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/*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 "precomp.hpp"
#include "opencv2/core/hal/intrin.hpp"
#include <iostream>
namespace cv
{
/* NOTE:
*
* Sobel-x: -1 0 1
* -2 0 2
* -1 0 1
*
* Sobel-y: -1 -2 -1
* 0 0 0
* 1 2 1
*/
template <typename T>
static inline void spatialGradientKernel( T& vx, T& vy,
const T& v00, const T& v01, const T& v02,
const T& v10, const T& v12,
const T& v20, const T& v21, const T& v22 )
{
// vx = (v22 - v00) + (v02 - v20) + 2 * (v12 - v10)
// vy = (v22 - v00) + (v20 - v02) + 2 * (v21 - v01)
T tmp_add = v22 - v00,
tmp_sub = v02 - v20,
tmp_x = v12 - v10,
tmp_y = v21 - v01;
vx = tmp_add + tmp_sub + tmp_x + tmp_x;
vy = tmp_add - tmp_sub + tmp_y + tmp_y;
}
void spatialGradient( InputArray _src, OutputArray _dx, OutputArray _dy,
int ksize, int borderType )
{
// Prepare InputArray src
Mat src = _src.getMat();
CV_Assert( !src.empty() );
CV_Assert( src.type() == CV_8UC1 );
CV_Assert( borderType == BORDER_DEFAULT || borderType == BORDER_REPLICATE );
// Prepare OutputArrays dx, dy
_dx.create( src.size(), CV_16SC1 );
_dy.create( src.size(), CV_16SC1 );
Mat dx = _dx.getMat(),
dy = _dy.getMat();
// TODO: Allow for other kernel sizes
CV_Assert(ksize == 3);
// Get dimensions
const int H = src.rows,
W = src.cols;
// Row, column indices
int i = 0,
j = 0;
// Handle border types
int i_top = 0, // Case for H == 1 && W == 1 && BORDER_REPLICATE
i_bottom = H - 1,
j_offl = 0, // j offset from 0th pixel to reach -1st pixel
j_offr = 0; // j offset from W-1th pixel to reach Wth pixel
if ( borderType == BORDER_DEFAULT ) // Equiv. to BORDER_REFLECT_101
{
if ( H > 1 )
{
i_top = 1;
i_bottom = H - 2;
}
if ( W > 1 )
{
j_offl = 1;
j_offr = -1;
}
}
// Pointer to row vectors
uchar *p_src, *c_src, *n_src; // previous, current, next row
short *c_dx, *c_dy;
int i_start = 0;
int j_start = 0;
#if CV_SIMD128 && CV_SSE2
uchar *m_src;
short *n_dx, *n_dy;
// Characters in variable names have the following meanings:
// u: unsigned char
// s: signed int
//
// [row][column]
// m: offset -1
// n: offset 0
// p: offset 1
// Example: umn is offset -1 in row and offset 0 in column
for ( i = 0; i < H - 1; i += 2 )
{
if ( i == 0 ) p_src = src.ptr<uchar>(i_top);
else p_src = src.ptr<uchar>(i-1);
c_src = src.ptr<uchar>(i);
n_src = src.ptr<uchar>(i+1);
if ( i == H - 2 ) m_src = src.ptr<uchar>(i_bottom);
else m_src = src.ptr<uchar>(i+2);
c_dx = dx.ptr<short>(i);
c_dy = dy.ptr<short>(i);
n_dx = dx.ptr<short>(i+1);
n_dy = dy.ptr<short>(i+1);
v_uint8x16 v_select_m = v_uint8x16(0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0xFF);
// Process rest of columns 16-column chunks at a time
for ( j = 1; j < W - 16; j += 16 )
{
// Load top row for 3x3 Sobel filter
v_uint8x16 v_um = v_load(&p_src[j-1]);
v_uint8x16 v_up = v_load(&p_src[j+1]);
// TODO: Replace _mm_slli_si128 with hal method
v_uint8x16 v_un = v_select(v_select_m, v_uint8x16(_mm_slli_si128(v_up.val, 1)),
v_uint8x16(_mm_srli_si128(v_um.val, 1)));
v_uint16x8 v_um1, v_um2, v_un1, v_un2, v_up1, v_up2;
v_expand(v_um, v_um1, v_um2);
v_expand(v_un, v_un1, v_un2);
v_expand(v_up, v_up1, v_up2);
v_int16x8 v_s1m1 = v_reinterpret_as_s16(v_um1);
v_int16x8 v_s1m2 = v_reinterpret_as_s16(v_um2);
v_int16x8 v_s1n1 = v_reinterpret_as_s16(v_un1);
v_int16x8 v_s1n2 = v_reinterpret_as_s16(v_un2);
v_int16x8 v_s1p1 = v_reinterpret_as_s16(v_up1);
v_int16x8 v_s1p2 = v_reinterpret_as_s16(v_up2);
// Load second row for 3x3 Sobel filter
v_um = v_load(&c_src[j-1]);
v_up = v_load(&c_src[j+1]);
// TODO: Replace _mm_slli_si128 with hal method
v_un = v_select(v_select_m, v_uint8x16(_mm_slli_si128(v_up.val, 1)),
v_uint8x16(_mm_srli_si128(v_um.val, 1)));
v_expand(v_um, v_um1, v_um2);
v_expand(v_un, v_un1, v_un2);
v_expand(v_up, v_up1, v_up2);
v_int16x8 v_s2m1 = v_reinterpret_as_s16(v_um1);
v_int16x8 v_s2m2 = v_reinterpret_as_s16(v_um2);
v_int16x8 v_s2n1 = v_reinterpret_as_s16(v_un1);
v_int16x8 v_s2n2 = v_reinterpret_as_s16(v_un2);
v_int16x8 v_s2p1 = v_reinterpret_as_s16(v_up1);
v_int16x8 v_s2p2 = v_reinterpret_as_s16(v_up2);
// Load third row for 3x3 Sobel filter
v_um = v_load(&n_src[j-1]);
v_up = v_load(&n_src[j+1]);
// TODO: Replace _mm_slli_si128 with hal method
v_un = v_select(v_select_m, v_uint8x16(_mm_slli_si128(v_up.val, 1)),
v_uint8x16(_mm_srli_si128(v_um.val, 1)));
v_expand(v_um, v_um1, v_um2);
v_expand(v_un, v_un1, v_un2);
v_expand(v_up, v_up1, v_up2);
v_int16x8 v_s3m1 = v_reinterpret_as_s16(v_um1);
v_int16x8 v_s3m2 = v_reinterpret_as_s16(v_um2);
v_int16x8 v_s3n1 = v_reinterpret_as_s16(v_un1);
v_int16x8 v_s3n2 = v_reinterpret_as_s16(v_un2);
v_int16x8 v_s3p1 = v_reinterpret_as_s16(v_up1);
v_int16x8 v_s3p2 = v_reinterpret_as_s16(v_up2);
// dx & dy for rows 1, 2, 3
v_int16x8 v_sdx1, v_sdy1;
spatialGradientKernel<v_int16x8>( v_sdx1, v_sdy1,
v_s1m1, v_s1n1, v_s1p1,
v_s2m1, v_s2p1,
v_s3m1, v_s3n1, v_s3p1 );
v_int16x8 v_sdx2, v_sdy2;
spatialGradientKernel<v_int16x8>( v_sdx2, v_sdy2,
v_s1m2, v_s1n2, v_s1p2,
v_s2m2, v_s2p2,
v_s3m2, v_s3n2, v_s3p2 );
// Store
v_store(&c_dx[j], v_sdx1);
v_store(&c_dx[j+8], v_sdx2);
v_store(&c_dy[j], v_sdy1);
v_store(&c_dy[j+8], v_sdy2);
// Load fourth row for 3x3 Sobel filter
v_um = v_load(&m_src[j-1]);
v_up = v_load(&m_src[j+1]);
// TODO: Replace _mm_slli_si128 with hal method
v_un = v_select(v_select_m, v_uint8x16(_mm_slli_si128(v_up.val, 1)),
v_uint8x16(_mm_srli_si128(v_um.val, 1)));
v_expand(v_um, v_um1, v_um2);
v_expand(v_un, v_un1, v_un2);
v_expand(v_up, v_up1, v_up2);
v_int16x8 v_s4m1 = v_reinterpret_as_s16(v_um1);
v_int16x8 v_s4m2 = v_reinterpret_as_s16(v_um2);
v_int16x8 v_s4n1 = v_reinterpret_as_s16(v_un1);
v_int16x8 v_s4n2 = v_reinterpret_as_s16(v_un2);
v_int16x8 v_s4p1 = v_reinterpret_as_s16(v_up1);
v_int16x8 v_s4p2 = v_reinterpret_as_s16(v_up2);
// dx & dy for rows 2, 3, 4
spatialGradientKernel<v_int16x8>( v_sdx1, v_sdy1,
v_s2m1, v_s2n1, v_s2p1,
v_s3m1, v_s3p1,
v_s4m1, v_s4n1, v_s4p1 );
spatialGradientKernel<v_int16x8>( v_sdx2, v_sdy2,
v_s2m2, v_s2n2, v_s2p2,
v_s3m2, v_s3p2,
v_s4m2, v_s4n2, v_s4p2 );
// Store
v_store(&n_dx[j], v_sdx1);
v_store(&n_dx[j+8], v_sdx2);
v_store(&n_dy[j], v_sdy1);
v_store(&n_dy[j+8], v_sdy2);
}
}
i_start = i;
j_start = j;
#endif
int j_p, j_n;
uchar v00, v01, v02, v10, v11, v12, v20, v21, v22;
for ( i = 0; i < H; i++ )
{
if ( i == 0 ) p_src = src.ptr<uchar>(i_top);
else p_src = src.ptr<uchar>(i-1);
c_src = src.ptr<uchar>(i);
if ( i == H - 1 ) n_src = src.ptr<uchar>(i_bottom);
else n_src = src.ptr<uchar>(i+1);
c_dx = dx.ptr<short>(i);
c_dy = dy.ptr<short>(i);
// Process left-most column
j = 0;
j_p = j + j_offl;
j_n = 1;
if ( j_n >= W ) j_n = j + j_offr;
v00 = p_src[j_p]; v01 = p_src[j]; v02 = p_src[j_n];
v10 = c_src[j_p]; v11 = c_src[j]; v12 = c_src[j_n];
v20 = n_src[j_p]; v21 = n_src[j]; v22 = n_src[j_n];
spatialGradientKernel<short>( c_dx[0], c_dy[0], v00, v01, v02, v10,
v12, v20, v21, v22 );
v00 = v01; v10 = v11; v20 = v21;
v01 = v02; v11 = v12; v21 = v22;
// Process middle columns
j = i >= i_start ? 1 : j_start;
j_p = j - 1;
v00 = p_src[j_p]; v01 = p_src[j];
v10 = c_src[j_p]; v11 = c_src[j];
v20 = n_src[j_p]; v21 = n_src[j];
for ( ; j < W - 1; j++ )
{
// Get values for next column
j_n = j + 1; v02 = p_src[j_n]; v12 = c_src[j_n]; v22 = n_src[j_n];
spatialGradientKernel<short>( c_dx[j], c_dy[j], v00, v01, v02, v10,
v12, v20, v21, v22 );
// Move values back one column for next iteration
v00 = v01; v10 = v11; v20 = v21;
v01 = v02; v11 = v12; v21 = v22;
}
// Process right-most column
if ( j < W )
{
j_n = j + j_offr; v02 = p_src[j_n]; v12 = c_src[j_n]; v22 = n_src[j_n];
spatialGradientKernel<short>( c_dx[j], c_dy[j], v00, v01, v02, v10,
v12, v20, v21, v22 );
}
}
}
}