +@param image grayscale image where keypoints (corners) are detected. +@param keypoints keypoints which should be tested to fit the FAST criteria. Keypoints not beeing +detected as corners are removed. +@param threshold threshold on difference between intensity of the central pixel and pixels of a +circle around this pixel. +@param nonmaxSuppression if true, non-maximum suppression is applied to detected corners +(keypoints). +@param type one of the three neighborhoods as defined in the paper: +FastFeatureDetector::TYPE_9_16, FastFeatureDetector::TYPE_7_12, +FastFeatureDetector::TYPE_5_8 + +Detects corners using the FAST algorithm by @cite Rosten06 . + */ +CV_EXPORTS void FASTForPointSet( InputArray image, CV_IN_OUT std::vector& keypoints, + int threshold, bool nonmaxSuppression=true, int type=FastFeatureDetector::TYPE_9_16); + + +void makeOffsets(int pixel[25], int row_stride, int patternSize); + +template +int cornerScore(const uchar* ptr, const int pixel[], int threshold); + + //! @} } diff --git a/modules/xfeatures2d/src/fast.cpp b/modules/xfeatures2d/src/fast.cpp new file mode 100644 index 000000000..0699a3b38 --- /dev/null +++ b/modules/xfeatures2d/src/fast.cpp @@ -0,0 +1,513 @@ +/*M/////////////////////////////////////////////////////////////////////////////////////// +// +// IMPORTANT: READ BEFORE DOWNLOADING, COPYING, INSTALLING OR USING. +// +// By downloading, copying, installing or using the software you agree to this license. +// If you do not agree to this license, do not download, install, +// copy or use the software. +// +// +// License Agreement +// For Open Source Computer Vision Library +// +// Copyright (C) 2000-2008, Intel Corporation, all rights reserved. +// Copyright (C) 2009, Willow Garage Inc., all rights reserved. +// Third party copyrights are property of their respective owners. +// +// Redistribution and use in source and binary forms, with or without modification, +// are permitted provided that the following conditions are met: +// +// * Redistribution's of source code must retain the above copyright notice, +// this list of conditions and the following disclaimer. +// +// * Redistribution's in binary form must reproduce the above copyright notice, +// this list of conditions and the following disclaimer in the documentation +// and/or other materials provided with the distribution. +// +// * The name of the copyright holders may not be used to endorse or promote products +// derived from this software without specific prior written permission. +// +// This software is provided by the copyright holders and contributors "as is" and +// any express or implied warranties, including, but not limited to, the implied +// warranties of merchantability and fitness for a particular purpose are disclaimed. +// In no event shall the Intel Corporation or contributors be liable for any direct, +// indirect, incidental, special, exemplary, or consequential damages +// (including, but not limited to, procurement of substitute goods or services; +// loss of use, data, or profits; or business interruption) however caused +// and on any theory of liability, whether in contract, strict liability, +// or tort (including negligence or otherwise) arising in any way out of +// the use of this software, even if advised of the possibility of such damage. +// +//M*/ + +#include + +#ifndef VERIFY_CORNERS +#define VERIFY_CORNERS 0 +#endif + +namespace cv { + namespace xfeatures2d { + + + #if VERIFY_CORNERS + static void testCorner(const uchar* ptr, const int pixel[], int K, int N, int threshold) { + // check that with the computed "threshold" the pixel is still a corner + // and that with the increased-by-1 "threshold" the pixel is not a corner anymore + for( int delta = 0; delta <= 1; delta++ ) + { + int v0 = std::min(ptr[0] + threshold + delta, 255); + int v1 = std::max(ptr[0] - threshold - delta, 0); + int c0 = 0, c1 = 0; + + for( int k = 0; k < N; k++ ) + { + int x = ptr[pixel[k]]; + if(x > v0) + { + if( ++c0 > K ) + break; + c1 = 0; + } + else if( x < v1 ) + { + if( ++c1 > K ) + break; + c0 = 0; + } + else + { + c0 = c1 = 0; + } + } + CV_Assert( (delta == 0 && std::max(c0, c1) > K) || + (delta == 1 && std::max(c0, c1) <= K) ); + } + } + #endif + + template<> + int cornerScore<16>(const uchar* ptr, const int pixel[], int threshold) + { + const int K = 8, N = K*3 + 1; + int k, v = ptr[0]; + short d[N]; + for( k = 0; k < N; k++ ) + d[k] = (short)(v - ptr[pixel[k]]); + + #if CV_SSE2 + __m128i q0 = _mm_set1_epi16(-1000), q1 = _mm_set1_epi16(1000); + for( k = 0; k < 16; k += 8 ) + { + __m128i v0 = _mm_loadu_si128((__m128i*)(d+k+1)); + __m128i v1 = _mm_loadu_si128((__m128i*)(d+k+2)); + __m128i a = _mm_min_epi16(v0, v1); + __m128i b = _mm_max_epi16(v0, v1); + v0 = _mm_loadu_si128((__m128i*)(d+k+3)); + a = _mm_min_epi16(a, v0); + b = _mm_max_epi16(b, v0); + v0 = _mm_loadu_si128((__m128i*)(d+k+4)); + a = _mm_min_epi16(a, v0); + b = _mm_max_epi16(b, v0); + v0 = _mm_loadu_si128((__m128i*)(d+k+5)); + a = _mm_min_epi16(a, v0); + b = _mm_max_epi16(b, v0); + v0 = _mm_loadu_si128((__m128i*)(d+k+6)); + a = _mm_min_epi16(a, v0); + b = _mm_max_epi16(b, v0); + v0 = _mm_loadu_si128((__m128i*)(d+k+7)); + a = _mm_min_epi16(a, v0); + b = _mm_max_epi16(b, v0); + v0 = _mm_loadu_si128((__m128i*)(d+k+8)); + a = _mm_min_epi16(a, v0); + b = _mm_max_epi16(b, v0); + v0 = _mm_loadu_si128((__m128i*)(d+k)); + q0 = _mm_max_epi16(q0, _mm_min_epi16(a, v0)); + q1 = _mm_min_epi16(q1, _mm_max_epi16(b, v0)); + v0 = _mm_loadu_si128((__m128i*)(d+k+9)); + q0 = _mm_max_epi16(q0, _mm_min_epi16(a, v0)); + q1 = _mm_min_epi16(q1, _mm_max_epi16(b, v0)); + } + q0 = _mm_max_epi16(q0, _mm_sub_epi16(_mm_setzero_si128(), q1)); + q0 = _mm_max_epi16(q0, _mm_unpackhi_epi64(q0, q0)); + q0 = _mm_max_epi16(q0, _mm_srli_si128(q0, 4)); + q0 = _mm_max_epi16(q0, _mm_srli_si128(q0, 2)); + threshold = (short)_mm_cvtsi128_si32(q0) - 1; + #else + int a0 = threshold; + for( k = 0; k < 16; k += 2 ) + { + int a = std::min((int)d[k+1], (int)d[k+2]); + a = std::min(a, (int)d[k+3]); + if( a <= a0 ) + continue; + a = std::min(a, (int)d[k+4]); + a = std::min(a, (int)d[k+5]); + a = std::min(a, (int)d[k+6]); + a = std::min(a, (int)d[k+7]); + a = std::min(a, (int)d[k+8]); + a0 = std::max(a0, std::min(a, (int)d[k])); + a0 = std::max(a0, std::min(a, (int)d[k+9])); + } + + int b0 = -a0; + for( k = 0; k < 16; k += 2 ) + { + int b = std::max((int)d[k+1], (int)d[k+2]); + b = std::max(b, (int)d[k+3]); + b = std::max(b, (int)d[k+4]); + b = std::max(b, (int)d[k+5]); + if( b >= b0 ) + continue; + b = std::max(b, (int)d[k+6]); + b = std::max(b, (int)d[k+7]); + b = std::max(b, (int)d[k+8]); + + b0 = std::min(b0, std::max(b, (int)d[k])); + b0 = std::min(b0, std::max(b, (int)d[k+9])); + } + + threshold = -b0-1; + #endif + + #if VERIFY_CORNERS + testCorner(ptr, pixel, K, N, threshold); + #endif + return threshold; + } + + template<> + int cornerScore<12>(const uchar* ptr, const int pixel[], int threshold) + { + const int K = 6, N = K*3 + 1; + int k, v = ptr[0]; + short d[N + 4]; + for( k = 0; k < N; k++ ) + d[k] = (short)(v - ptr[pixel[k]]); + #if CV_SSE2 + for( k = 0; k < 4; k++ ) + d[N+k] = d[k]; + #endif + + #if CV_SSE2 + __m128i q0 = _mm_set1_epi16(-1000), q1 = _mm_set1_epi16(1000); + for( k = 0; k < 16; k += 8 ) + { + __m128i v0 = _mm_loadu_si128((__m128i*)(d+k+1)); + __m128i v1 = _mm_loadu_si128((__m128i*)(d+k+2)); + __m128i a = _mm_min_epi16(v0, v1); + __m128i b = _mm_max_epi16(v0, v1); + v0 = _mm_loadu_si128((__m128i*)(d+k+3)); + a = _mm_min_epi16(a, v0); + b = _mm_max_epi16(b, v0); + v0 = _mm_loadu_si128((__m128i*)(d+k+4)); + a = _mm_min_epi16(a, v0); + b = _mm_max_epi16(b, v0); + v0 = _mm_loadu_si128((__m128i*)(d+k+5)); + a = _mm_min_epi16(a, v0); + b = _mm_max_epi16(b, v0); + v0 = _mm_loadu_si128((__m128i*)(d+k+6)); + a = _mm_min_epi16(a, v0); + b = _mm_max_epi16(b, v0); + v0 = _mm_loadu_si128((__m128i*)(d+k)); + q0 = _mm_max_epi16(q0, _mm_min_epi16(a, v0)); + q1 = _mm_min_epi16(q1, _mm_max_epi16(b, v0)); + v0 = _mm_loadu_si128((__m128i*)(d+k+7)); + q0 = _mm_max_epi16(q0, _mm_min_epi16(a, v0)); + q1 = _mm_min_epi16(q1, _mm_max_epi16(b, v0)); + } + q0 = _mm_max_epi16(q0, _mm_sub_epi16(_mm_setzero_si128(), q1)); + q0 = _mm_max_epi16(q0, _mm_unpackhi_epi64(q0, q0)); + q0 = _mm_max_epi16(q0, _mm_srli_si128(q0, 4)); + q0 = _mm_max_epi16(q0, _mm_srli_si128(q0, 2)); + threshold = (short)_mm_cvtsi128_si32(q0) - 1; + #else + int a0 = threshold; + for( k = 0; k < 12; k += 2 ) + { + int a = std::min((int)d[k+1], (int)d[k+2]); + if( a <= a0 ) + continue; + a = std::min(a, (int)d[k+3]); + a = std::min(a, (int)d[k+4]); + a = std::min(a, (int)d[k+5]); + a = std::min(a, (int)d[k+6]); + a0 = std::max(a0, std::min(a, (int)d[k])); + a0 = std::max(a0, std::min(a, (int)d[k+7])); + } + + int b0 = -a0; + for( k = 0; k < 12; k += 2 ) + { + int b = std::max((int)d[k+1], (int)d[k+2]); + b = std::max(b, (int)d[k+3]); + b = std::max(b, (int)d[k+4]); + if( b >= b0 ) + continue; + b = std::max(b, (int)d[k+5]); + b = std::max(b, (int)d[k+6]); + + b0 = std::min(b0, std::max(b, (int)d[k])); + b0 = std::min(b0, std::max(b, (int)d[k+7])); + } + + threshold = -b0-1; + #endif + + #if VERIFY_CORNERS + testCorner(ptr, pixel, K, N, threshold); + #endif + return threshold; + } + + template<> + int cornerScore<8>(const uchar* ptr, const int pixel[], int threshold) + { + const int K = 4, N = K*3 + 1; + int k, v = ptr[0]; + short d[N]; + for( k = 0; k < N; k++ ) + d[k] = (short)(v - ptr[pixel[k]]); + + #if CV_SSE2 + __m128i v0 = _mm_loadu_si128((__m128i*)(d+1)); + __m128i v1 = _mm_loadu_si128((__m128i*)(d+2)); + __m128i a = _mm_min_epi16(v0, v1); + __m128i b = _mm_max_epi16(v0, v1); + v0 = _mm_loadu_si128((__m128i*)(d+3)); + a = _mm_min_epi16(a, v0); + b = _mm_max_epi16(b, v0); + v0 = _mm_loadu_si128((__m128i*)(d+4)); + a = _mm_min_epi16(a, v0); + b = _mm_max_epi16(b, v0); + v0 = _mm_loadu_si128((__m128i*)(d)); + __m128i q0 = _mm_min_epi16(a, v0); + __m128i q1 = _mm_max_epi16(b, v0); + v0 = _mm_loadu_si128((__m128i*)(d+5)); + q0 = _mm_max_epi16(q0, _mm_min_epi16(a, v0)); + q1 = _mm_min_epi16(q1, _mm_max_epi16(b, v0)); + q0 = _mm_max_epi16(q0, _mm_sub_epi16(_mm_setzero_si128(), q1)); + q0 = _mm_max_epi16(q0, _mm_unpackhi_epi64(q0, q0)); + q0 = _mm_max_epi16(q0, _mm_srli_si128(q0, 4)); + q0 = _mm_max_epi16(q0, _mm_srli_si128(q0, 2)); + threshold = (short)_mm_cvtsi128_si32(q0) - 1; + #else + int a0 = threshold; + for( k = 0; k < 8; k += 2 ) + { + int a = std::min((int)d[k+1], (int)d[k+2]); + if( a <= a0 ) + continue; + a = std::min(a, (int)d[k+3]); + a = std::min(a, (int)d[k+4]); + a0 = std::max(a0, std::min(a, (int)d[k])); + a0 = std::max(a0, std::min(a, (int)d[k+5])); + } + + int b0 = -a0; + for( k = 0; k < 8; k += 2 ) + { + int b = std::max((int)d[k+1], (int)d[k+2]); + b = std::max(b, (int)d[k+3]); + if( b >= b0 ) + continue; + b = std::max(b, (int)d[k+4]); + + b0 = std::min(b0, std::max(b, (int)d[k])); + b0 = std::min(b0, std::max(b, (int)d[k+5])); + } + + threshold = -b0-1; + #endif + + #if VERIFY_CORNERS + testCorner(ptr, pixel, K, N, threshold); + #endif + return threshold; + } + + void makeOffsets(int pixel[25], int rowStride, int patternSize) + { + static const int offsets16[][2] = + { + {0, 3}, { 1, 3}, { 2, 2}, { 3, 1}, { 3, 0}, { 3, -1}, { 2, -2}, { 1, -3}, + {0, -3}, {-1, -3}, {-2, -2}, {-3, -1}, {-3, 0}, {-3, 1}, {-2, 2}, {-1, 3} + }; + + static const int offsets12[][2] = + { + {0, 2}, { 1, 2}, { 2, 1}, { 2, 0}, { 2, -1}, { 1, -2}, + {0, -2}, {-1, -2}, {-2, -1}, {-2, 0}, {-2, 1}, {-1, 2} + }; + + static const int offsets8[][2] = + { + {0, 1}, { 1, 1}, { 1, 0}, { 1, -1}, + {0, -1}, {-1, -1}, {-1, 0}, {-1, 1} + }; + + const int (*offsets)[2] = patternSize == 16 ? offsets16 : + patternSize == 12 ? offsets12 : + patternSize == 8 ? offsets8 : 0; + + CV_Assert(pixel && offsets); + + int k = 0; + for( ; k < patternSize; k++ ) + pixel[k] = offsets[k][0] + offsets[k][1] * rowStride; + for( ; k < 25; k++ ) + pixel[k] = pixel[k - patternSize]; + } + + template + void FASTForPointSet_t( InputArray image, std::vector& keypoints, int threshold, bool nonmaxSuppression ) { + + Mat img = image.getMat(); + const int K = patternSize/2, N = patternSize + K + 1; + + int i, k, pixel[25]; + makeOffsets(pixel, (int)img.step, patternSize); + + keypoints.clear(); + + threshold = std::min(std::max(threshold, 0), 255); + + uchar threshold_tab[512]; + for( i = -255; i <= 255; i++ ) + threshold_tab[i+255] = (uchar)(i < -threshold ? 1 : i > threshold ? 2 : 0); + + AutoBuffer _buf((img.cols+16)*3*(sizeof(int) + sizeof(uchar)) + 128); + uchar* buf[3]; + buf[0] = _buf; buf[1] = buf[0] + img.cols; buf[2] = buf[1] + img.cols; + int* cpbuf[3]; + cpbuf[0] = (int*)alignPtr(buf[2] + img.cols, sizeof(int)) + 1; + cpbuf[1] = cpbuf[0] + img.cols + 1; + cpbuf[2] = cpbuf[1] + img.cols + 1; + memset(buf[0], 0, img.cols*3); + + // Calculate threshold for the keypoints + for (size_t keyPointIdx=0; keyPointIdx < keypoints.size(); keyPointIdx++) { + // Set response to -1: + // All keypoints with response <= 0 will be removed afterwards + keypoints[keyPointIdx].response = -1; + + // Poiter to keyPoint in image + Point keyPoint = keypoints[keyPointIdx].pt; + const uchar* ptr = img.ptr(keyPoint.y, keyPoint.x); + + // value of the pixel at certain position + int v = ptr[0]; + + // Initialize Lookup table + // If k=v --> tab[k] is at the center of the thrshold table + // The threshold table is made as follows: + // -255 -threshold 0 +threshold 255 + // 111111111111111111|0000000000000|0000000000000|222222222222222 + const uchar* tab = &threshold_tab[0] - v + 255; + + // Calculate the fast value + int d = tab[ptr[pixel[0]]] | tab[ptr[pixel[8]]]; + + if( d == 0 ) + continue; + + d &= tab[ptr[pixel[2]]] | tab[ptr[pixel[10]]]; + d &= tab[ptr[pixel[4]]] | tab[ptr[pixel[12]]]; + d &= tab[ptr[pixel[6]]] | tab[ptr[pixel[14]]]; + + if( d == 0 ) + continue; + + d &= tab[ptr[pixel[1]]] | tab[ptr[pixel[9]]]; + d &= tab[ptr[pixel[3]]] | tab[ptr[pixel[11]]]; + d &= tab[ptr[pixel[5]]] | tab[ptr[pixel[13]]]; + d &= tab[ptr[pixel[7]]] | tab[ptr[pixel[15]]]; + + // For at least half pixels darker than v count the number + if( d & 1 ) + { + int vt = v - threshold, count = 0; + + for(k = 0; k < N; k++ ) + { + int x = ptr[pixel[k]]; + if(x < vt) + { + if( ++count > K ) + { + // Calculate score + keypoints[keyPointIdx].response = (uchar)cornerScore(ptr, pixel, threshold); + // Non Maxima Supression I + if (nonmaxSuppression && keyPointIdx>0 && keypoints[keyPointIdx-1].response < keypoints[keyPointIdx].response) { + keypoints[keyPointIdx-1].response = -1; + } + break; + } + } + else + count = 0; + } + } + + // For at least half pixels brighter than v count the number + if(d & 2 ) + { + int vt = v + threshold, count = 0; + + for(k = 0; k < N; k++ ) + { + int x = ptr[pixel[k]]; + if(x > vt) + { + if( ++count > K ) + { + // Calculate score + keypoints[keyPointIdx].response = (uchar)cornerScore(ptr, pixel, threshold); + // Non Maxima Suppression I + if (nonmaxSuppression && keyPointIdx>0 &&keypoints[keyPointIdx-1].response < keypoints[keyPointIdx].response) { + keypoints[keyPointIdx-1].response = -1; + } + break; + } + } + else + count = 0; + } + } + + } + + // Remove unused Keypoints + size_t maxKeypointSize = keypoints.size(); + for (size_t keyPointIdx=maxKeypointSize; keyPointIdx > 0;) { + keyPointIdx--; + if (keypoints[keyPointIdx].response <= 0) { + keypoints.erase(keypoints.begin() + keyPointIdx); + } else if (nonmaxSuppression && keyPointIdx>0 && keypoints[keyPointIdx-1].response > keypoints[keyPointIdx].response) { + // Non Maxima Suppression II + keypoints.erase(keypoints.begin() + keyPointIdx); + } + } + } + + void FASTForPointSet(InputArray _img, std::vector& keypoints, int threshold, bool nonmax_suppression, int type) + { + if (keypoints.empty()) { + FAST(_img, keypoints, threshold, nonmax_suppression, type); + return; + } + + switch(type) { + case FastFeatureDetector::TYPE_5_8: + FASTForPointSet_t<8>(_img, keypoints, threshold, nonmax_suppression); + break; + case FastFeatureDetector::TYPE_7_12: + FASTForPointSet_t<12>(_img, keypoints, threshold, nonmax_suppression); + break; + case FastFeatureDetector::TYPE_9_16: + FASTForPointSet_t<16>(_img, keypoints, threshold, nonmax_suppression); + break; + } + } + } +}