void adjust_sigma(Simulator *sim, int steps, double step_size,
double factor)
{
double original_sigma = sim->sigma;
double best_sigma = sim->sigma;
double best_error = barcode_error(sim);
for (int step = -steps; step <= steps; step++) {
if (step == 0)
continue;
sim->sigma = original_sigma + step * step_size;
if (sim->sigma < 1.0)
continue;
compute_kernel(sim);
convolve_1d(sim->kernel_width, sim->kernel,
sim->width, sim->guess, sim->blur, 0, sim->width);
double error = barcode_error(sim);
// printf("sigma=%.2f error=%.2f\n", sim->sigma, error);
if (error < best_error) {
best_error = error;
best_sigma = sim->sigma;
}
}
sim->sigma = best_sigma * factor + original_sigma * (1.0 - factor);
compute_kernel(sim);
convolve_1d(sim->kernel_width, sim->kernel,
sim->width, sim->guess, sim->blur, 0, sim->width);
}
int guess_digit(Simulator *sim, int *sections, int index,
int choices_count, char *choices)
{
// printf("guess_digit start=%d stop=%d\n", sections[0], sections[7]);
int start = sim->changes_count;
int best_choice = -1;
double best_error = UNKNOWN;
for (int choice = 0; choice < choices_count; choice++) {
encode_bits(sim->width, sim->black, sim->white, sim->guess,
sections, 7, choices[choice]);
convolve_1d(sim->kernel_width, sim->kernel,
sim->width, sim->guess, sim->blur,
sections[0], sections[7]);
double error = samples_error(sim, sections[0], sections[7]);
if (error < best_error) {
best_choice = choice;
best_error = error;
}
sim->changes[sim->changes_count].error = error;
sim->changes[sim->changes_count].index = index;
sim->changes[sim->changes_count].digit = choice;
sim->changes_count++;
}
// Make all changes relative to the best choice.
for (int i = start; i < sim->changes_count; i++)
sim->changes[i].error -= sim->changes[start + best_choice].error;
// Remove the best choice from the changes array.
if (best_choice < choices_count - 1)
sim->changes[start + best_choice] =
sim->changes[start + choices_count - 1];
sim->changes_count--;
return best_choice;
}
Rle<double>
convolve_1d(Rle<double> &rle,
std::vector<double> const& kernel,
bool rescale, double eps) {
std::vector<double> tmp = rle.expand();
std::vector<double> result = convolve_1d(tmp, kernel, rescale);
return Rle<double>(result, eps);
}
void simulate_range(Simulator *sim, int start, int stop)
{
// printf("simulate_range start=%d stop=%d\n", start, stop);
int x = start;
int next_section = 0;
while (next_section < 96 && x > sim->sections[next_section])
next_section++;
while (x < stop) {
// printf("start=%d x=%d stop=%d sections[%d]=%d\n",
// start, x, stop, next_section, sim->sections[next_section]);
if (next_section <= 0) { // Left shoulder.
for (; x < sim->sections[0]; x++)
sim->guess[x] = sim->white[x];
next_section = 1;
} else if (next_section <= 3) { // Left guard bars.
encode_bits(sim->width, sim->black, sim->white, sim->guess,
&sim->sections[0], 3, 0x5);
next_section = 4;
} else if (next_section <= 45) { // Left six digits.
int i = (next_section - 4) / 7;
encode_bits(sim->width, sim->black, sim->white, sim->guess,
&sim->sections[3 + 7 * i], 7,
LG[(int)sim->digits[1 + i]]);
next_section = 3 + 7 * i + 8;
} else if (next_section <= 50) { // Middle guard bars.
encode_bits(sim->width, sim->black, sim->white, sim->guess,
&sim->sections[45], 5, 0xa);
next_section = 51;
} else if (next_section <= 92) { // Right six digits.
int i = (next_section - 51) / 7;
encode_bits(sim->width, sim->black, sim->white, sim->guess,
&sim->sections[50 + 7 * i], 7,
R[(int)sim->digits[7 + i]]);
next_section = 50 + 7 * i + 8;
} else if (next_section <= 95) { // Right guard bars.
encode_bits(sim->width, sim->black, sim->white, sim->guess,
&sim->sections[92], 3, 0x5);
next_section = 96;
} else { // Right shoulder.
for (; x < stop; x++)
sim->guess[x] = sim->white[x];
break;
}
x = sim->sections[next_section - 1];
}
convolve_1d(sim->kernel_width, sim->kernel,
sim->width, sim->guess, sim->blur, start, stop);
}
void correct_errors(Simulator *sim, int max_changes, int max_count)
{
if (is_valid_barcode(sim->digits))
return;
qsort(sim->changes, sim->changes_count, sizeof(Change), compare_float);
// for (int i = 0; i < 10; i++)
// printf("error=%.6f index=%d digit=%d\n",
// changes[i].error, changes[i].index, changes[i].digit);
if (sim->changes_count > max_count)
sim->changes_count = max_count;
// Terminate search for valid candidate.
sim->changes[sim->changes_count].index = -1;
best_valid_barcode(sim->changes, max_changes, sim->digits);
encode_ean13(sim->width, sim->black, sim->white, sim->guess,
sim->sections, sim->digits);
convolve_1d(sim->kernel_width, sim->kernel,
sim->width, sim->guess, sim->blur, 0, sim->width);
sim->checksum = ean13_checksum(sim->digits);
}
void guess_digits(Simulator *sim)
{
// printf("guess_digits...\n");
sim->changes_count = 0;
sim->digits[0] = 0;
for (int i = 0; i < 6; i++) {
sim->digits[1 + i] =
guess_digit(sim, &sim->sections[3 + i * 7], 1 + i, i ? 20 : 10,
LG);
sim->digits[7 + i] =
guess_digit(sim, &sim->sections[50 + i * 7], 7 + i, 10, R);
}
encode_ean13(sim->width, sim->black, sim->white, sim->guess,
sim->sections, sim->digits);
convolve_1d(sim->kernel_width, sim->kernel,
sim->width, sim->guess, sim->blur, 0, sim->width);
sim->digits[0] = ean13_first_digit(sim->digits);
sim->checksum = ean13_checksum(sim->digits);
memcpy(sim->unchanged_digits, sim->digits, 13);
}
