1/*M///////////////////////////////////////////////////////////////////////////////////////
2//
3//  IMPORTANT: READ BEFORE DOWNLOADING, COPYING, INSTALLING OR USING.
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6//  If you do not agree to this license, do not download, install,
7//  copy or use the software.
8//
9//
10//                           License Agreement
11//                For Open Source Computer Vision Library
12//
13// Copyright (C) 2010-2012, Institute Of Software Chinese Academy Of Science, all rights reserved.
14// Copyright (C) 2010-2012, Advanced Micro Devices, Inc., all rights reserved.
15// Third party copyrights are property of their respective owners.
16//
17// @Authors
18//    Shengen Yan,yanshengen@gmail.com
19//
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44//M*/
45
46///////////////////////////////////////////////////////////////////////////////////////////////////
47/////////////////////////////////Macro for border type////////////////////////////////////////////
48/////////////////////////////////////////////////////////////////////////////////////////////////
49
50#ifdef BORDER_CONSTANT
51#elif defined BORDER_REPLICATE
52#define EXTRAPOLATE(x, maxV) \
53    { \
54        x = max(min(x, maxV - 1), 0); \
55    }
56#elif defined BORDER_WRAP
57#define EXTRAPOLATE(x, maxV) \
58    { \
59        if (x < 0) \
60            x -= ((x - maxV + 1) / maxV) * maxV; \
61        if (x >= maxV) \
62            x %= maxV; \
63    }
64#elif defined(BORDER_REFLECT) || defined(BORDER_REFLECT101)
65#define EXTRAPOLATE_(x, maxV, delta) \
66    { \
67        if (maxV == 1) \
68            x = 0; \
69        else \
70            do \
71            { \
72                if ( x < 0 ) \
73                    x = -x - 1 + delta; \
74                else \
75                    x = maxV - 1 - (x - maxV) - delta; \
76            } \
77            while (x >= maxV || x < 0); \
78    }
79#ifdef BORDER_REFLECT
80#define EXTRAPOLATE(x, maxV) EXTRAPOLATE_(x, maxV, 0)
81#else
82#define EXTRAPOLATE(x, maxV) EXTRAPOLATE_(x, maxV, 1)
83#endif
84#else
85#error No extrapolation method
86#endif
87
88#define THREADS 256
89
90///////////////////////////////////////////////////////////////////////////////////////////////////
91/////////////////////////////////////calcHarris////////////////////////////////////////////////////
92///////////////////////////////////////////////////////////////////////////////////////////////////
93
94__kernel void corner(__global const float * Dx, int dx_step, int dx_offset, int dx_whole_rows, int dx_whole_cols,
95                     __global const float * Dy, int dy_step, int dy_offset, int dy_whole_rows, int dy_whole_cols,
96                     __global uchar * dst, int dst_step, int dst_offset, int dst_rows, int dst_cols, float k)
97{
98    int col = get_local_id(0);
99    int gX = get_group_id(0);
100    int gY = get_group_id(1);
101    int gly = get_global_id(1);
102
103    int dx_x_off = (dx_offset % dx_step) >> 2;
104    int dx_y_off = dx_offset / dx_step;
105    int dy_x_off = (dy_offset % dy_step) >> 2;
106    int dy_y_off = dy_offset / dy_step;
107    int dst_x_off = (dst_offset % dst_step) >> 2;
108    int dst_y_off = dst_offset / dst_step;
109
110    int dx_startX = gX * (THREADS-ksX+1) - anX + dx_x_off;
111    int dx_startY = (gY << 1) - anY + dx_y_off;
112    int dy_startX = gX * (THREADS-ksX+1) - anX + dy_x_off;
113    int dy_startY = (gY << 1) - anY + dy_y_off;
114    int dst_startX = gX * (THREADS-ksX+1) + dst_x_off;
115    int dst_startY = (gY << 1) + dst_y_off;
116
117    float data[3][ksY+1];
118    __local float temp[6][THREADS];
119
120#ifdef BORDER_CONSTANT
121    for (int i=0; i < ksY+1; i++)
122    {
123        bool dx_con = dx_startX+col >= 0 && dx_startX+col < dx_whole_cols && dx_startY+i >= 0 && dx_startY+i < dx_whole_rows;
124        int indexDx = mad24(dx_startY+i, dx_step>>2, dx_startX+col);
125        float dx_s = dx_con ? Dx[indexDx] : 0.0f;
126
127        bool dy_con = dy_startX+col >= 0 && dy_startX+col < dy_whole_cols && dy_startY+i >= 0 && dy_startY+i < dy_whole_rows;
128        int indexDy = mad24(dy_startY+i, dy_step>>2, dy_startX+col);
129        float dy_s = dy_con ? Dy[indexDy] : 0.0f;
130
131        data[0][i] = dx_s * dx_s;
132        data[1][i] = dx_s * dy_s;
133        data[2][i] = dy_s * dy_s;
134    }
135#else
136    int clamped_col = min(2*dst_cols, col);
137    for (int i=0; i < ksY+1; i++)
138    {
139        int dx_selected_row = dx_startY+i, dx_selected_col = dx_startX+clamped_col;
140        EXTRAPOLATE(dx_selected_row, dx_whole_rows)
141        EXTRAPOLATE(dx_selected_col, dx_whole_cols)
142        float dx_s = Dx[mad24(dx_selected_row, dx_step>>2, dx_selected_col)];
143
144        int dy_selected_row = dy_startY+i, dy_selected_col = dy_startX+clamped_col;
145        EXTRAPOLATE(dy_selected_row, dy_whole_rows)
146        EXTRAPOLATE(dy_selected_col, dy_whole_cols)
147        float dy_s = Dy[mad24(dy_selected_row, dy_step>>2, dy_selected_col)];
148
149        data[0][i] = dx_s * dx_s;
150        data[1][i] = dx_s * dy_s;
151        data[2][i] = dy_s * dy_s;
152    }
153#endif
154    float sum0 = 0.0f, sum1 = 0.0f, sum2 = 0.0f;
155    for (int i=1; i < ksY; i++)
156    {
157        sum0 += data[0][i];
158        sum1 += data[1][i];
159        sum2 += data[2][i];
160    }
161
162    float sum01 = sum0 + data[0][0];
163    float sum02 = sum0 + data[0][ksY];
164    temp[0][col] = sum01;
165    temp[1][col] = sum02;
166    float sum11 = sum1 + data[1][0];
167    float sum12 = sum1 + data[1][ksY];
168    temp[2][col] = sum11;
169    temp[3][col] = sum12;
170    float sum21 = sum2 + data[2][0];
171    float sum22 = sum2 + data[2][ksY];
172    temp[4][col] = sum21;
173    temp[5][col] = sum22;
174    barrier(CLK_LOCAL_MEM_FENCE);
175
176    if (col < (THREADS - (ksX - 1)))
177    {
178        col += anX;
179        int posX = dst_startX - dst_x_off + col - anX;
180        int posY = (gly << 1);
181        int till = (ksX + 1) & 1;
182        float tmp_sum[6] = { 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f };
183        for (int k=0; k<6; k++)
184        {
185            float temp_sum = 0;
186            for (int i=-anX; i<=anX - till; i++)
187                temp_sum += temp[k][col+i];
188            tmp_sum[k] = temp_sum;
189        }
190
191#ifdef CORNER_HARRIS
192        if (posX < dst_cols && (posY) < dst_rows)
193        {
194            int dst_index = mad24(dst_step, dst_startY, (int)sizeof(float) * (dst_startX + col - anX));
195            *(__global float *)(dst + dst_index) =
196                    tmp_sum[0] * tmp_sum[4] - tmp_sum[2] * tmp_sum[2] - k * (tmp_sum[0] + tmp_sum[4]) * (tmp_sum[0] + tmp_sum[4]);
197        }
198        if (posX < dst_cols && (posY + 1) < dst_rows)
199        {
200            int dst_index = mad24(dst_step, dst_startY + 1, (int)sizeof(float) * (dst_startX + col - anX));
201            *(__global float *)(dst + dst_index) =
202                    tmp_sum[1] * tmp_sum[5] - tmp_sum[3] * tmp_sum[3] - k * (tmp_sum[1] + tmp_sum[5]) * (tmp_sum[1] + tmp_sum[5]);
203        }
204#elif defined CORNER_MINEIGENVAL
205        if (posX < dst_cols && (posY) < dst_rows)
206        {
207            int dst_index = mad24(dst_step, dst_startY, (int)sizeof(float) * (dst_startX + col - anX));
208            float a = tmp_sum[0] * 0.5f;
209            float b = tmp_sum[2];
210            float c = tmp_sum[4] * 0.5f;
211            *(__global float *)(dst + dst_index) = (float)((a+c) - native_sqrt((a-c)*(a-c) + b*b));
212        }
213        if (posX < dst_cols && (posY + 1) < dst_rows)
214        {
215            int dst_index = mad24(dst_step, dst_startY + 1, (int)sizeof(float) * (dst_startX + col - anX));
216            float a = tmp_sum[1] * 0.5f;
217            float b = tmp_sum[3];
218            float c = tmp_sum[5] * 0.5f;
219            *(__global float *)(dst + dst_index) = (float)((a+c) - native_sqrt((a-c)*(a-c) + b*b));
220        }
221#else
222#error "No such corners type"
223#endif
224    }
225}
226