[FFmpeg-cvslog] avfilter/vf_colorbalance: add option to preserve lightness
Paul B Mahol
git at videolan.org
Wed Nov 13 14:09:38 EET 2019
ffmpeg | branch: master | Paul B Mahol <onemda at gmail.com> | Wed Nov 13 12:26:18 2019 +0100| [d19fdc83b35c66a9eada41dfb8c1e28076d73f1b] | committer: Paul B Mahol
avfilter/vf_colorbalance: add option to preserve lightness
> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=d19fdc83b35c66a9eada41dfb8c1e28076d73f1b
---
doc/filters.texi | 3 +
libavfilter/vf_colorbalance.c | 161 ++++++++++++++++++++++++++++++------------
2 files changed, 118 insertions(+), 46 deletions(-)
diff --git a/doc/filters.texi b/doc/filters.texi
index 6800124574..9268c33e30 100644
--- a/doc/filters.texi
+++ b/doc/filters.texi
@@ -7080,6 +7080,9 @@ Adjust red, green and blue midtones (medium pixels).
Adjust red, green and blue highlights (brightest pixels).
Allowed ranges for options are @code{[-1.0, 1.0]}. Defaults are @code{0}.
+
+ at item pl
+Preserve lightness when changing color balance. Default is disabled.
@end table
@subsection Examples
diff --git a/libavfilter/vf_colorbalance.c b/libavfilter/vf_colorbalance.c
index eb870ac2ad..e2e380174d 100644
--- a/libavfilter/vf_colorbalance.c
+++ b/libavfilter/vf_colorbalance.c
@@ -46,9 +46,11 @@ typedef struct ColorBalanceContext {
Range cyan_red;
Range magenta_green;
Range yellow_blue;
+ int preserve_lightness;
uint8_t rgba_map[4];
int depth;
+ int max;
int step;
int (*color_balance)(AVFilterContext *ctx, void *arg, int jobnr, int nb_jobs);
@@ -66,6 +68,7 @@ static const AVOption colorbalance_options[] = {
{ "rh", "set red highlights", OFFSET(cyan_red.highlights), AV_OPT_TYPE_DOUBLE, {.dbl=0}, -1, 1, FLAGS },
{ "gh", "set green highlights", OFFSET(magenta_green.highlights), AV_OPT_TYPE_DOUBLE, {.dbl=0}, -1, 1, FLAGS },
{ "bh", "set blue highlights", OFFSET(yellow_blue.highlights), AV_OPT_TYPE_DOUBLE, {.dbl=0}, -1, 1, FLAGS },
+ { "pl", "preserve lightness", OFFSET(preserve_lightness), AV_OPT_TYPE_BOOL, {.i64=0}, 0, 1, FLAGS },
{ NULL }
};
@@ -95,14 +98,10 @@ static int query_formats(AVFilterContext *ctx)
return ff_set_common_formats(ctx, fmts_list);
}
-static int get_component(int c, int depth, double l,
- double s, double m, double h)
+static double get_component(double v, double l,
+ double s, double m, double h)
{
const double a = 4, b = 0.333, scale = 0.7;
- const double max = (1 << depth) - 1;
- double v = c / max;
-
- l /= max;
s *= av_clipd((b - l) * a + 0.5, 0, 1) * scale;
m *= av_clipd((l - b) * a + 0.5, 0, 1) * av_clipd((1.0 - l - b) * a + 0.5, 0, 1) * scale;
@@ -111,10 +110,49 @@ static int get_component(int c, int depth, double l,
v += s;
v += m;
v += h;
- v = av_clipd(v, 0, 1);
- c = v * max;
- return av_clip_uintp2_c(c, depth);
+ return av_clipd(v, 0, 1);
+}
+
+static double hfun(double n, double h, double s, double l)
+{
+ double a = s * FFMIN(l, 1. - l);
+ double k = fmod(n + h / 30., 12.);
+
+ return av_clipd(l - a * FFMAX(FFMIN3(k - 3, 9 - k, 1), -1.), 0, 1);
+}
+
+static void preservel(double *r, double *g, double *b, double l)
+{
+ double max = FFMAX3(*r, *g, *b);
+ double min = FFMIN3(*r, *g, *b);
+ double h, s;
+
+ l *= 0.5;
+
+ if (*r == *g && *g == *b) {
+ h = 0.;
+ } else if (max == *r) {
+ h = 60. * (0. + (*g - *b) / (max - min));
+ } else if (max == *g) {
+ h = 60. * (2. + (*b - *r) / (max - min));
+ } else if (max == *b) {
+ h = 60. * (4. + (*r - *g) / (max - min));
+ } else {
+ h = 0.;
+ }
+ if (h < 0.)
+ h += 360.;
+
+ if (max == 0. || min == 1.) {
+ s = 0.;
+ } else {
+ s = (max - min) / (1. - FFABS(2. * l - 1));
+ }
+
+ *r = hfun(0, h, s, l);
+ *g = hfun(8, h, s, l);
+ *b = hfun(4, h, s, l);
}
static int color_balance8_p(AVFilterContext *ctx, void *arg, int jobnr, int nb_jobs)
@@ -133,19 +171,26 @@ static int color_balance8_p(AVFilterContext *ctx, void *arg, int jobnr, int nb_j
uint8_t *dstb = out->data[1] + slice_start * out->linesize[1];
uint8_t *dstr = out->data[2] + slice_start * out->linesize[2];
uint8_t *dsta = out->data[3] + slice_start * out->linesize[3];
- const int depth = s->depth;
+ const double max = s->max;
int i, j;
for (i = slice_start; i < slice_end; i++) {
for (j = 0; j < out->width; j++) {
- const int r = srcr[j];
- const int g = srcg[j];
- const int b = srcb[j];
- const int l = FFMAX3(r, g, b) + FFMIN3(r, g, b);
-
- dstr[j] = get_component(r, depth, l, s->cyan_red.shadows, s->cyan_red.midtones, s->cyan_red.highlights);
- dstg[j] = get_component(g, depth, l, s->magenta_green.shadows, s->magenta_green.midtones, s->magenta_green.highlights);
- dstb[j] = get_component(b, depth, l, s->yellow_blue.shadows, s->yellow_blue.midtones, s->yellow_blue.highlights);
+ double r = srcr[j] / max;
+ double g = srcg[j] / max;
+ double b = srcb[j] / max;
+ const double l = FFMAX3(r, g, b) + FFMIN3(r, g, b);
+
+ r = get_component(r, l, s->cyan_red.shadows, s->cyan_red.midtones, s->cyan_red.highlights);
+ g = get_component(g, l, s->magenta_green.shadows, s->magenta_green.midtones, s->magenta_green.highlights);
+ b = get_component(b, l, s->yellow_blue.shadows, s->yellow_blue.midtones, s->yellow_blue.highlights);
+
+ if (s->preserve_lightness)
+ preservel(&r, &g, &b, l);
+
+ dstr[j] = av_clip_uint8(r * max);
+ dstg[j] = av_clip_uint8(g * max);
+ dstb[j] = av_clip_uint8(b * max);
if (in != out && out->linesize[3])
dsta[j] = srca[j];
}
@@ -180,18 +225,26 @@ static int color_balance16_p(AVFilterContext *ctx, void *arg, int jobnr, int nb_
uint16_t *dstr = (uint16_t *)out->data[2] + slice_start * out->linesize[2] / 2;
uint16_t *dsta = (uint16_t *)out->data[3] + slice_start * out->linesize[3] / 2;
const int depth = s->depth;
+ const double max = s->max;
int i, j;
for (i = slice_start; i < slice_end; i++) {
for (j = 0; j < out->width; j++) {
- const int r = srcr[j];
- const int g = srcg[j];
- const int b = srcb[j];
- const int l = FFMAX3(r, g, b) + FFMIN3(r, g, b);
-
- dstr[j] = get_component(r, depth, l, s->cyan_red.shadows, s->cyan_red.midtones, s->cyan_red.highlights);
- dstg[j] = get_component(g, depth, l, s->magenta_green.shadows, s->magenta_green.midtones, s->magenta_green.highlights);
- dstb[j] = get_component(b, depth, l, s->yellow_blue.shadows, s->yellow_blue.midtones, s->yellow_blue.highlights);
+ double r = srcr[j] / max;
+ double g = srcg[j] / max;
+ double b = srcb[j] / max;
+ const double l = (FFMAX3(r, g, b) + FFMIN3(r, g, b));
+
+ r = get_component(r, l, s->cyan_red.shadows, s->cyan_red.midtones, s->cyan_red.highlights);
+ g = get_component(g, l, s->magenta_green.shadows, s->magenta_green.midtones, s->magenta_green.highlights);
+ b = get_component(b, l, s->yellow_blue.shadows, s->yellow_blue.midtones, s->yellow_blue.highlights);
+
+ if (s->preserve_lightness)
+ preservel(&r, &g, &b, l);
+
+ dstr[j] = av_clip_uintp2_c(r * max, depth);
+ dstg[j] = av_clip_uintp2_c(g * max, depth);
+ dstb[j] = av_clip_uintp2_c(b * max, depth);
if (in != out && out->linesize[3])
dsta[j] = srca[j];
}
@@ -223,7 +276,7 @@ static int color_balance8(AVFilterContext *ctx, void *arg, int jobnr, int nb_job
const uint8_t goffset = s->rgba_map[G];
const uint8_t boffset = s->rgba_map[B];
const uint8_t aoffset = s->rgba_map[A];
- const int depth = s->depth;
+ const double max = s->max;
const int step = s->step;
uint8_t *dstrow;
int i, j;
@@ -234,14 +287,21 @@ static int color_balance8(AVFilterContext *ctx, void *arg, int jobnr, int nb_job
uint8_t *dst = dstrow;
for (j = 0; j < outlink->w * step; j += step) {
- const int r = src[j + roffset];
- const int g = src[j + goffset];
- const int b = src[j + boffset];
- const int l = FFMAX3(r, g, b) + FFMIN3(r, g, b);
-
- dst[j + roffset] = get_component(r, depth, l, s->cyan_red.shadows, s->cyan_red.midtones, s->cyan_red.highlights);
- dst[j + goffset] = get_component(g, depth, l, s->magenta_green.shadows, s->magenta_green.midtones, s->magenta_green.highlights);
- dst[j + boffset] = get_component(b, depth, l, s->yellow_blue.shadows, s->yellow_blue.midtones, s->yellow_blue.highlights);
+ double r = src[j + roffset] / max;
+ double g = src[j + goffset] / max;
+ double b = src[j + boffset] / max;
+ const double l = (FFMAX3(r, g, b) + FFMIN3(r, g, b));
+
+ r = get_component(r, l, s->cyan_red.shadows, s->cyan_red.midtones, s->cyan_red.highlights);
+ g = get_component(g, l, s->magenta_green.shadows, s->magenta_green.midtones, s->magenta_green.highlights);
+ b = get_component(b, l, s->yellow_blue.shadows, s->yellow_blue.midtones, s->yellow_blue.highlights);
+
+ if (s->preserve_lightness)
+ preservel(&r, &g, &b, l);
+
+ dst[j + roffset] = av_clip_uint8(r * max);
+ dst[j + goffset] = av_clip_uint8(g * max);
+ dst[j + boffset] = av_clip_uint8(b * max);
if (in != out && step == 4)
dst[j + aoffset] = src[j + aoffset];
}
@@ -269,6 +329,7 @@ static int color_balance16(AVFilterContext *ctx, void *arg, int jobnr, int nb_jo
const uint8_t aoffset = s->rgba_map[A];
const int step = s->step / 2;
const int depth = s->depth;
+ const double max = s->max;
uint16_t *dstrow;
int i, j;
@@ -278,14 +339,21 @@ static int color_balance16(AVFilterContext *ctx, void *arg, int jobnr, int nb_jo
uint16_t *dst = dstrow;
for (j = 0; j < outlink->w * step; j += step) {
- const int r = src[j + roffset];
- const int g = src[j + goffset];
- const int b = src[j + boffset];
- const int l = FFMAX3(r, g, b) + FFMIN3(r, g, b);
-
- dst[j + roffset] = get_component(r, depth, l, s->cyan_red.shadows, s->cyan_red.midtones, s->cyan_red.highlights);
- dst[j + goffset] = get_component(g, depth, l, s->magenta_green.shadows, s->magenta_green.midtones, s->magenta_green.highlights);
- dst[j + boffset] = get_component(b, depth, l, s->yellow_blue.shadows, s->yellow_blue.midtones, s->yellow_blue.highlights);
+ double r = src[j + roffset] / max;
+ double g = src[j + goffset] / max;
+ double b = src[j + boffset] / max;
+ const double l = (FFMAX3(r, g, b) + FFMIN3(r, g, b));
+
+ r = get_component(r, l, s->cyan_red.shadows, s->cyan_red.midtones, s->cyan_red.highlights);
+ g = get_component(g, l, s->magenta_green.shadows, s->magenta_green.midtones, s->magenta_green.highlights);
+ b = get_component(b, l, s->yellow_blue.shadows, s->yellow_blue.midtones, s->yellow_blue.highlights);
+
+ if (s->preserve_lightness)
+ preservel(&r, &g, &b, l);
+
+ dst[j + roffset] = av_clip_uintp2_c(r * max, depth);
+ dst[j + goffset] = av_clip_uintp2_c(g * max, depth);
+ dst[j + boffset] = av_clip_uintp2_c(b * max, depth);
if (in != out && step == 4)
dst[j + aoffset] = src[j + aoffset];
}
@@ -303,16 +371,17 @@ static int config_output(AVFilterLink *outlink)
ColorBalanceContext *s = ctx->priv;
const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(outlink->format);
const int depth = desc->comp[0].depth;
- const int max = 1 << depth;
+ const int max = (1 << depth) - 1;
const int planar = av_pix_fmt_count_planes(outlink->format) > 1;
s->depth = depth;
+ s->max = max;
- if (max == 256 && planar) {
+ if (max == 255 && planar) {
s->color_balance = color_balance8_p;
} else if (planar) {
s->color_balance = color_balance16_p;
- } else if (max == 256) {
+ } else if (max == 255) {
s->color_balance = color_balance8;
} else {
s->color_balance = color_balance16;
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