algorithms.cpp

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/*
MIT License
 
Copyright (c) 2021 Analog Devices, Inc.
 
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.
*/
#include "algorithms.h"
#include "opencv_undistort.h"
 
#include <cstring>
#include <math.h>
 
uint32_t Algorithms::GenerateXYZTables(
    const float **pp_x_table, const float **pp_y_table,
    const float **pp_z_table, CameraIntrinsics *p_intr_data,
    uint32_t n_sensor_rows, uint32_t n_sensor_cols, uint32_t n_out_rows,
    uint32_t n_out_cols, uint32_t n_offset_rows, uint32_t n_offset_cols,
    uint8_t row_bin_factor, uint8_t col_bin_factor, uint8_t iter) {
    uint32_t n_cols = n_sensor_cols / col_bin_factor;
    uint32_t n_rows = n_sensor_rows / row_bin_factor;
 
    float *p_xp = (float *)malloc(n_rows * n_cols * sizeof(float));
    float *p_yp = (float *)malloc(n_rows * n_cols * sizeof(float));
    float *p_z = (float *)malloc(n_rows * n_cols * sizeof(float));
 
    if ((p_xp == NULL) || (p_yp == NULL) || ((p_z == NULL))) {
        if (p_xp)
            free(p_xp);
        if (p_yp)
            free(p_yp);
        if (p_z)
            free(p_z);
        return -1;
    }
 
    // Adjust values based on optical center and focal length
    float cx = p_intr_data->cx / row_bin_factor;
    float cy = p_intr_data->cy / col_bin_factor;
    // float codx = p_intr_data->codx;
    //float cody = p_intr_data->cody;
 
    float r_min = sqrt((float)(n_rows * n_rows + n_cols * n_cols));
 
    // Generate the initial x,y tables using the positional
    // index and crop the unused pixels from the maximum in
    // each dimension
    for (uint32_t i = 0; i < n_cols; i++) {
        // Each value in a row increments by one
        p_xp[i] = (float)i;
    }
    // Replicate the rows
    for (uint32_t j = 0; j < n_rows; j++) {
        memcpy(&p_xp[j * n_cols], p_xp, n_cols * sizeof(float));
    }
 
    for (uint32_t j = 0; j < n_rows; j++) {
        // Each row is one more than the last
        float value = (float)j;
        for (uint32_t i = 0; i < n_cols; i++) {
            // Every value in a row is the same
            p_yp[j * n_cols + i] = value;
        }
    }
 
    UndistortPoints(p_xp, p_yp, p_xp, p_yp, p_intr_data, iter, n_rows, n_cols,
                    row_bin_factor, col_bin_factor);
 
    for (uint32_t j = 0; j < n_rows; j++) {
        for (uint32_t i = 0; i < n_cols; i++) {
            int idx = j * n_cols + i;
            float xp = p_xp[idx];
            float yp = p_yp[idx];
            p_z[idx] = sqrtf(xp * xp + yp * yp + 1);
            //Check for invalid values
            if (isnan(xp) || isnan(yp) || isnan(p_z[idx]) || p_z[idx] == 0) {
                // Calculate the coordinates relative to the center pixel
                float ix = (float)i - cx;
                float iy = (float)j - cy;
                float r = sqrt(ix * ix + iy * iy);
                // Find the minimum radius with an invalid number
                if (r < r_min) {
                    r_min = r;
                }
            }
        }
    }
    //Add a 2 pixel buffer
    r_min -= 2;
 
    //Filter for invalid pixels
    for (uint32_t j = 0; j < n_rows; j++) {
        for (uint32_t i = 0; i < n_cols; i++) {
            int idx = j * n_cols + i;
            float ix = (float)i - cx;
            float iy = (float)j - cy;
            float r = sqrt(ix * ix + iy * iy);
            if (r >= r_min) {
                // zero if the pixel is outside the valid radius
                p_xp[idx] = 0;
                p_yp[idx] = 0;
                p_z[idx] = 0;
            }
        }
    }
 
    // Add a 2 pixel buffer
    r_min -= 2;
 
    float *p_xfull = p_xp;
    float *p_yfull = p_yp;
    float *p_zfull = p_z;
 
    p_xp = (float *)malloc(n_out_rows * n_out_cols * sizeof(float));
    p_yp = (float *)malloc(n_out_rows * n_out_cols * sizeof(float));
    p_z = (float *)malloc(n_out_rows * n_out_cols * sizeof(float));
 
    for (uint32_t j = 0; j < n_out_rows; j++) {
        for (uint32_t i = 0; i < n_out_cols; i++) {
            int idx = (j + n_offset_rows) * n_cols + i + n_offset_cols;
            int crop_idx = j * n_out_cols + i;
            float x = p_xfull[idx];
            float y = p_yfull[idx];
            float z = p_zfull[idx];
            if (z != 0) {
                p_xp[crop_idx] = x / z;
                p_yp[crop_idx] = y / z;
                p_z[crop_idx] = 1 / z;
            }
        }
    }
 
    free(p_xfull);
    free(p_yfull);
    free(p_zfull);
 
    // Set the config pointers to the new buffers
    *pp_x_table = p_xp;
    *pp_y_table = p_yp;
    *pp_z_table = p_z;
 
    return 0;
}
 
uint32_t Algorithms::ComputeXYZ(const uint16_t *p_depth, XYZTable *p_xyz_data,
                                int16_t *p_xyz_image, uint32_t n_rows,
                                uint32_t n_cols) {
 
    for (int pixel_id = 0; pixel_id < n_rows * n_cols; pixel_id++) {
        p_xyz_image[3 * pixel_id + 0] = (int16_t)(floorf(
            p_xyz_data->p_x_table[pixel_id] * (float)p_depth[pixel_id] + 0.5f));
 
        p_xyz_image[3 * pixel_id + 1] = (int16_t)(floorf(
            p_xyz_data->p_y_table[pixel_id] * (float)p_depth[pixel_id] + 0.5f));
 
        p_xyz_image[3 * pixel_id + 2] = (int16_t)((
            p_xyz_data->p_z_table[pixel_id] * (float)p_depth[pixel_id] + 0.5f));
    }
 
    return 0;
}