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-rw-r--r--src/gen-image.c191
1 files changed, 188 insertions, 3 deletions
diff --git a/src/gen-image.c b/src/gen-image.c
index ae3d3cf..0ee9774 100644
--- a/src/gen-image.c
+++ b/src/gen-image.c
@@ -46,6 +46,8 @@ do { \
(b) = __tmp; \
} while (0)
+#define div_round_up(n, d) (((n) + (d) - 1) / (d))
+
enum format_type {
FORMAT_RGB,
FORMAT_YUV,
@@ -119,6 +121,7 @@ struct params {
enum histogram_type {
HISTOGRAM_HGO,
+ HISTOGRAM_HGT,
};
struct options {
@@ -141,6 +144,7 @@ struct options {
bool crop;
struct image_rect inputcrop;
enum histogram_type histo_type;
+ uint8_t histo_areas[12];
};
/* -----------------------------------------------------------------------------
@@ -1320,11 +1324,162 @@ static void histogram_compute_hgo(const struct image *image, void *histo)
}
}
+static void histogram_compute_hgt(const struct image *image, void *histo,
+ const uint8_t hue_areas[12])
+{
+ const uint8_t *data = image->data;
+ uint8_t hue_indices[256];
+ uint8_t smin = 255, smax = 0;
+ uint32_t sum = 0;
+ uint32_t hist[6][32];
+ unsigned int hue_index;
+ unsigned int x, y;
+ unsigned int h;
+
+ memset(hist, 0, sizeof(hist));
+
+ /*
+ * Precompute the hue region index for all possible hue values. The
+ * index starts at 0 for the overlapping region between hue areas 5
+ * and 0.
+ *
+ * Hue area 0 can wrap around the H value space (for example include
+ * values greater than 240 and lower than 30) depending on whether 0L
+ * is higher than 5U or lower than 0U.
+ *
+ * Area 0 Area 1 Area 2 Area 3 Area 4 Area 5 Area 0
+ * ________ ________ ________ ________ ________ ________ _____
+ * \ /| |\ /| |\ /| |\ /| |\ /| |\ /| |\ /|
+ * \ / | | \ / | | \ / | | \ / | | \ / | | \ / | | \ / |
+ * X | | X | | X | | X | | X | | X | | X |
+ * / \ | | / \ | | / \ | | / \ | | / \ | | / \ | | / \ |
+ * / \| |/ \| |/ \| |/ \| |/ \| |/ \| |/ \|
+ * 5U 0L 0U 1L 1U 2L 2U 3L 3U 4L 4U 5L 5U 0L
+ * RI ] 0 ] 1 ] 2 ] 3 ] 4 ] 5 ] 6 ] 7 ] 8 ] 9 ] 10 ] 11 ] 0 ] 1
+ *
+ * NW ..255><0.................................Hue Value..............................255><0.......
+ * W .......255><0.................................Hue Value..............................255><0..
+ *
+ * RI: Hue region index
+ * W: Area 0 wraps around the hue value space
+ * NW: Area 0 doesn't wrap around the hue value space
+ *
+ * Boundary values are included in the lower-value region.
+ */
+
+ /*
+ * The first hue value after 5U falls in region index 0. However, if
+ * 5U == 0L, areas 5 and 0 don't overlap, region index 0 is empty and
+ * the first hue value falls in region index 1.
+ *
+ * Process the ]5U, 255] range first, followed by the [0, 5U] range.
+ */
+ hue_index = hue_areas[11] == hue_areas[0] ? 1 : 0;
+
+ for (h = hue_areas[11] + 1; h <= 255; ++h) {
+ hue_indices[h] = hue_index;
+
+ if (h == hue_areas[hue_index])
+ hue_index++;
+ }
+
+ for (h = 0; h <= hue_areas[11]; ++h) {
+ hue_indices[h] = hue_index;
+
+ while (h == hue_areas[hue_index])
+ hue_index++;
+ }
+
+ /* Compute the histogram */
+ for (y = 0; y < image->height; ++y) {
+ for (x = 0; x < image->width; ++x) {
+ uint8_t rgb[3], hsv[3];
+ unsigned int hist_n;
+
+ rgb[0] = *data++;
+ rgb[1] = *data++;
+ rgb[2] = *data++;
+
+ hst_rgb_to_hsv(rgb, hsv);
+
+ smin = min(smin, hsv[1]);
+ smax = max(smax, hsv[1]);
+ sum += hsv[1];
+
+ /* Compute the coordinates of the histogram bucket */
+ hist_n = hsv[1] / 8;
+ hue_index = hue_indices[hsv[0]];
+
+ /*
+ * Attribute the H value to area(s). If the H value is
+ * inside one of the non-overlapping regions (hue_index
+ * is odd) the max weight (16) is attributed to the
+ * corresponding area. Otherwise the weight is split
+ * between the two adjacent areas based on the distance
+ * between the H value and the areas boundaries.
+ */
+ if (hue_index % 2) {
+ hist[hue_index/2][hist_n] += 16;
+ } else {
+ unsigned int dist, width, weight;
+ unsigned int hue_index1, hue_index2;
+ int hue1, hue2;
+
+ hue_index1 = hue_index ? hue_index - 1 : 11;
+ hue_index2 = hue_index;
+
+ hue1 = hue_areas[hue_index1];
+ hue2 = hue_areas[hue_index2];
+
+ /*
+ * Calculate the width to be attributed to the
+ * left area. Handle the wraparound through
+ * modulo arithmetic.
+ */
+ dist = (hue2 - hsv[0]) & 255;
+ width = (hue2 - hue1) & 255;
+ weight = div_round_up(dist * 16, width);
+
+ /* Split weight between the two areas */
+ hist[hue_index1/2][hist_n] += weight;
+ hist[hue_index2/2][hist_n] += 16 - weight;
+ }
+ }
+ }
+
+ /* Format the data buffer */
+
+ /* Min/Max Value of S Components */
+ *(uint8_t *)histo++ = smin;
+ *(uint8_t *)histo++ = 0;
+ *(uint8_t *)histo++ = smax;
+ *(uint8_t *)histo++ = 0;
+
+ /* Sum of S Components */
+ *(uint32_t *)histo = sum;
+ histo += 4;
+
+ /* Weighted Frequency of Hue Area-m and Saturation Area-n */
+ for (x = 0; x < 6; x++) {
+ for (y = 0; y < 32; y++) {
+ *(uint32_t *)histo = hist[x][y];
+ histo += 4;
+ }
+ }
+}
+
#define HISTOGRAM_HGO_SIZE (3*4 + 3*4 + 3*64*4)
+#define HISTOGRAM_HGT_SIZE (1*4 + 1*4 + 6*32*4)
static int histogram(const struct image *image, const char *filename,
- enum histogram_type type)
+ enum histogram_type type, const uint8_t hgt_hue_areas[12])
{
+ /*
+ * Data must be big enough to contain the largest possible histogram.
+ *
+ * HGO: (3 + 3 + 3*64) * 4 = 792
+ * HGT: (1 + 1 + 6*32) * 4 = 776
+ */
uint8_t data[HISTOGRAM_HGO_SIZE];
size_t size;
int ret;
@@ -1335,6 +1490,10 @@ static int histogram(const struct image *image, const char *filename,
size = HISTOGRAM_HGO_SIZE;
histogram_compute_hgo(image, data);
break;
+ case HISTOGRAM_HGT:
+ size = HISTOGRAM_HGT_SIZE;
+ histogram_compute_hgt(image, data, hgt_hue_areas);
+ break;
default:
printf("Unknown histogram type\n");
return -EINVAL;
@@ -1497,7 +1656,8 @@ static int process(const struct options *options)
/* Compute the histogram */
if (options->histo_filename) {
- ret = histogram(input, options->histo_filename, options->histo_type);
+ ret = histogram(input, options->histo_filename, options->histo_type,
+ options->histo_areas);
if (ret)
goto done;
}
@@ -1666,7 +1826,11 @@ static void usage(const char *argv0)
printf("-h, --help Show this help screen\n");
printf(" --hflip Flip the image horizontally\n");
printf("-H, --histogram file Compute histogram on the output image and store it to file\n");
- printf(" --histogram-type type Set the histogram type. Valid values are hgo.\n");
+ printf(" --histogram-areas areas Configure the HGT histogram hue areas.\n");
+ printf(" Must be specified for HGT histograms.\n");
+ printf(" Areas are expressed as a comma-separated list of\n");
+ printf(" lower and upper boundaries for areas 0 to 5 ([0-255])\n");
+ printf(" --histogram-type type Set the histogram type. Valid values are hgo and hgt.\n");
printf(" Defaults to hgo if not specified\n");
printf("-i, --in-format format Set the input image format\n");
printf(" Defaults to RGB24 if not specified\n");
@@ -1694,6 +1858,7 @@ static void list_formats(void)
#define OPT_VFLIP 257
#define OPT_CROP 258
#define OPT_HISTOGRAM_TYPE 259
+#define OPT_HISTOGRAM_AREAS 260
static struct option opts[] = {
{"alpha", 1, 0, 'a'},
@@ -1705,6 +1870,7 @@ static struct option opts[] = {
{"help", 0, 0, 'h'},
{"hflip", 0, 0, OPT_HFLIP},
{"histogram", 1, 0, 'H'},
+ {"histogram-areas", 1, 0, OPT_HISTOGRAM_AREAS},
{"histogram-type", 1, 0, OPT_HISTOGRAM_TYPE},
{"in-format", 1, 0, 'i'},
{"lut", 1, 0, 'l'},
@@ -2000,12 +2166,31 @@ static int parse_args(struct options *options, int argc, char *argv[])
case OPT_HISTOGRAM_TYPE:
if (!strcmp(optarg, "hgo")) {
options->histo_type = HISTOGRAM_HGO;
+ } else if (!strcmp(optarg, "hgt")) {
+ options->histo_type = HISTOGRAM_HGT;
} else {
printf("Invalid histogram type '%s'\n", optarg);
return 1;
}
break;
+ case OPT_HISTOGRAM_AREAS: {
+ int matched;
+
+ matched = sscanf(optarg, "%hhu,%hhu,%hhu,%hhu,%hhu,%hhu,%hhu,%hhu,%hhu,%hhu,%hhu,%hhu",
+ &options->histo_areas[0], &options->histo_areas[1],
+ &options->histo_areas[2], &options->histo_areas[3],
+ &options->histo_areas[4], &options->histo_areas[5],
+ &options->histo_areas[6], &options->histo_areas[7],
+ &options->histo_areas[8], &options->histo_areas[9],
+ &options->histo_areas[10], &options->histo_areas[11]);
+ if (matched != 12) {
+ printf("Invalid hgt hue areas '%s'\n", optarg);
+ return 1;
+ }
+ break;
+ }
+
default:
printf("Invalid option -%c\n", c);
printf("Run %s -h for help.\n", argv[0]);
generated by cgit v1.2.3 (git 2.25.1) at 2024-05-18 03:57:43 +0000