openmv/lib/imlib/lbp.c
iabdalkader 4ded9fba91 common: Remove xalloc.
Originally meant to abstract gc_collect but we could just use
m_alloc and friends. Also was meant to provide functions like
alloc0, alloc_maybe etc.. which are all available in MP anyway.

Signed-off-by: iabdalkader <i.abdalkader@gmail.com>
2025-06-27 14:50:16 +02:00

132 lines
4.9 KiB
C

/*
* SPDX-License-Identifier: MIT
*
* Copyright (C) 2013-2024 OpenMV, LLC.
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*
* LBPu2 8,2 Operator.
* Note: The distance function uses weights optimized for face recognition.
* Note: See Timo Ahonen's "Face Recognition with Local Binary Patterns".
*/
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include "imlib.h"
#include "file_utils.h"
#ifdef IMLIB_ENABLE_FIND_LBP
#define LBP_HIST_SIZE (59) //58 uniform hist + 1
#define LBP_NUM_REGIONS (7) //7x7 regions
#define LBP_DESC_SIZE (LBP_NUM_REGIONS * LBP_NUM_REGIONS * LBP_HIST_SIZE)
const static int8_t lbp_weights[49] = {
2, 1, 1, 1, 1, 1, 2,
2, 4, 4, 1, 4, 4, 2,
1, 1, 1, 0, 1, 1, 1,
0, 1, 1, 0, 1, 1, 0,
0, 1, 1, 1, 1, 1, 0,
0, 1, 1, 2, 1, 1, 0,
0, 1, 1, 1, 1, 1, 0,
};
const static uint8_t uniform_tbl[256] = {
0, 1, 2, 3, 4, 58, 5, 6, 7, 58, 58, 58, 8, 58, 9, 10,
11, 58, 58, 58, 58, 58, 58, 58, 12, 58, 58, 58, 13, 58, 14, 15,
16, 58, 58, 58, 58, 58, 58, 58, 58, 58, 58, 58, 58, 58, 58, 58,
17, 58, 58, 58, 58, 58, 58, 58, 18, 58, 58, 58, 19, 58, 20, 21,
22, 58, 58, 58, 58, 58, 58, 58, 58, 58, 58, 58, 58, 58, 58, 58,
58, 58, 58, 58, 58, 58, 58, 58, 58, 58, 58, 58, 58, 58, 58, 58,
23, 58, 58, 58, 58, 58, 58, 58, 58, 58, 58, 58, 58, 58, 58, 58,
24, 58, 58, 58, 58, 58, 58, 58, 25, 58, 58, 58, 26, 58, 27, 28,
29, 30, 58, 31, 58, 58, 58, 32, 58, 58, 58, 58, 58, 58, 58, 33,
58, 58, 58, 58, 58, 58, 58, 58, 58, 58, 58, 58, 58, 58, 58, 34,
58, 58, 58, 58, 58, 58, 58, 58, 58, 58, 58, 58, 58, 58, 58, 58,
58, 58, 58, 58, 58, 58, 58, 58, 58, 58, 58, 58, 58, 58, 58, 35,
36, 37, 58, 38, 58, 58, 58, 39, 58, 58, 58, 58, 58, 58, 58, 40,
58, 58, 58, 58, 58, 58, 58, 58, 58, 58, 58, 58, 58, 58, 58, 41,
42, 43, 58, 44, 58, 58, 58, 45, 58, 58, 58, 58, 58, 58, 58, 46,
47, 48, 58, 49, 58, 58, 58, 50, 51, 52, 58, 53, 54, 55, 56, 57
};
uint8_t *imlib_lbp_desc(image_t *image, rectangle_t *roi) {
int s = image->w; //stride
int RX = roi->w / LBP_NUM_REGIONS;
int RY = roi->h / LBP_NUM_REGIONS;
uint8_t *data = image->data;
uint8_t *desc = m_malloc0(LBP_DESC_SIZE);
for (int y = roi->y; y < (roi->y + roi->h) - 3; y++) {
int y_idx = ((y - roi->y) / RY) * LBP_NUM_REGIONS;
for (int x = roi->x; x < (roi->x + roi->w) - 3; x++) {
uint8_t lbp = 0;
uint8_t p = data[(y + 1) * s + x + 1];
int hist_idx = y_idx + (x - roi->x) / RX;
lbp |= (data[(y + 0) * s + x + 0] >= p) << 0;
lbp |= (data[(y + 0) * s + x + 1] >= p) << 1;
lbp |= (data[(y + 0) * s + x + 2] >= p) << 2;
lbp |= (data[(y + 1) * s + x + 2] >= p) << 3;
lbp |= (data[(y + 2) * s + x + 2] >= p) << 4;
lbp |= (data[(y + 2) * s + x + 1] >= p) << 5;
lbp |= (data[(y + 2) * s + x + 0] >= p) << 6;
lbp |= (data[(y + 1) * s + x + 0] >= p) << 7;
desc[hist_idx * LBP_HIST_SIZE + uniform_tbl[lbp]]++;
}
}
return desc;
}
int imlib_lbp_desc_distance(uint8_t *d0, uint8_t *d1) {
uint32_t sum = 0;
for (int i = 0; i < LBP_DESC_SIZE; i++) {
int w = lbp_weights[i / LBP_HIST_SIZE];
sum += w * ((((d0[i] - d1[i]) * (d0[i] - d1[i])) / IM_MAX((d0[i] + d1[i]), 1)));
}
return sum;
}
int imlib_lbp_desc_save(FIL *fp, uint8_t *desc) {
UINT bytes;
// Write descriptor
return file_ll_write(fp, desc, LBP_DESC_SIZE, &bytes);
}
int imlib_lbp_desc_load(FIL *fp, uint8_t **desc) {
UINT bytes;
FRESULT res = FR_OK;
*desc = NULL;
uint8_t *hist = m_malloc(LBP_DESC_SIZE);
// Read descriptor
res = file_ll_read(fp, hist, LBP_DESC_SIZE, &bytes);
if (res != FR_OK || bytes != LBP_DESC_SIZE) {
*desc = NULL;
m_free(hist);
} else {
*desc = hist;
}
return res;
}
#endif //IMLIB_ENABLE_FIND_LBP