opencv/modules/ocl/src/opencl/imgproc_canny.cl
2013-10-31 23:48:02 +04:00

722 lines
22 KiB
Common Lisp

/*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) 2010-2012, Multicoreware, Inc., all rights reserved.
// Copyright (C) 2010-2012, Advanced Micro Devices, Inc., all rights reserved.
// Third party copyrights are property of their respective owners.
//
// @Authors
// Peng Xiao, pengxiao@multicorewareinc.com
//
// 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*/
#ifdef L2GRAD
inline float calc(int x, int y)
{
return sqrt((float)(x * x + y * y));
}
#else
inline float calc(int x, int y)
{
return (float)abs(x) + abs(y);
}
#endif //
// Smoothing perpendicular to the derivative direction with a triangle filter
// only support 3x3 Sobel kernel
// h (-1) = 1, h (0) = 2, h (1) = 1
// h'(-1) = -1, h'(0) = 0, h'(1) = 1
// thus sobel 2D operator can be calculated as:
// h'(x, y) = h'(x)h(y) for x direction
//
// src input 8bit single channel image data
// dx_buf output dx buffer
// dy_buf output dy buffer
__kernel
void
__attribute__((reqd_work_group_size(16,16,1)))
calcSobelRowPass
(
__global const uchar * src,
__global int * dx_buf,
__global int * dy_buf,
int rows,
int cols,
int src_step,
int src_offset,
int dx_buf_step,
int dx_buf_offset,
int dy_buf_step,
int dy_buf_offset
)
{
dx_buf_step /= sizeof(*dx_buf);
dx_buf_offset /= sizeof(*dx_buf);
dy_buf_step /= sizeof(*dy_buf);
dy_buf_offset /= sizeof(*dy_buf);
int gidx = get_global_id(0);
int gidy = get_global_id(1);
int lidx = get_local_id(0);
int lidy = get_local_id(1);
__local int smem[16][18];
smem[lidy][lidx + 1] =
src[gidx + min(gidy, rows - 1) * src_step + src_offset];
if(lidx == 0)
{
smem[lidy][0] =
src[max(gidx - 1, 0) + min(gidy, rows - 1) * src_step + src_offset];
smem[lidy][17] =
src[min(gidx + 16, cols - 1) + min(gidy, rows - 1) * src_step + src_offset];
}
barrier(CLK_LOCAL_MEM_FENCE);
if(gidy < rows && gidx < cols)
{
dx_buf[gidx + gidy * dx_buf_step + dx_buf_offset] =
-smem[lidy][lidx] + smem[lidy][lidx + 2];
dy_buf[gidx + gidy * dy_buf_step + dy_buf_offset] =
smem[lidy][lidx] + 2 * smem[lidy][lidx + 1] + smem[lidy][lidx + 2];
}
}
// calculate the magnitude of the filter pass combining both x and y directions
// This is the buffered version(3x3 sobel)
//
// dx_buf dx buffer, calculated from calcSobelRowPass
// dy_buf dy buffer, calculated from calcSobelRowPass
// dx direvitive in x direction output
// dy direvitive in y direction output
// mag magnitude direvitive of xy output
__kernel
void
__attribute__((reqd_work_group_size(16,16,1)))
calcMagnitude_buf
(
__global const int * dx_buf,
__global const int * dy_buf,
__global int * dx,
__global int * dy,
__global float * mag,
int rows,
int cols,
int dx_buf_step,
int dx_buf_offset,
int dy_buf_step,
int dy_buf_offset,
int dx_step,
int dx_offset,
int dy_step,
int dy_offset,
int mag_step,
int mag_offset
)
{
dx_buf_step /= sizeof(*dx_buf);
dx_buf_offset /= sizeof(*dx_buf);
dy_buf_step /= sizeof(*dy_buf);
dy_buf_offset /= sizeof(*dy_buf);
dx_step /= sizeof(*dx);
dx_offset /= sizeof(*dx);
dy_step /= sizeof(*dy);
dy_offset /= sizeof(*dy);
mag_step /= sizeof(*mag);
mag_offset /= sizeof(*mag);
int gidx = get_global_id(0);
int gidy = get_global_id(1);
int lidx = get_local_id(0);
int lidy = get_local_id(1);
__local int sdx[18][16];
__local int sdy[18][16];
sdx[lidy + 1][lidx] =
dx_buf[gidx + min(gidy, rows - 1) * dx_buf_step + dx_buf_offset];
sdy[lidy + 1][lidx] =
dy_buf[gidx + min(gidy, rows - 1) * dy_buf_step + dy_buf_offset];
if(lidy == 0)
{
sdx[0][lidx] =
dx_buf[gidx + min(max(gidy-1,0),rows-1) * dx_buf_step + dx_buf_offset];
sdx[17][lidx] =
dx_buf[gidx + min(gidy + 16, rows - 1) * dx_buf_step + dx_buf_offset];
sdy[0][lidx] =
dy_buf[gidx + min(max(gidy-1,0),rows-1) * dy_buf_step + dy_buf_offset];
sdy[17][lidx] =
dy_buf[gidx + min(gidy + 16, rows - 1) * dy_buf_step + dy_buf_offset];
}
barrier(CLK_LOCAL_MEM_FENCE);
if(gidx < cols && gidy < rows)
{
int x = sdx[lidy][lidx] + 2 * sdx[lidy + 1][lidx] + sdx[lidy + 2][lidx];
int y = -sdy[lidy][lidx] + sdy[lidy + 2][lidx];
dx[gidx + gidy * dx_step + dx_offset] = x;
dy[gidx + gidy * dy_step + dy_offset] = y;
mag[(gidx + 1) + (gidy + 1) * mag_step + mag_offset] = calc(x, y);
}
}
// calculate the magnitude of the filter pass combining both x and y directions
// This is the non-buffered version(non-3x3 sobel)
//
// dx_buf dx buffer, calculated from calcSobelRowPass
// dy_buf dy buffer, calculated from calcSobelRowPass
// dx direvitive in x direction output
// dy direvitive in y direction output
// mag magnitude direvitive of xy output
__kernel
void calcMagnitude
(
__global const int * dx,
__global const int * dy,
__global float * mag,
int rows,
int cols,
int dx_step,
int dx_offset,
int dy_step,
int dy_offset,
int mag_step,
int mag_offset
)
{
dx_step /= sizeof(*dx);
dx_offset /= sizeof(*dx);
dy_step /= sizeof(*dy);
dy_offset /= sizeof(*dy);
mag_step /= sizeof(*mag);
mag_offset /= sizeof(*mag);
int gidx = get_global_id(0);
int gidy = get_global_id(1);
if(gidy < rows && gidx < cols)
{
mag[(gidx + 1) + (gidy + 1) * mag_step + mag_offset] =
calc(
dx[gidx + gidy * dx_step + dx_offset],
dy[gidx + gidy * dy_step + dy_offset]
);
}
}
//////////////////////////////////////////////////////////////////////////////////////////
// 0.4142135623730950488016887242097 is tan(22.5)
#define CANNY_SHIFT 15
#ifdef DOUBLE_SUPPORT
#define TG22 (int)(0.4142135623730950488016887242097*(1<<CANNY_SHIFT) + 0.5)
#else
#define TG22 (int)(0.4142135623730950488016887242097f*(1<<CANNY_SHIFT) + 0.5f)
#endif
//First pass of edge detection and non-maximum suppression
// edgetype is set to for each pixel:
// 0 - below low thres, not an edge
// 1 - maybe an edge
// 2 - is an edge, either magnitude is greater than high thres, or
// Given estimates of the image gradients, a search is then carried out
// to determine if the gradient magnitude assumes a local maximum in the gradient direction.
// if the rounded gradient angle is zero degrees (i.e. the edge is in the north-south direction) the point will be considered to be on the edge if its gradient magnitude is greater than the magnitudes in the west and east directions,
// if the rounded gradient angle is 90 degrees (i.e. the edge is in the east-west direction) the point will be considered to be on the edge if its gradient magnitude is greater than the magnitudes in the north and south directions,
// if the rounded gradient angle is 135 degrees (i.e. the edge is in the north east-south west direction) the point will be considered to be on the edge if its gradient magnitude is greater than the magnitudes in the north west and south east directions,
// if the rounded gradient angle is 45 degrees (i.e. the edge is in the north west-south east direction)the point will be considered to be on the edge if its gradient magnitude is greater than the magnitudes in the north east and south west directions.
//
// dx, dy direvitives of x and y direction
// mag magnitudes calculated from calcMagnitude function
// map output containing raw edge types
__kernel
void
__attribute__((reqd_work_group_size(16,16,1)))
calcMap
(
__global const int * dx,
__global const int * dy,
__global const float * mag,
__global int * map,
int rows,
int cols,
float low_thresh,
float high_thresh,
int dx_step,
int dx_offset,
int dy_step,
int dy_offset,
int mag_step,
int mag_offset,
int map_step,
int map_offset
)
{
dx_step /= sizeof(*dx);
dx_offset /= sizeof(*dx);
dy_step /= sizeof(*dy);
dy_offset /= sizeof(*dy);
mag_step /= sizeof(*mag);
mag_offset /= sizeof(*mag);
map_step /= sizeof(*map);
map_offset /= sizeof(*map);
mag += mag_offset;
map += map_offset;
__local float smem[18][18];
int gidx = get_global_id(0);
int gidy = get_global_id(1);
int lidx = get_local_id(0);
int lidy = get_local_id(1);
int grp_idx = get_global_id(0) & 0xFFFFF0;
int grp_idy = get_global_id(1) & 0xFFFFF0;
int tid = lidx + lidy * 16;
int lx = tid % 18;
int ly = tid / 18;
if(ly < 14)
{
smem[ly][lx] =
mag[grp_idx + lx + min(grp_idy + ly, rows - 1) * mag_step];
}
if(ly < 4 && grp_idy + ly + 14 <= rows && grp_idx + lx <= cols)
{
smem[ly + 14][lx] =
mag[grp_idx + lx + min(grp_idy + ly + 14, rows -1) * mag_step];
}
barrier(CLK_LOCAL_MEM_FENCE);
if(gidy < rows && gidx < cols)
{
int x = dx[gidx + gidy * dx_step];
int y = dy[gidx + gidy * dy_step];
const int s = (x ^ y) < 0 ? -1 : 1;
const float m = smem[lidy + 1][lidx + 1];
x = abs(x);
y = abs(y);
// 0 - the pixel can not belong to an edge
// 1 - the pixel might belong to an edge
// 2 - the pixel does belong to an edge
int edge_type = 0;
if(m > low_thresh)
{
const int tg22x = x * TG22;
const int tg67x = tg22x + (x << (1 + CANNY_SHIFT));
y <<= CANNY_SHIFT;
if(y < tg22x)
{
if(m > smem[lidy + 1][lidx] && m >= smem[lidy + 1][lidx + 2])
{
edge_type = 1 + (int)(m > high_thresh);
}
}
else if (y > tg67x)
{
if(m > smem[lidy][lidx + 1]&& m >= smem[lidy + 2][lidx + 1])
{
edge_type = 1 + (int)(m > high_thresh);
}
}
else
{
if(m > smem[lidy][lidx + 1 - s]&& m > smem[lidy + 2][lidx + 1 + s])
{
edge_type = 1 + (int)(m > high_thresh);
}
}
}
map[gidx + 1 + (gidy + 1) * map_step] = edge_type;
}
}
#undef CANNY_SHIFT
#undef TG22
struct PtrStepSz {
__global int *ptr;
int step;
int rows, cols;
};
inline int get(struct PtrStepSz data, int y, int x) { return *((__global int *)((__global char*)data.ptr + data.step * y + sizeof(int) * x)); }
inline void set(struct PtrStepSz data, int y, int x, int value) { *((__global int *)((__global char*)data.ptr + data.step * y + sizeof(int) * x)) = value; }
//////////////////////////////////////////////////////////////////////////////////////////
// do Hysteresis for pixel whose edge type is 1
//
// If candidate pixel (edge type is 1) has a neighbour pixel (in 3x3 area) with type 2, it is believed to be part of an edge and
// marked as edge. Each thread will iterate for 16 times to connect local edges.
// Candidate pixel being identified as edge will then be tested if there is nearby potiential edge points. If there is, counter will
// be incremented by 1 and the point location is stored. These potiential candidates will be processed further in next kernel.
//
// map raw edge type results calculated from calcMap.
// st the potiential edge points found in this kernel call
// counter the number of potiential edge points
__kernel
void
__attribute__((reqd_work_group_size(16,16,1)))
edgesHysteresisLocal
(
__global int * map_ptr,
__global ushort2 * st,
__global unsigned int * counter,
int rows,
int cols,
int map_step,
int map_offset
)
{
#if 0
map_step /= sizeof(*map);
map_offset /= sizeof(*map);
const __global int* map = map_ptr + map_offset;
__local int smem[18][18];
int gidx = get_global_id(0);
int gidy = get_global_id(1);
int lidx = get_local_id(0);
int lidy = get_local_id(1);
int grp_idx = get_global_id(0) & 0xFFFFF0;
int grp_idy = get_global_id(1) & 0xFFFFF0;
int tid = lidx + lidy * 16;
int lx = tid % 18;
int ly = tid / 18;
if(ly < 14)
{
smem[ly][lx] =
map[grp_idx + lx + min(grp_idy + ly, rows - 1) * map_step];
}
if(ly < 4 && grp_idy + ly + 14 <= rows && grp_idx + lx <= cols)
{
smem[ly + 14][lx] =
map[grp_idx + lx + min(grp_idy + ly + 14, rows - 1) * map_step];
}
barrier(CLK_LOCAL_MEM_FENCE);
if(gidy < rows && gidx < cols)
{
int n;
#pragma unroll
for (int k = 0; k < 16; ++k)
{
n = 0;
if (smem[lidy + 1][lidx + 1] == 1)
{
n += smem[lidy ][lidx ] == 2;
n += smem[lidy ][lidx + 1] == 2;
n += smem[lidy ][lidx + 2] == 2;
n += smem[lidy + 1][lidx ] == 2;
n += smem[lidy + 1][lidx + 2] == 2;
n += smem[lidy + 2][lidx ] == 2;
n += smem[lidy + 2][lidx + 1] == 2;
n += smem[lidy + 2][lidx + 2] == 2;
}
if (n > 0)
smem[lidy + 1][lidx + 1] = 2;
}
const int e = smem[lidy + 1][lidx + 1];
map[gidx + 1 + (gidy + 1) * map_step] = e;
n = 0;
if(e == 2)
{
n += smem[lidy ][lidx ] == 1;
n += smem[lidy ][lidx + 1] == 1;
n += smem[lidy ][lidx + 2] == 1;
n += smem[lidy + 1][lidx ] == 1;
n += smem[lidy + 1][lidx + 2] == 1;
n += smem[lidy + 2][lidx ] == 1;
n += smem[lidy + 2][lidx + 1] == 1;
n += smem[lidy + 2][lidx + 2] == 1;
}
if(n > 0)
{
unsigned int ind = atomic_inc(counter);
st[ind] = (ushort2)(gidx + 1, gidy + 1);
}
}
#else
struct PtrStepSz map = {((__global int *)((__global char*)map_ptr + map_offset)), map_step, rows, cols};
__local int smem[18][18];
int2 blockIdx = (int2)(get_group_id(0), get_group_id(1));
int2 blockDim = (int2)(get_local_size(0), get_local_size(1));
int2 threadIdx = (int2)(get_local_id(0), get_local_id(1));
const int x = blockIdx.x * blockDim.x + threadIdx.x;
const int y = blockIdx.y * blockDim.y + threadIdx.y;
smem[threadIdx.y + 1][threadIdx.x + 1] = x < map.cols && y < map.rows ? get(map, y, x) : 0;
if (threadIdx.y == 0)
smem[0][threadIdx.x + 1] = y > 0 ? get(map, y - 1, x) : 0;
if (threadIdx.y == blockDim.y - 1)
smem[blockDim.y + 1][threadIdx.x + 1] = y + 1 < map.rows ? get(map, y + 1, x) : 0;
if (threadIdx.x == 0)
smem[threadIdx.y + 1][0] = x > 0 ? get(map, y, x - 1) : 0;
if (threadIdx.x == blockDim.x - 1)
smem[threadIdx.y + 1][blockDim.x + 1] = x + 1 < map.cols ? get(map, y, x + 1) : 0;
if (threadIdx.x == 0 && threadIdx.y == 0)
smem[0][0] = y > 0 && x > 0 ? get(map, y - 1, x - 1) : 0;
if (threadIdx.x == blockDim.x - 1 && threadIdx.y == 0)
smem[0][blockDim.x + 1] = y > 0 && x + 1 < map.cols ? get(map, y - 1, x + 1) : 0;
if (threadIdx.x == 0 && threadIdx.y == blockDim.y - 1)
smem[blockDim.y + 1][0] = y + 1 < map.rows && x > 0 ? get(map, y + 1, x - 1) : 0;
if (threadIdx.x == blockDim.x - 1 && threadIdx.y == blockDim.y - 1)
smem[blockDim.y + 1][blockDim.x + 1] = y + 1 < map.rows && x + 1 < map.cols ? get(map, y + 1, x + 1) : 0;
barrier(CLK_LOCAL_MEM_FENCE);
if (x >= map.cols || y >= map.rows)
return;
int n;
#pragma unroll
for (int k = 0; k < 16; ++k)
{
n = 0;
if (smem[threadIdx.y + 1][threadIdx.x + 1] == 1)
{
n += smem[threadIdx.y ][threadIdx.x ] == 2;
n += smem[threadIdx.y ][threadIdx.x + 1] == 2;
n += smem[threadIdx.y ][threadIdx.x + 2] == 2;
n += smem[threadIdx.y + 1][threadIdx.x ] == 2;
n += smem[threadIdx.y + 1][threadIdx.x + 2] == 2;
n += smem[threadIdx.y + 2][threadIdx.x ] == 2;
n += smem[threadIdx.y + 2][threadIdx.x + 1] == 2;
n += smem[threadIdx.y + 2][threadIdx.x + 2] == 2;
}
if (n > 0)
smem[threadIdx.y + 1][threadIdx.x + 1] = 2;
}
const int e = smem[threadIdx.y + 1][threadIdx.x + 1];
set(map, y, x, e);
n = 0;
if (e == 2)
{
n += smem[threadIdx.y ][threadIdx.x ] == 1;
n += smem[threadIdx.y ][threadIdx.x + 1] == 1;
n += smem[threadIdx.y ][threadIdx.x + 2] == 1;
n += smem[threadIdx.y + 1][threadIdx.x ] == 1;
n += smem[threadIdx.y + 1][threadIdx.x + 2] == 1;
n += smem[threadIdx.y + 2][threadIdx.x ] == 1;
n += smem[threadIdx.y + 2][threadIdx.x + 1] == 1;
n += smem[threadIdx.y + 2][threadIdx.x + 2] == 1;
}
if (n > 0)
{
const int ind = atomic_inc(counter);
st[ind] = (ushort2)(x, y);
}
#endif
}
__constant int c_dx[8] = {-1, 0, 1, -1, 1, -1, 0, 1};
__constant int c_dy[8] = {-1, -1, -1, 0, 0, 1, 1, 1};
#define stack_size 512
__kernel
void
__attribute__((reqd_work_group_size(128,1,1)))
edgesHysteresisGlobal
(
__global int * map,
__global ushort2 * st1,
__global ushort2 * st2,
__global int * counter,
int rows,
int cols,
int count,
int map_step,
int map_offset
)
{
map_step /= sizeof(*map);
map_offset /= sizeof(*map);
map += map_offset;
int lidx = get_local_id(0);
int grp_idx = get_group_id(0);
int grp_idy = get_group_id(1);
__local unsigned int s_counter;
__local unsigned int s_ind;
__local ushort2 s_st[stack_size];
if(lidx == 0)
{
s_counter = 0;
}
barrier(CLK_LOCAL_MEM_FENCE);
int ind = mad24(grp_idy, (int)get_local_size(0), grp_idx);
if(ind < count)
{
ushort2 pos = st1[ind];
if (lidx < 8)
{
pos.x += c_dx[lidx];
pos.y += c_dy[lidx];
if (pos.x > 0 && pos.x <= cols && pos.y > 0 && pos.y <= rows && map[pos.x + pos.y * map_step] == 1)
{
map[pos.x + pos.y * map_step] = 2;
ind = atomic_inc(&s_counter);
s_st[ind] = pos;
}
}
barrier(CLK_LOCAL_MEM_FENCE);
while (s_counter > 0 && s_counter <= stack_size - get_local_size(0))
{
const int subTaskIdx = lidx >> 3;
const int portion = min(s_counter, (uint)(get_local_size(0)>> 3));
if (subTaskIdx < portion)
pos = s_st[s_counter - 1 - subTaskIdx];
barrier(CLK_LOCAL_MEM_FENCE);
if (lidx == 0)
s_counter -= portion;
barrier(CLK_LOCAL_MEM_FENCE);
if (subTaskIdx < portion)
{
pos.x += c_dx[lidx & 7];
pos.y += c_dy[lidx & 7];
if (pos.x > 0 && pos.x <= cols && pos.y > 0 && pos.y <= rows && map[pos.x + pos.y * map_step] == 1)
{
map[pos.x + pos.y * map_step] = 2;
ind = atomic_inc(&s_counter);
s_st[ind] = pos;
}
}
barrier(CLK_LOCAL_MEM_FENCE);
}
if (s_counter > 0)
{
if (lidx == 0)
{
ind = atomic_add(counter, s_counter);
s_ind = ind - s_counter;
}
barrier(CLK_LOCAL_MEM_FENCE);
ind = s_ind;
for (int i = lidx; i < (int)s_counter; i += get_local_size(0))
{
st2[ind + i] = s_st[i];
}
}
}
}
#undef stack_size
//Get the edge result. egde type of value 2 will be marked as an edge point and set to 255. Otherwise 0.
// map edge type mappings
// dst edge output
__kernel
void getEdges
(
__global const int * map,
__global uchar * dst,
int rows,
int cols,
int map_step,
int map_offset,
int dst_step,
int dst_offset
)
{
map_step /= sizeof(*map);
map_offset /= sizeof(*map);
int gidx = get_global_id(0);
int gidy = get_global_id(1);
if(gidy < rows && gidx < cols)
{
dst[gidx + gidy * dst_step] = (uchar)(-(map[gidx + 1 + (gidy + 1) * map_step + map_offset] >> 1));
}
}