Create Index of Pixels combined rgb values into a unit and quantify number pixels found in an image

Pixel_Table.c

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

struct Pixel {
    unsigned char r;
    unsigned char g;
    unsigned char b;
};

struct Pixel_Total {
    int value;
    int quantity;
};

struct Pixel_Table {
    struct Pixel_Total* totals;
    int length;
};

void find_or_realloc(struct Pixel_Table*, struct Pixel);

int main(void) {
    // Make some test data
    struct Pixel pixel1 = {1, 2, 3};
    struct Pixel pixel2 = {4, 5, 6};
    struct Pixel pixel3 = {1, 2, 3};
    struct Pixel pixel4 = {10, 11, 12};
    struct Pixel pixel5 = {4, 5, 6};
    
    // get some memory
    struct Pixel_Table table = {calloc(2, sizeof(struct Pixel_Total)), 2};
    
    find_or_realloc(&table, pixel1);
    find_or_realloc(&table, pixel2);
    find_or_realloc(&table, pixel3);
    find_or_realloc(&table, pixel4);
    find_or_realloc(&table, pixel5);

    // Check the data
    printf("Pixel 1 rbg = {%i, %i, %i} | Unit Value = %i\n",
	   pixel1.r, pixel1.g, pixel1.b, pixel1.r + (pixel1.g << 8) + (pixel1.b << 16));
    printf("Pixel 2 rbg = {%i, %i, %i} | Unit Value = %i\n",
	   pixel2.r, pixel2.g, pixel2.b, pixel2.r + (pixel2.g << 8) + (pixel2.b << 16));
    printf("Pixel 3 rbg = {%i, %i, %i} | Unit Value = %i\n",
	   pixel3.r, pixel3.g, pixel3.b, pixel3.r + (pixel3.g << 8) + (pixel3.b << 16));
    printf("Pixel 4 rbg = {%i, %i, %i} | Unit Value = %i\n",
	   pixel4.r, pixel4.g, pixel4.b, pixel4.r + (pixel4.g << 8) + (pixel4.b << 16));
    printf("Pixel 5 rbg = {%i, %i, %i} | Unit Value = %i\n",
	   pixel5.r, pixel5.g, pixel5.b, pixel5.r + (pixel5.g << 8) + (pixel5.b << 16));
    printf("\nAnd now the table\n");
    printf("table 1 value = %i | table 1 quantity = %i\n", table.totals[0].value, table.totals[0].quantity);
    printf("table 2 value = %i | table 2 quantity = %i\n", table.totals[1].value, table.totals[1].quantity);
    printf("table 3 value = %i | table 3 quantity = %i\n", table.totals[2].value, table.totals[2].quantity);
    printf("table 4 value = %i | table 4 quantity = %i\n", table.totals[3].value, table.totals[3].quantity);
    // clean up
    free(table.totals);
    return 0;
}

void find_or_realloc(struct Pixel_Table* p_table, struct Pixel p) {
    char found = 0;
    struct Pixel_Table t = *p_table;

    // new_value is the summation of all rgb values stuffed into one unit
    int new_value = p.r + (p.g << 8) + (p.b << 16);

    for(int i = 0; i < t.length; i++) {
	if(t.totals[i].value == new_value || (new_value == 0 && t.totals[i].value == 0)) {
	    t.totals[i].quantity++;
	    found = 1;
	    break;
	}
	else if(t.totals[i].value == 0 && new_value != 0) {
	    t.totals[i].value = new_value;
	    t.totals[i].quantity++;
	    found = 1;
	    break;
	}
    }

    // If we didn't find the value, or don't have space for a new pixel value
    // get more memory
    if(!found) {
	int new_length = t.length + 2;
	struct Pixel_Total* new_totals = calloc(new_length, sizeof(struct Pixel_Total));

	// Copy the old array to the new
	memcpy(new_totals, t.totals, sizeof(struct Pixel_Total) * t.length);
	
	free(p_table->totals);
	p_table->totals = new_totals;
	p_table->totals[t.length].value = new_value;
	p_table->totals[t.length].quantity++;
	p_table->length = new_length;
    }

    // this could return a bool so your program knows if this function was successful
    // or maybe we have an issue with memory that fails. I didn't check if the memory
    // allocation was successful, but meh.
}