Rushiraj Jawale / Mbed OS firmware_framework1

uart

Dependencies:   MAX32620FTHR USBDevice

img_utils.c@0:c62425b2f286, 18 months ago (annotated)

Committer:
rsjawale24
Date:
Sun Oct 16 15:35:01 2022 +0000
Revision:
0:c62425b2f286
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rsjawale24 0:c62425b2f286 1 /*******************************************************************************
rsjawale24 0:c62425b2f286 2 * Copyright (C) Maxim Integrated Products, Inc., All rights Reserved.
rsjawale24 0:c62425b2f286 3 *
rsjawale24 0:c62425b2f286 4 * This software is protected by copyright laws of the United States and
rsjawale24 0:c62425b2f286 5 * of foreign countries. This material may also be protected by patent laws
rsjawale24 0:c62425b2f286 6 * and technology transfer regulations of the United States and of foreign
rsjawale24 0:c62425b2f286 7 * countries. This software is furnished under a license agreement and/or a
rsjawale24 0:c62425b2f286 8 * nondisclosure agreement and may only be used or reproduced in accordance
rsjawale24 0:c62425b2f286 9 * with the terms of those agreements. Dissemination of this information to
rsjawale24 0:c62425b2f286 10 * any party or parties not specified in the license agreement and/or
rsjawale24 0:c62425b2f286 11 * nondisclosure agreement is expressly prohibited.
rsjawale24 0:c62425b2f286 12 *
rsjawale24 0:c62425b2f286 13 * The above copyright notice and this permission notice shall be included
rsjawale24 0:c62425b2f286 14 * in all copies or substantial portions of the Software.
rsjawale24 0:c62425b2f286 15 *
rsjawale24 0:c62425b2f286 16 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
rsjawale24 0:c62425b2f286 17 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
rsjawale24 0:c62425b2f286 18 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
rsjawale24 0:c62425b2f286 19 * IN NO EVENT SHALL MAXIM INTEGRATED BE LIABLE FOR ANY CLAIM, DAMAGES
rsjawale24 0:c62425b2f286 20 * OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
rsjawale24 0:c62425b2f286 21 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
rsjawale24 0:c62425b2f286 22 * OTHER DEALINGS IN THE SOFTWARE.
rsjawale24 0:c62425b2f286 23 *
rsjawale24 0:c62425b2f286 24 * Except as contained in this notice, the name of Maxim Integrated
rsjawale24 0:c62425b2f286 25 * Products, Inc. shall not be used except as stated in the Maxim Integrated
rsjawale24 0:c62425b2f286 26 * Products, Inc. Branding Policy.
rsjawale24 0:c62425b2f286 27 *
rsjawale24 0:c62425b2f286 28 * The mere transfer of this software does not imply any licenses
rsjawale24 0:c62425b2f286 29 * of trade secrets, proprietary technology, copyrights, patents,
rsjawale24 0:c62425b2f286 30 * trademarks, maskwork rights, or any other form of intellectual
rsjawale24 0:c62425b2f286 31 * property whatsoever. Maxim Integrated Products, Inc. retains all
rsjawale24 0:c62425b2f286 32 * ownership rights.
rsjawale24 0:c62425b2f286 33 *******************************************************************************
rsjawale24 0:c62425b2f286 34 */
rsjawale24 0:c62425b2f286 35
rsjawale24 0:c62425b2f286 36 #include "img_utils.h"
rsjawale24 0:c62425b2f286 37
rsjawale24 0:c62425b2f286 38 int getMaxPixelValue(const int pixels[], const unsigned int num_pixels)
rsjawale24 0:c62425b2f286 39 {
rsjawale24 0:c62425b2f286 40 int maxpixel=-99999;
rsjawale24 0:c62425b2f286 41 for (unsigned int i = 0; i < num_pixels; i++) {
rsjawale24 0:c62425b2f286 42 if (maxpixel < pixels[i]) {
rsjawale24 0:c62425b2f286 43 maxpixel = pixels[i];
rsjawale24 0:c62425b2f286 44 }
rsjawale24 0:c62425b2f286 45 }
rsjawale24 0:c62425b2f286 46 return maxpixel;
rsjawale24 0:c62425b2f286 47 }
rsjawale24 0:c62425b2f286 48
rsjawale24 0:c62425b2f286 49 int getMinPixelValue(const int pixels[], const unsigned int num_pixels)
rsjawale24 0:c62425b2f286 50 {
rsjawale24 0:c62425b2f286 51 int minpixel=99999;
rsjawale24 0:c62425b2f286 52 for (unsigned int i = 0; i < num_pixels; i++) {
rsjawale24 0:c62425b2f286 53 if (minpixel > pixels[i]) {
rsjawale24 0:c62425b2f286 54 minpixel = pixels[i];
rsjawale24 0:c62425b2f286 55 }
rsjawale24 0:c62425b2f286 56 }
rsjawale24 0:c62425b2f286 57 return minpixel;
rsjawale24 0:c62425b2f286 58 }
rsjawale24 0:c62425b2f286 59
rsjawale24 0:c62425b2f286 60 // Zero out pixels below threshold value. Returns the number of pixels above the threshold
rsjawale24 0:c62425b2f286 61 unsigned int zeroPixelsBelowThreshold(int pixels[], const unsigned int num_pixels, const int threshold)
rsjawale24 0:c62425b2f286 62 {
rsjawale24 0:c62425b2f286 63 int pixelsAboveThresholdCount = num_pixels;
rsjawale24 0:c62425b2f286 64 for (unsigned int i = 0; i < num_pixels; i++) {
rsjawale24 0:c62425b2f286 65 if (pixels[i] < threshold) {
rsjawale24 0:c62425b2f286 66 pixels[i] = 0;
rsjawale24 0:c62425b2f286 67 pixelsAboveThresholdCount--;
rsjawale24 0:c62425b2f286 68 }
rsjawale24 0:c62425b2f286 69 }
rsjawale24 0:c62425b2f286 70 return pixelsAboveThresholdCount;
rsjawale24 0:c62425b2f286 71 }
rsjawale24 0:c62425b2f286 72
rsjawale24 0:c62425b2f286 73 // Caller must keep static filtpixels array
rsjawale24 0:c62425b2f286 74 void filterLowPassPixels(int pixels[], float filtpixels[], const unsigned int num_pixels, const float alpha)
rsjawale24 0:c62425b2f286 75 {
rsjawale24 0:c62425b2f286 76 for (unsigned int i=0; i< num_pixels; i++) {
rsjawale24 0:c62425b2f286 77 filtpixels[i] = (1.0 - alpha) * filtpixels[i] + alpha * pixels[i];
rsjawale24 0:c62425b2f286 78 }
rsjawale24 0:c62425b2f286 79 for (unsigned int i=0; i< num_pixels; i++) {
rsjawale24 0:c62425b2f286 80 pixels[i] = (int)filtpixels[i];
rsjawale24 0:c62425b2f286 81 }
rsjawale24 0:c62425b2f286 82 }
rsjawale24 0:c62425b2f286 83
rsjawale24 0:c62425b2f286 84 // Implement background subtraction by subtracting long exponential smoothing average from a shorter one
rsjawale24 0:c62425b2f286 85 // (or simply the current pixel if alpha_short_avg is set to 1.0)
rsjawale24 0:c62425b2f286 86 // alpha_long_avg should be smaller than alpha_short_avg
rsjawale24 0:c62425b2f286 87 // Caller must keep static shart_avg_pixels[] and long_avg_pixels[]
rsjawale24 0:c62425b2f286 88 // The bigger alpha long is, the more aggressive the high pass filter.
rsjawale24 0:c62425b2f286 89 void subtractBackground(int pixels[], float short_avg_pixels[], float long_avg_pixels[], const unsigned int num_pixels, const float alpha_short_avg, const float alpha_long_avg)
rsjawale24 0:c62425b2f286 90 {
rsjawale24 0:c62425b2f286 91 for (unsigned int i=0; i< num_pixels; i++) {
rsjawale24 0:c62425b2f286 92 long_avg_pixels[i] = (1.0f - alpha_long_avg) * long_avg_pixels[i] + alpha_long_avg * pixels[i];
rsjawale24 0:c62425b2f286 93 }
rsjawale24 0:c62425b2f286 94 for (unsigned int i=0; i< num_pixels; i++) {
rsjawale24 0:c62425b2f286 95 short_avg_pixels[i] = (1.0f - alpha_short_avg) * short_avg_pixels[i] + alpha_short_avg * pixels[i];
rsjawale24 0:c62425b2f286 96 }
rsjawale24 0:c62425b2f286 97 for (unsigned int i=0; i< num_pixels; i++) {
rsjawale24 0:c62425b2f286 98 pixels[i] = short_avg_pixels[i] - (int)long_avg_pixels[i];
rsjawale24 0:c62425b2f286 99 }
rsjawale24 0:c62425b2f286 100 }
rsjawale24 0:c62425b2f286 101
rsjawale24 0:c62425b2f286 102 void calcCenterOfMass(const int pixels[], const unsigned int xres, const unsigned int yres, float *cmx, float *cmy, int *totalmass)
rsjawale24 0:c62425b2f286 103 {
rsjawale24 0:c62425b2f286 104 int cmx_numer=0, cmy_numer=0;
rsjawale24 0:c62425b2f286 105 for (unsigned int i = 0; i < xres*yres; i++) {
rsjawale24 0:c62425b2f286 106 cmx_numer += (i%xres)*pixels[i];
rsjawale24 0:c62425b2f286 107 cmy_numer += (i/xres)*pixels[i];
rsjawale24 0:c62425b2f286 108 *totalmass += pixels[i];
rsjawale24 0:c62425b2f286 109 }
rsjawale24 0:c62425b2f286 110 if (*totalmass == 0) {
rsjawale24 0:c62425b2f286 111 *totalmass = 1; // avoid NaN
rsjawale24 0:c62425b2f286 112 }
rsjawale24 0:c62425b2f286 113 *cmx = (float)cmx_numer/(float)(*totalmass);
rsjawale24 0:c62425b2f286 114 *cmy = (float)cmy_numer/(float)(*totalmass);
rsjawale24 0:c62425b2f286 115 }
rsjawale24 0:c62425b2f286 116
rsjawale24 0:c62425b2f286 117 void interpn(const int pixels[], int interp_pixels[], const int w, const int h, const int interpolation_factor)
rsjawale24 0:c62425b2f286 118 {
rsjawale24 0:c62425b2f286 119 int w2 = (w - 1) * interpolation_factor + 1;
rsjawale24 0:c62425b2f286 120 int h2 = (h - 1) * interpolation_factor + 1;
rsjawale24 0:c62425b2f286 121 int A, B, C, x, y;
rsjawale24 0:c62425b2f286 122 float x_ratio = 1.0f / (float)interpolation_factor;
rsjawale24 0:c62425b2f286 123 float y_ratio = 1.0f / (float)interpolation_factor;
rsjawale24 0:c62425b2f286 124
rsjawale24 0:c62425b2f286 125 // First stretch in x-direction, index through each pixel of destination array. Skip rows in destination array
rsjawale24 0:c62425b2f286 126 for (int i = 0; i < h; i++) {
rsjawale24 0:c62425b2f286 127 for (int j = 0; j < w2; j++) {
rsjawale24 0:c62425b2f286 128 x = (int)(x_ratio * j); // x index of original frame
rsjawale24 0:c62425b2f286 129 int index = i * w + x; // pixel index of original frame
rsjawale24 0:c62425b2f286 130 if (x == w - 1) // last pixel on right edge of original frame
rsjawale24 0:c62425b2f286 131 interp_pixels[i * w2 * interpolation_factor + j] = pixels[index]; // skip rows in dest array
rsjawale24 0:c62425b2f286 132 else {
rsjawale24 0:c62425b2f286 133 A = pixels[index];
rsjawale24 0:c62425b2f286 134 B = pixels[index + 1];
rsjawale24 0:c62425b2f286 135 float x_diff = (x_ratio * j) - x; // For 2x interpolation, will be 0, 1/2, 0, 1/2...
rsjawale24 0:c62425b2f286 136 interp_pixels[i * w2 * interpolation_factor + j] = (int)(A + (B - A) * x_diff); // skip rows in dest array
rsjawale24 0:c62425b2f286 137 }
rsjawale24 0:c62425b2f286 138 }
rsjawale24 0:c62425b2f286 139 }
rsjawale24 0:c62425b2f286 140 // Then stretch in y-direction, index through each pixel of destination array
rsjawale24 0:c62425b2f286 141 for (int i = 0; i < h2; i++) {
rsjawale24 0:c62425b2f286 142 for (int j = 0; j < w2; j++) {
rsjawale24 0:c62425b2f286 143 y = (int)(y_ratio * i); // y index of original frame
rsjawale24 0:c62425b2f286 144 int index = y * w2 * interpolation_factor + j; // pixel index of frame
rsjawale24 0:c62425b2f286 145 if (y == h - 1) // pixel on bottom of original frame
rsjawale24 0:c62425b2f286 146 interp_pixels[i * w2 + j] = interp_pixels[index];
rsjawale24 0:c62425b2f286 147 else {
rsjawale24 0:c62425b2f286 148 A = interp_pixels[index];
rsjawale24 0:c62425b2f286 149 C = interp_pixels[index + w2 * interpolation_factor];
rsjawale24 0:c62425b2f286 150 float y_diff = (y_ratio * i) - y;
rsjawale24 0:c62425b2f286 151 interp_pixels[i * w2 + j] = (int)(A + (C - A) * y_diff);
rsjawale24 0:c62425b2f286 152 }
rsjawale24 0:c62425b2f286 153 }
rsjawale24 0:c62425b2f286 154 }
rsjawale24 0:c62425b2f286 155 }