Updated quirc to v1.1 (2019); patched to remove compiler warnings

2020-06-03 02:13:07 +01:00
parent ca9da9d297
commit d358dd134e
6 changed files with 345 additions and 415 deletions
--- a/source/quirc/identify.c
+++ b/source/quirc/identify.c
@@ -14,6 +14,7 @@
 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */

+#include <limits.h>
 #include <string.h>
 #include <stdlib.h>
 #include <math.h>
@@ -98,8 +99,8 @@ static void perspective_map(const double *c,
 	double x = (c[0]*u + c[1]*v + c[2]) / den;
 	double y = (c[3]*u + c[4]*v + c[5]) / den;

-	ret->x = rint(x);
-	ret->y = rint(y);
+	ret->x = (int) rint(x);
+	ret->y = (int) rint(y);
 }

 static void perspective_unmap(const double *c,
@@ -121,234 +122,113 @@ static void perspective_unmap(const double *c,
 * Span-based floodfill routine
 */

+#define FLOOD_FILL_MAX_DEPTH		4096
+
 typedef void (*span_func_t)(void *user_data, int y, int left, int right);

-#if 0 // recursive flood fill
-
-#define FLOOD_FILL_MAX_DEPTH	4096
-
-struct flood_fill_params{
-	struct quirc *q;
-	int from;
-	int to;
-	span_func_t func;
-	void *user_data;
-};
-
-static struct flood_fill_params ffp;
-
-static void flood_fill_rec(int x, int y, int depth)
+static void flood_fill_seed(struct quirc *q, int x, int y, int from, int to,
+			    span_func_t func, void *user_data,
+			    int depth)
 {
 	int left = x;
 	int right = x;
 	int i;
-	quirc_pixel_t *row = ffp.q->pixels + y * ffp.q->w;
+	quirc_pixel_t *row = q->pixels + y * q->w;

-	if (!depth)
+	if (depth >= FLOOD_FILL_MAX_DEPTH)
 		return;

-	while (left > 0 && row[left - 1] == ffp.from)
+	while (left > 0 && row[left - 1] == from)
 		left--;

-	while (right < ffp.q->w - 1 && row[right + 1] == ffp.from)
+	while (right < q->w - 1 && row[right + 1] == from)
 		right++;

 	/* Fill the extent */
 	for (i = left; i <= right; i++)
-		row[i] = ffp.to;
+		row[i] = to;

-	if (ffp.func)
-		ffp.func(ffp.user_data, y, left, right);
+	if (func)
+		func(user_data, y, left, right);

 	/* Seed new flood-fills */
 	if (y > 0) {
-		row = ffp.q->pixels + (y - 1) * ffp.q->w;
+		row = q->pixels + (y - 1) * q->w;

 		for (i = left; i <= right; i++)
-			if (row[i] == ffp.from)
-				flood_fill_rec(i, y - 1, depth - 1);
+			if (row[i] == from)
+				flood_fill_seed(q, i, y - 1, from, to,
+						func, user_data, depth + 1);
 	}

-	if (y < ffp.q->h - 1) {
-		row = ffp.q->pixels + (y + 1) * ffp.q->w;
+	if (y < q->h - 1) {
+		row = q->pixels + (y + 1) * q->w;

 		for (i = left; i <= right; i++)
-			if (row[i] == ffp.from)
-				flood_fill_rec(i, y + 1, depth - 1);
+			if (row[i] == from)
+				flood_fill_seed(q, i, y + 1, from, to,
+						func, user_data, depth + 1);
 	}
 }

-static void flood_fill_seed(struct quirc *q, int x, int y, int from, int to,
-				span_func_t func, void *user_data)
-{
-	ffp.q = q;
-	ffp.from = from;
-	ffp.to = to;
-	ffp.func = func;
-	ffp.user_data = user_data;
-
-	flood_fill_rec(x, y, FLOOD_FILL_MAX_DEPTH);
-}
-
-#else // stacked flood fill
-
-#define FILL_STACK_CHUNK_SIZE 0x400
-
-struct fill_stack_chunk{
-	int x[FILL_STACK_CHUNK_SIZE];
-	int y[FILL_STACK_CHUNK_SIZE];
-	struct fill_stack_chunk *prev;
-};
-
-struct fill_stack{
-	struct fill_stack_chunk *last_chunk;
-	int index;
-};
-
-static void fill_stack_init(struct fill_stack *s){
-	s->last_chunk = NULL;
-}
-
-static int fill_stack_is_empty(struct fill_stack *s){
-	return s->last_chunk == NULL;
-}
-
-static void fill_stack_push(struct fill_stack *s, int x, int y){
-	struct fill_stack_chunk *c;
-	if(s->last_chunk != NULL && s->index < FILL_STACK_CHUNK_SIZE - 1){
-		c = s->last_chunk;
-		s->index++;
-	}else{
-		c = (struct fill_stack_chunk*)malloc(sizeof(struct fill_stack_chunk));
-		if(c == NULL){
-			return;
-		}
-		c->prev = s->last_chunk;
-		s->last_chunk = c;
-		s->index = 0;
-	}
-	c->x[s->index] = x;
-	c->y[s->index] = y;
-}
-
-static void fill_stack_pop(struct fill_stack *s, int *px, int *py){
-	struct fill_stack_chunk *c = s->last_chunk;
-	if(c == NULL){
-		return;
-	}
-	*px = c->x[s->index];
-	*py = c->y[s->index];
-	if(s->index > 0){
-		s->index--;
-	}else{
-		s->last_chunk = c->prev;
-		s->index = FILL_STACK_CHUNK_SIZE - 1;
-		free(c);
-	}
-}
-
-static void flood_fill_seed(struct quirc *q, int start_x, int start_y, int from, int to,
-				span_func_t func, void *user_data)
-{
-	struct fill_stack s;
-	fill_stack_init(&s);
-	fill_stack_push(&s, start_x, start_y);
-
-	do{
-		int x = 0, y = 0;
-		fill_stack_pop(&s, &x, &y);
-
-		int left = x, right = x, i;
-		quirc_pixel_t *row = q->pixels + y * q->w;
-
-		while (left > 0 && row[left - 1] == from)
-			left--;
-
-		while (right < q->w - 1 && row[right + 1] == from)
-			right++;
-
-		/* Fill the extent */
-		for (i = left; i <= right; i++)
-			row[i] = to;
-
-		if (func)
-			func(user_data, y, left, right);
-
-		/* Seed new flood-fills */
-		if (y > 0) {
-			row = q->pixels + (y - 1) * q->w;
-
-			for (i = left; i <= right; i++)
-				if (row[i] == from)
-					fill_stack_push(&s, i, y - 1);
-		}
-
-		if (y < q->h - 1) {
-			row = q->pixels + (y + 1) * q->w;
-
-			for (i = left; i <= right; i++)
-				if (row[i] == from)
-					fill_stack_push(&s, i, y + 1);
-		}
-	}while(!fill_stack_is_empty(&s));
-}
-#endif
-
 /************************************************************************
 * Adaptive thresholding
 */

-#define THRESHOLD_S_DEN		8
-#define THRESHOLD_T		5
-
-static void threshold(struct quirc *q)
+static uint8_t otsu(const struct quirc *q)
 {
-	int x, y;
-	int avg_w = 0;
-	int avg_u = 0;
-	int threshold_s = q->w / THRESHOLD_S_DEN;
-	quirc_pixel_t *row = q->pixels;
+	int numPixels = q->w * q->h;

-	for (y = 0; y < q->h; y++) {
-		int row_average[q->w];
-
-		memset(row_average, 0, sizeof(row_average));
-
-		for (x = 0; x < q->w; x++) {
-			int w, u;
-
-			if (y & 1) {
-				w = x;
-				u = q->w - 1 - x;
-			} else {
-				w = q->w - 1 - x;
-				u = x;
-			}
-
-			avg_w = (avg_w * (threshold_s - 1)) /
-				threshold_s + row[w];
-			avg_u = (avg_u * (threshold_s - 1)) /
-				threshold_s + row[u];
-
-			row_average[w] += avg_w;
-			row_average[u] += avg_u;
-		}
-
-		for (x = 0; x < q->w; x++) {
-			if (row[x] < row_average[x] *
-			    (100 - THRESHOLD_T) / (200 * threshold_s))
-				row[x] = QUIRC_PIXEL_BLACK;
-			else
-				row[x] = QUIRC_PIXEL_WHITE;
-		}
-
-		row += q->w;
+	// Calculate histogram
+	const int HISTOGRAM_SIZE = 256;
+	unsigned int histogram[HISTOGRAM_SIZE];
+	memset(histogram, 0, (HISTOGRAM_SIZE) * sizeof(unsigned int));
+	uint8_t* ptr = q->image;
+	int length = numPixels;
+	while (length--) {
+		uint8_t value = *ptr++;
+		histogram[value]++;
 	}
+
+	// Calculate weighted sum of histogram values
+	int sum = 0;
+	for (int i = 0; i < HISTOGRAM_SIZE; ++i) {
+		sum += i * histogram[i];
+	}
+
+	// Compute threshold
+	int sumB = 0;
+	int q1 = 0;
+	double max = 0;
+	uint8_t threshold = 0;
+	for (int i = 0; i < HISTOGRAM_SIZE; ++i) {
+		// Weighted background
+		q1 += histogram[i];
+		if (q1 == 0)
+			continue;
+
+		// Weighted foreground
+		const int q2 = numPixels - q1;
+		if (q2 == 0)
+			break;
+
+		sumB += i * histogram[i];
+		const double m1 = (double)sumB / q1;
+		const double m2 = ((double)sum - sumB) / q2;
+		const double m1m2 = m1 - m2;
+		const double variance = m1m2 * m1m2 * q1 * q2;
+		if (variance >= max) {
+			threshold = i;
+			max = variance;
+		}
+	}
+
+	return threshold;
 }

 static void area_count(void *user_data, int y, int left, int right)
 {
-	(void)y;
+    (void)y;
 	((struct quirc_region *)user_data)->count += right - left + 1;
 }

@@ -381,7 +261,7 @@ static int region_code(struct quirc *q, int x, int y)
 	box->seed.y = y;
 	box->capstone = -1;

-	flood_fill_seed(q, x, y, pixel, region, area_count, box);
+	flood_fill_seed(q, x, y, pixel, region, area_count, box, 0);

 	return region;
 }
@@ -451,7 +331,7 @@ static void find_region_corners(struct quirc *q,
 	psd.scores[0] = -1;
 	flood_fill_seed(q, region->seed.x, region->seed.y,
 			rcode, QUIRC_PIXEL_BLACK,
-			find_one_corner, &psd);
+			find_one_corner, &psd, 0);

 	psd.ref.x = psd.corners[0].x - psd.ref.x;
 	psd.ref.y = psd.corners[0].y - psd.ref.y;
@@ -469,7 +349,7 @@ static void find_region_corners(struct quirc *q,

 	flood_fill_seed(q, region->seed.x, region->seed.y,
 			QUIRC_PIXEL_BLACK, rcode,
-			find_other_corners, &psd);
+			find_other_corners, &psd, 0);
 }

 static void record_capstone(struct quirc *q, int ring, int stone)
@@ -542,7 +422,7 @@ static void finder_scan(struct quirc *q, int y)
 {
 	quirc_pixel_t *row = q->pixels + y * q->w;
 	int x;
-	int last_color;
+	int last_color = 0;
 	int run_length = 0;
 	int run_count = 0;
 	int pb[5];
@@ -888,7 +768,7 @@ static int fitness_all(const struct quirc *q, int index)

 	/* Check alignment patterns */
 	ap_count = 0;
-	while (info->apat[ap_count])
+	while ((ap_count < QUIRC_MAX_ALIGNMENT) && info->apat[ap_count])
 		ap_count++;

 	for (i = 1; i + 1 < ap_count; i++) {
@@ -974,7 +854,7 @@ static void rotate_capstone(struct quirc_capstone *cap,
 	struct quirc_point copy[4];
 	int j;
 	int best = 0;
-	int best_score = 0;
+	int best_score = INT_MAX;

 	for (j = 0; j < 4; j++) {
 		struct quirc_point *p = &cap->corners[j];
@@ -1082,10 +962,10 @@ static void record_qr_grid(struct quirc *q, int a, int b, int c)

 			flood_fill_seed(q, reg->seed.x, reg->seed.y,
 					qr->align_region, QUIRC_PIXEL_BLACK,
-					NULL, NULL);
+					NULL, NULL, 0);
 			flood_fill_seed(q, reg->seed.x, reg->seed.y,
 					QUIRC_PIXEL_BLACK, qr->align_region,
-					find_leftmost_to_line, &psd);
+					find_leftmost_to_line, &psd, 0);
 		}
 	}

@@ -1191,17 +1071,18 @@ static void test_grouping(struct quirc *q, int i)
 	test_neighbours(q, i, &hlist, &vlist);
 }

-static void pixels_setup(struct quirc *q)
+static void pixels_setup(struct quirc *q, uint8_t threshold)
 {
-	if (sizeof(*q->image) == sizeof(*q->pixels)) {
+	if (QUIRC_PIXEL_ALIAS_IMAGE) {
 		q->pixels = (quirc_pixel_t *)q->image;
-	} else {
-		int x, y;
-		for (y = 0; y < q->h; y++) {
-			for (x = 0; x < q->w; x++) {
-				q->pixels[y * q->w + x] = q->image[y * q->w + x];
-			}
-		}
+	}
+
+	uint8_t* source = q->image;
+	quirc_pixel_t* dest = q->pixels;
+	int length = q->w * q->h;
+	while (length--) {
+		uint8_t value = *source++;
+		*dest++ = (value < threshold) ? QUIRC_PIXEL_BLACK : QUIRC_PIXEL_WHITE;
 	}
 }

@@ -1223,8 +1104,8 @@ void quirc_end(struct quirc *q)
 {
 	int i;

-	pixels_setup(q);
-	threshold(q);
+	uint8_t threshold = otsu(q);
+	pixels_setup(q, threshold);

 	for (i = 0; i < q->h; i++)
 		finder_scan(q, i);