double contrastThreshold = 0.04, double edgeThreshold = 10,
double sigma = 1.6);
+ /** @brief Create SIFT with specified descriptorType.
+ @param nfeatures The number of best features to retain. The features are ranked by their scores
+ (measured in SIFT algorithm as the local contrast)
+
+ @param nOctaveLayers The number of layers in each octave. 3 is the value used in D. Lowe paper. The
+ number of octaves is computed automatically from the image resolution.
+
+ @param contrastThreshold The contrast threshold used to filter out weak features in semi-uniform
+ (low-contrast) regions. The larger the threshold, the less features are produced by the detector.
+
+ @note The contrast threshold will be divided by nOctaveLayers when the filtering is applied. When
+ nOctaveLayers is set to default and if you want to use the value used in D. Lowe paper, 0.03, set
+ this argument to 0.09.
+
+ @param edgeThreshold The threshold used to filter out edge-like features. Note that the its meaning
+ is different from the contrastThreshold, i.e. the larger the edgeThreshold, the less features are
+ filtered out (more features are retained).
+
+ @param sigma The sigma of the Gaussian applied to the input image at the octave \#0. If your image
+ is captured with a weak camera with soft lenses, you might want to reduce the number.
+
+ @param descriptorType The type of descriptors. Only CV_32F and CV_8U are supported.
+ */
+ CV_WRAP static Ptr<SIFT> create(int nfeatures, int nOctaveLayers,
+ double contrastThreshold, double edgeThreshold,
+ double sigma, int descriptorType);
+
CV_WRAP virtual String getDefaultName() const CV_OVERRIDE;
};
public:
explicit SIFT_Impl( int nfeatures = 0, int nOctaveLayers = 3,
double contrastThreshold = 0.04, double edgeThreshold = 10,
- double sigma = 1.6);
+ double sigma = 1.6, int descriptorType = CV_32F );
//! returns the descriptor size in floats (128)
int descriptorSize() const CV_OVERRIDE;
CV_PROP_RW double contrastThreshold;
CV_PROP_RW double edgeThreshold;
CV_PROP_RW double sigma;
+ CV_PROP_RW int descriptor_type;
};
Ptr<SIFT> SIFT::create( int _nfeatures, int _nOctaveLayers,
double _contrastThreshold, double _edgeThreshold, double _sigma )
{
CV_TRACE_FUNCTION();
- return makePtr<SIFT_Impl>(_nfeatures, _nOctaveLayers, _contrastThreshold, _edgeThreshold, _sigma);
+
+ return makePtr<SIFT_Impl>(_nfeatures, _nOctaveLayers, _contrastThreshold, _edgeThreshold, _sigma, CV_32F);
+}
+
+Ptr<SIFT> SIFT::create( int _nfeatures, int _nOctaveLayers,
+ double _contrastThreshold, double _edgeThreshold, double _sigma, int _descriptorType )
+{
+ CV_TRACE_FUNCTION();
+
+ // SIFT descriptor supports 32bit floating point and 8bit unsigned int.
+ CV_Assert(_descriptorType == CV_32F || _descriptorType == CV_8U);
+ return makePtr<SIFT_Impl>(_nfeatures, _nOctaveLayers, _contrastThreshold, _edgeThreshold, _sigma, _descriptorType);
}
String SIFT::getDefaultName() const
static
void calcSIFTDescriptor(
const Mat& img, Point2f ptf, float ori, float scl,
- int d, int n, float* dst
+ int d, int n, Mat& dst, int row
)
{
CV_TRACE_FUNCTION();
- CV_CPU_DISPATCH(calcSIFTDescriptor, (img, ptf, ori, scl, d, n, dst),
+ CV_CPU_DISPATCH(calcSIFTDescriptor, (img, ptf, ori, scl, d, n, dst, row),
CV_CPU_DISPATCH_MODES_ALL);
}
float angle = 360.f - kpt.angle;
if(std::abs(angle - 360.f) < FLT_EPSILON)
angle = 0.f;
- calcSIFTDescriptor(img, ptf, angle, size*0.5f, d, n, descriptors.ptr<float>((int)i));
+ calcSIFTDescriptor(img, ptf, angle, size*0.5f, d, n, descriptors, i);
}
}
private:
//////////////////////////////////////////////////////////////////////////////////////////
SIFT_Impl::SIFT_Impl( int _nfeatures, int _nOctaveLayers,
- double _contrastThreshold, double _edgeThreshold, double _sigma )
+ double _contrastThreshold, double _edgeThreshold, double _sigma, int _descriptorType )
: nfeatures(_nfeatures), nOctaveLayers(_nOctaveLayers),
- contrastThreshold(_contrastThreshold), edgeThreshold(_edgeThreshold), sigma(_sigma)
+ contrastThreshold(_contrastThreshold), edgeThreshold(_edgeThreshold), sigma(_sigma), descriptor_type(_descriptorType)
{
}
int SIFT_Impl::descriptorType() const
{
- return CV_32F;
+ return descriptor_type;
}
int SIFT_Impl::defaultNorm() const
{
//t = (double)getTickCount();
int dsize = descriptorSize();
- _descriptors.create((int)keypoints.size(), dsize, CV_32F);
- Mat descriptors = _descriptors.getMat();
+ _descriptors.create((int)keypoints.size(), dsize, descriptor_type);
+ Mat descriptors = _descriptors.getMat();
calcDescriptors(gpyr, keypoints, descriptors, nOctaveLayers, firstOctave);
//t = (double)getTickCount() - t;
//printf("descriptor extraction time: %g\n", t*1000./tf);
void calcSIFTDescriptor(
const Mat& img, Point2f ptf, float ori, float scl,
- int d, int n, float* dst
+ int d, int n, Mat& dst, int row
);
void calcSIFTDescriptor(
const Mat& img, Point2f ptf, float ori, float scl,
- int d, int n, float* dst
+ int d, int n, Mat& dstMat, int row
)
{
CV_TRACE_FUNCTION();
int i, j, k, len = (radius*2+1)*(radius*2+1), histlen = (d+2)*(d+2)*(n+2);
int rows = img.rows, cols = img.cols;
- AutoBuffer<float> buf(len*6 + histlen);
- float *X = buf.data(), *Y = X + len, *Mag = Y, *Ori = Mag + len, *W = Ori + len;
- float *RBin = W + len, *CBin = RBin + len, *hist = CBin + len;
+ cv::utils::BufferArea area;
+ float *X = 0, *Y = 0, *Mag, *Ori = 0, *W = 0, *RBin = 0, *CBin = 0, *hist = 0, *rawDst = 0;
+ area.allocate(X, len, CV_SIMD_WIDTH);
+ area.allocate(Y, len, CV_SIMD_WIDTH);
+ area.allocate(Ori, len, CV_SIMD_WIDTH);
+ area.allocate(W, len, CV_SIMD_WIDTH);
+ area.allocate(RBin, len, CV_SIMD_WIDTH);
+ area.allocate(CBin, len, CV_SIMD_WIDTH);
+ area.allocate(hist, histlen, CV_SIMD_WIDTH);
+ area.allocate(rawDst, len, CV_SIMD_WIDTH);
+ area.commit();
+ Mag = Y;
for( i = 0; i < d+2; i++ )
{
const v_int32 __n_plus_2 = vx_setall_s32(n+2);
for( ; k <= len - vecsize; k += vecsize )
{
- v_float32 rbin = vx_load(RBin + k);
- v_float32 cbin = vx_load(CBin + k);
- v_float32 obin = (vx_load(Ori + k) - __ori) * __bins_per_rad;
- v_float32 mag = vx_load(Mag + k) * vx_load(W + k);
+ v_float32 rbin = vx_load_aligned(RBin + k);
+ v_float32 cbin = vx_load_aligned(CBin + k);
+ v_float32 obin = (vx_load_aligned(Ori + k) - __ori) * __bins_per_rad;
+ v_float32 mag = vx_load_aligned(Mag + k) * vx_load_aligned(W + k);
v_int32 r0 = v_floor(rbin);
v_int32 c0 = v_floor(cbin);
hist[idx] += hist[idx+n];
hist[idx+1] += hist[idx+n+1];
for( k = 0; k < n; k++ )
- dst[(i*d + j)*n + k] = hist[idx+k];
+ rawDst[(i*d + j)*n + k] = hist[idx+k];
}
// copy histogram to the descriptor,
// apply hysteresis thresholding
#if CV_SIMD
{
v_float32 __nrm2 = vx_setzero_f32();
- v_float32 __dst;
+ v_float32 __rawDst;
for( ; k <= len - v_float32::nlanes; k += v_float32::nlanes )
{
- __dst = vx_load(dst + k);
- __nrm2 = v_fma(__dst, __dst, __nrm2);
+ __rawDst = vx_load_aligned(rawDst + k);
+ __nrm2 = v_fma(__rawDst, __rawDst, __nrm2);
}
nrm2 = (float)v_reduce_sum(__nrm2);
}
#endif
for( ; k < len; k++ )
- nrm2 += dst[k]*dst[k];
+ nrm2 += rawDst[k]*rawDst[k];
float thr = std::sqrt(nrm2)*SIFT_DESCR_MAG_THR;
__m256 __thr = _mm256_set1_ps(thr);
for( ; i <= len - 8; i += 8 )
{
- __dst = _mm256_loadu_ps(&dst[i]);
+ __dst = _mm256_loadu_ps(&rawDst[i]);
__dst = _mm256_min_ps(__dst, __thr);
- _mm256_storeu_ps(&dst[i], __dst);
+ _mm256_storeu_ps(&rawDst[i], __dst);
#if CV_FMA3
__nrm2 = _mm256_fmadd_ps(__dst, __dst, __nrm2);
#else
#endif
for( ; i < len; i++ )
{
- float val = std::min(dst[i], thr);
- dst[i] = val;
+ float val = std::min(rawDst[i], thr);
+ rawDst[i] = val;
nrm2 += val*val;
}
nrm2 = SIFT_INT_DESCR_FCTR/std::max(std::sqrt(nrm2), FLT_EPSILON);
#if 1
k = 0;
+if( dstMat.type() == CV_32F )
+{
+ float* dst = dstMat.ptr<float>(row);
#if CV_SIMD
+ v_float32 __dst;
+ v_float32 __min = vx_setzero_f32();
+ v_float32 __max = vx_setall_f32(255.0f); // max of uchar
+ v_float32 __nrm2 = vx_setall_f32(nrm2);
+ for( k = 0; k <= len - v_float32::nlanes; k += v_float32::nlanes )
{
- v_float32 __dst;
- v_float32 __min = vx_setzero_f32();
- v_float32 __max = vx_setall_f32(255.0f); // max of uchar
- v_float32 __nrm2 = vx_setall_f32(nrm2);
- for( k = 0; k <= len - v_float32::nlanes; k += v_float32::nlanes )
- {
- __dst = vx_load(dst + k);
- __dst = v_min(v_max(v_cvt_f32(v_round(__dst * __nrm2)), __min), __max);
- v_store(dst + k, __dst);
- }
+ __dst = vx_load_aligned(rawDst + k);
+ __dst = v_min(v_max(v_cvt_f32(v_round(__dst * __nrm2)), __min), __max);
+ v_store(dst + k, __dst);
}
#endif
for( ; k < len; k++ )
{
- dst[k] = saturate_cast<uchar>(dst[k]*nrm2);
+ dst[k] = saturate_cast<uchar>(rawDst[k]*nrm2);
}
+}
+else // CV_8U
+{
+ uint8_t* dst = dstMat.ptr<uint8_t>(row);
+#if CV_SIMD
+ v_float32 __dst0, __dst1;
+ v_uint16 __pack01;
+ v_float32 __nrm2 = vx_setall_f32(nrm2);
+ for( k = 0; k <= len - v_float32::nlanes * 2; k += v_float32::nlanes * 2 )
+ {
+ __dst0 = vx_load_aligned(rawDst + k);
+ __dst1 = vx_load_aligned(rawDst + k + v_float32::nlanes);
+
+ __pack01 = v_pack_u(v_round(__dst0 * __nrm2), v_round(__dst1 * __nrm2));
+ v_pack_store(dst + k, __pack01);
+ }
+#endif
+ for( ; k < len; k++ )
+ {
+ dst[k] = saturate_cast<uchar>(rawDst[k]*nrm2);
+ }
+}
#else
+ float* dst = dstMat.ptr<float>(row);
float nrm1 = 0;
for( k = 0; k < len; k++ )
{
- dst[k] *= nrm2;
- nrm1 += dst[k];
+ rawDst[k] *= nrm2;
+ nrm1 += rawDst[k];
}
nrm1 = 1.f/std::max(nrm1, FLT_EPSILON);
+if( dstMat.type() == CV_32F )
+{
for( k = 0; k < len; k++ )
{
- dst[k] = std::sqrt(dst[k] * nrm1);//saturate_cast<uchar>(std::sqrt(dst[k] * nrm1)*SIFT_INT_DESCR_FCTR);
+ dst[k] = std::sqrt(rawDst[k] * nrm1);
}
+}
+else // CV_8U
+{
+ for( k = 0; k < len; k++ )
+ {
+ dst[k] = saturate_cast<uchar>(std::sqrt(rawDst[k] * nrm1)*SIFT_INT_DESCR_FCTR);
+ }
+}
#endif
}
--- /dev/null
+// This file is part of OpenCV project.
+// It is subject to the license terms in the LICENSE file found in the top-level directory
+// of this distribution and at http://opencv.org/license.html
+
+#include "test_precomp.hpp"
+
+namespace opencv_test { namespace {
+
+TEST(Features2d_SIFT, descriptor_type)
+{
+ Mat image = imread(cvtest::findDataFile("features2d/tsukuba.png"));
+ ASSERT_FALSE(image.empty());
+
+ Mat gray;
+ cvtColor(image, gray, COLOR_BGR2GRAY);
+
+ vector<KeyPoint> keypoints;
+ Mat descriptorsFloat, descriptorsUchar;
+ Ptr<SIFT> siftFloat = cv::SIFT::create(0, 3, 0.04, 10, 1.6, CV_32F);
+ siftFloat->detectAndCompute(gray, Mat(), keypoints, descriptorsFloat, false);
+ ASSERT_EQ(descriptorsFloat.type(), CV_32F) << "type mismatch";
+
+ Ptr<SIFT> siftUchar = cv::SIFT::create(0, 3, 0.04, 10, 1.6, CV_8U);
+ siftUchar->detectAndCompute(gray, Mat(), keypoints, descriptorsUchar, false);
+ ASSERT_EQ(descriptorsUchar.type(), CV_8U) << "type mismatch";
+
+ Mat descriptorsFloat2;
+ descriptorsUchar.assignTo(descriptorsFloat2, CV_32F);
+ Mat diff = descriptorsFloat != descriptorsFloat2;
+ ASSERT_EQ(countNonZero(diff), 0) << "descriptors are not identical";
+}
+
+
+}} // namespace