Program Listing for File xf_hog_descriptor_pm.hpp
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/*
* Copyright 2019 Xilinx, Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#ifndef _XF_HOG_DESCRIPTOR_PM_HPP_
#define _XF_HOG_DESCRIPTOR_PM_HPP_
#ifndef __cplusplus
#error C++ is needed to include this header
#endif
#include "../core/xf_math.h"
// to convert the radians value to degrees
#define XF_NORM_FACTOR 58671 // (180/PI) in Q6.10
/***********************************************************************************************
* xFHOGPhaseMagnitudeKernel : The Gradient Phase and Gradient magnitude Computation Kernel.
* This kernel takes two gradients in XF_9SP depth and computes the angles and magnitude
* for each pixel and store this in a XF_9UP images.
*
* The Input arguments are _gradx_stream, _grady_stream
* _gradx_stream --> Gradient X data from the gradient computation function of
* depth XF_9SP.
* _grady_stream --> Gradient Y data from the gradient computation function of
* depth XF_9SP.
* _phase_stream --> phase computed image of depth XF_16UP.
* _mag_stream --> magnitude computed image of depth XF_16UP.
*
* Depending on NPC, 1 or 8 pixels are read and gradient values are calculated.
**********************************************************************************************/
template <int ROWS,
int COLS,
int DEPTH_SRC,
int DEPTH_DST,
int NPC,
int WORDWIDTH_SRC,
int WORDWIDTH_DST,
int COLS_TRIP>
void xFHOGPhaseMagnitudeKernel(hls::stream<XF_SNAME(WORDWIDTH_SRC)>& _gradx_stream,
hls::stream<XF_SNAME(WORDWIDTH_SRC)>& _grady_stream,
hls::stream<XF_SNAME(WORDWIDTH_DST)>& _phase_stream,
hls::stream<XF_SNAME(WORDWIDTH_DST)>& _mag_stream,
uint16_t height,
uint16_t width) {
// Data in the packed format
XF_SNAME(WORDWIDTH_SRC) grad_x_packed_val, grad_y_packed_val;
XF_SNAME(WORDWIDTH_DST) phase_packed_val, mag_packed_val;
// declaring the loop variables
uint16_t i, j;
uint16_t k, l;
// VARIABLES FOR PHASE KERNEL
// Fixed point format of x and y, x = QM1.N1, y = QM2.N2 // Q9.0 format input
int M1, N1, M2, N2;
M1 = XF_PIXELDEPTH(DEPTH_SRC);
N1 = 0;
M2 = M1;
N2 = N1;
rowLoop:
for (i = 0; i < height; i++) {
// clang-format off
#pragma HLS LOOP_TRIPCOUNT min=ROWS max=ROWS
#pragma HLS LOOP_FLATTEN OFF
// clang-format on
colLoop:
for (j = 0; j < width; j++) {
// clang-format off
#pragma HLS LOOP_TRIPCOUNT min=COLS_TRIP max=COLS_TRIP
#pragma HLS PIPELINE
// clang-format on
grad_x_packed_val = (XF_SNAME(WORDWIDTH_SRC))(_gradx_stream.read());
grad_y_packed_val = (XF_SNAME(WORDWIDTH_SRC))(_grady_stream.read());
uchar_t step_src = XF_PIXELDEPTH(DEPTH_SRC);
uchar_t step_dst = XF_PIXELDEPTH(DEPTH_DST);
uint16_t proc_loop_src = XF_PIXELDEPTH(DEPTH_SRC) << XF_BITSHIFT(NPC);
uint16_t proc_loop_dst = XF_PIXELDEPTH(DEPTH_DST) << XF_BITSHIFT(NPC);
procLoop:
for (k = 0, l = 0; k < proc_loop_src, l < proc_loop_dst; k += step_src, l += step_dst) {
// clang-format off
#pragma HLS UNROLL
// clang-format on
XF_PTNAME(DEPTH_SRC)
g_x = grad_x_packed_val.range(k + (step_src - 1), k); // Get bits from certain range of positions.
XF_PTNAME(DEPTH_SRC)
g_y = grad_y_packed_val.range(k + (step_src - 1), k); // Get bits from certain range of positions.
int16_t g_x_16_p, g_x_16_m, g_y_16_p, g_y_16_m;
g_x_16_p = g_x_16_m = g_x;
g_y_16_p = g_y_16_m = g_y;
// output will be in the radians
int16_t ret = 0;
int result_temp = 0;
ret = xf::cv::Atan2LUT8(g_x_16_p, g_y_16_p, M1, N1, M2, N2);
if ((ret < 0) || ((ret == 0) && (g_y_16_p < 0)))
result_temp = ret + XF_PI_FIXED + XF_PI_FIXED;
else
result_temp = ret;
// converting the radians value to degree
// instead of removing complete 22 fractional bits, we shift only 15 times, for we have some precision
// for HoG gradient computation
XF_PTNAME(DEPTH_DST) result_phase = ((XF_NORM_FACTOR * result_temp) >> 15); // Q9.7 format
// absolute difference of the input data
__HOG_ABS(g_x_16_m);
__HOG_ABS(g_y_16_m);
ap_uint17_t gx_sq = (uchar_t)g_x_16_m * (uchar_t)g_x_16_m;
ap_uint17_t gy_sq = (uchar_t)g_y_16_m * (uchar_t)g_y_16_m;
// perform square root for the result_tmp
ap_uint<17> sum_sq_grad = gx_sq + gy_sq;
ap_ufixed<31, 31, AP_TRN, AP_SAT> tmp_mag = ((ap_uint<31>)sum_sq_grad) << 14;
XF_PTNAME(DEPTH_DST) result_mag = xFSqrtHOG<16>(tmp_mag); // Q9.7 format
// packing the output pixel data
phase_packed_val.range(l + (step_dst - 1), l) = result_phase;
mag_packed_val.range(l + (step_dst - 1), l) = result_mag;
} // end of proc loop
_phase_stream.write(phase_packed_val);
_mag_stream.write(mag_packed_val);
} // end of col loop
} // end of row loop
} // end of function
/*******************************************************************
* xFPhaseMagnitude: This function acts as a wrapper function and
* calls the phaseMagnitude Kernel function.
*******************************************************************/
template <int ROWS, int COLS, int DEPTH_SRC, int DEPTH_DST, int NPC, int WORDWIDTH_SRC, int WORDWIDTH_DST>
void xFHOGPhaseMagnitude(hls::stream<XF_SNAME(WORDWIDTH_SRC)>& _grad_x,
hls::stream<XF_SNAME(WORDWIDTH_SRC)>& _grad_y,
hls::stream<XF_SNAME(WORDWIDTH_DST)>& _phase_stream,
hls::stream<XF_SNAME(WORDWIDTH_DST)>& _mag_stream,
uint16_t height,
uint16_t width) {
#ifndef __SYNTHESIS__
assert((DEPTH_SRC == XF_9SP) && "DEPTH_SRC must be XF_9SP");
assert((DEPTH_DST == XF_16UP) && "DEPTH_DST must be of type XF_16UP");
assert(((NPC == XF_NPPC1) || (NPC == XF_NPPC8) || (NPC == XF_NPPC16)) &&
"NPC must be XF_NPPC1, XF_NPPC8 or XF_NPPC16");
assert(((WORDWIDTH_SRC == XF_9UW) || (WORDWIDTH_SRC == XF_72UW) || (WORDWIDTH_SRC == XF_144UW)) &&
"WORDWIDTH_SRC must be XF_9UW, XF_72UW or XF_144UW");
assert(((WORDWIDTH_DST == XF_16UW) || (WORDWIDTH_DST == XF_128UW) || (WORDWIDTH_DST == XF_256UW)) &&
"WORDWIDTH_DST must be XF_16UW, XF_128UW or XF_256UW");
#endif
xFHOGPhaseMagnitudeKernel<ROWS, COLS, DEPTH_SRC, DEPTH_DST, NPC, WORDWIDTH_SRC, WORDWIDTH_DST,
(COLS >> XF_BITSHIFT(NPC))>(_grad_x, _grad_y, _phase_stream, _mag_stream, height, width);
}
#endif // _XF_HOG_DESCRIPTOR_PM_HPP_