[FFmpeg-devel] [PATCH 1/2] colorbalance filter
Paul B Mahol
onemda at gmail.com
Wed Apr 17 00:27:10 CEST 2013
On 4/16/13, Stefano Sabatini <stefasab at gmail.com> wrote:
> On date Tuesday 2013-04-16 12:23:30 +0000, Paul B Mahol encoded:
>> Signed-off-by: Paul B Mahol <onemda at gmail.com>
>> ---
>> doc/filters.texi | 27 +++++
>> libavfilter/Makefile | 1 +
>> libavfilter/allfilters.c | 1 +
>> libavfilter/vf_colorbalance.c | 222
>> ++++++++++++++++++++++++++++++++++++++++++
>> 4 files changed, 251 insertions(+)
>> create mode 100644 libavfilter/vf_colorbalance.c
>>
>> diff --git a/doc/filters.texi b/doc/filters.texi
>> index 5c2a54a..87811df 100644
>> --- a/doc/filters.texi
>> +++ b/doc/filters.texi
>> @@ -2051,6 +2051,33 @@
>> boxblur=luma_radius=min(h\,w)/10:luma_power=1:chroma_radius=min(cw\,ch)/10:chrom
>> @end example
>> @end itemize
>>
>> + at section colorbalance
>> +Modify intensity of primary colors (red, green and blue) of input image.
>> +
>> +The filter allows an image to be adjusted in the shadows, midtones or
>> highlights
>> +regions for the red-cyan, green-magenta or blue-yellow balance.
>> +
>> +The filter accepts the following options:
>> +
>> + at table @option
>> + at item rs
>> + at item gs
>> + at item bs
>> +Adjust red, green and blue shadows (darkest pixels).
>> +
>> + at item rm
>> + at item gm
>> + at item bm
>> +Adjust red, green and blue midtones (medium pixels).
>> +
>> + at item rh
>> + at item gh
>> + at item bh
>
>> +Adjust red, green and blue highlights (brightest pixels).
>> +
>> +Allowed range is from -100 to 100, default is 0.
>
> A range [-1, +1] seems more mathematically appealing (also specify
> this is a float number).
>
> Examples are welcome.
>
>> + at end table
>> +
>> @section colormatrix
>>
>> Convert color matrix.
>> diff --git a/libavfilter/Makefile b/libavfilter/Makefile
>> index 949972d..0927986 100644
>> --- a/libavfilter/Makefile
>> +++ b/libavfilter/Makefile
>> @@ -104,6 +104,7 @@ OBJS-$(CONFIG_BLACKDETECT_FILTER) +=
>> vf_blackdetect.o
>> OBJS-$(CONFIG_BLACKFRAME_FILTER) += vf_blackframe.o
>> OBJS-$(CONFIG_BLEND_FILTER) += vf_blend.o
>> OBJS-$(CONFIG_BOXBLUR_FILTER) += vf_boxblur.o
>> +OBJS-$(CONFIG_COLORBALANCE_FILTER) += vf_colorbalance.o
>> OBJS-$(CONFIG_COLORMATRIX_FILTER) += vf_colormatrix.o
>> OBJS-$(CONFIG_COPY_FILTER) += vf_copy.o
>> OBJS-$(CONFIG_CROP_FILTER) += vf_crop.o
>> diff --git a/libavfilter/allfilters.c b/libavfilter/allfilters.c
>> index 95bd270..bebbf2b 100644
>> --- a/libavfilter/allfilters.c
>> +++ b/libavfilter/allfilters.c
>> @@ -102,6 +102,7 @@ void avfilter_register_all(void)
>> REGISTER_FILTER(BLACKFRAME, blackframe, vf);
>> REGISTER_FILTER(BLEND, blend, vf);
>> REGISTER_FILTER(BOXBLUR, boxblur, vf);
>> + REGISTER_FILTER(COLORBALANCE, colorbalance, vf);
>> REGISTER_FILTER(COLORMATRIX, colormatrix, vf);
>> REGISTER_FILTER(COPY, copy, vf);
>> REGISTER_FILTER(CROP, crop, vf);
>> diff --git a/libavfilter/vf_colorbalance.c
>> b/libavfilter/vf_colorbalance.c
>> new file mode 100644
>> index 0000000..e9ecab6
>> --- /dev/null
>> +++ b/libavfilter/vf_colorbalance.c
>> @@ -0,0 +1,222 @@
>> +/*
>> + * Copyright (c) 2013 Paul B Mahol
>> + *
>> + * This file is part of FFmpeg.
>> + *
>> + * FFmpeg is free software; you can redistribute it and/or
>> + * modify it under the terms of the GNU Lesser General Public
>> + * License as published by the Free Software Foundation; either
>> + * version 2.1 of the License, or (at your option) any later version.
>> + *
>> + * FFmpeg is distributed in the hope that it will be useful,
>> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
>> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
>> + * Lesser General Public License for more details.
>> + *
>> + * You should have received a copy of the GNU Lesser General Public
>> + * License along with FFmpeg; if not, write to the Free Software
>> + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
>> 02110-1301 USA
>> + */
>> +
>> +#include "libavutil/opt.h"
>> +#include "libavutil/pixdesc.h"
>> +#include "avfilter.h"
>> +#include "drawutils.h"
>> +#include "formats.h"
>> +#include "internal.h"
>> +#include "video.h"
>> +
>> +typedef struct {
>> + double shadows;
>> + double midtones;
>> + double highlights;
>> +} Range;
>> +
>> +typedef struct {
>> + const AVClass *class;
>> + Range cyan_red;
>> + Range magenta_green;
>> + Range yellow_blue;
>> +
>> + uint8_t lookup[3][256];
>> +
>> + uint8_t rgba_map[4];
>> + int nb_components;
>> +} ColorBalanceContext;
>> +
>> +#define OFFSET(x) offsetof(ColorBalanceContext, x)
>> +#define FLAGS AV_OPT_FLAG_FILTERING_PARAM|AV_OPT_FLAG_VIDEO_PARAM
>> +static const AVOption colorbalance_options[] = {
>> + { "rs", "set red shadows", OFFSET(cyan_red.shadows),
>> AV_OPT_TYPE_DOUBLE, {.dbl=0}, -100, 100, FLAGS },
>> + { "gs", "set green shadows", OFFSET(magenta_green.shadows),
>> AV_OPT_TYPE_DOUBLE, {.dbl=0}, -100, 100, FLAGS },
>> + { "bs", "set blue shadows", OFFSET(yellow_blue.shadows),
>> AV_OPT_TYPE_DOUBLE, {.dbl=0}, -100, 100, FLAGS },
>> + { "rm", "set red midtones", OFFSET(cyan_red.midtones),
>> AV_OPT_TYPE_DOUBLE, {.dbl=0}, -100, 100, FLAGS },
>> + { "gm", "set green midtones", OFFSET(magenta_green.midtones),
>> AV_OPT_TYPE_DOUBLE, {.dbl=0}, -100, 100, FLAGS },
>> + { "bm", "set blue midtones", OFFSET(yellow_blue.midtones),
>> AV_OPT_TYPE_DOUBLE, {.dbl=0}, -100, 100, FLAGS },
>> + { "rh", "set red hightlights", OFFSET(cyan_red.highlights),
>> AV_OPT_TYPE_DOUBLE, {.dbl=0}, -100, 100, FLAGS },
>> + { "gh", "set green hightlights", OFFSET(magenta_green.highlights),
>> AV_OPT_TYPE_DOUBLE, {.dbl=0}, -100, 100, FLAGS },
>> + { "bh", "set blue hightlights", OFFSET(yellow_blue.highlights),
>> AV_OPT_TYPE_DOUBLE, {.dbl=0}, -100, 100, FLAGS },
>> + { NULL }
>> +};
>> +
>> +AVFILTER_DEFINE_CLASS(colorbalance);
>> +
>> +static int query_formats(AVFilterContext *ctx)
>> +{
>> + static const enum AVPixelFormat pix_fmts[] = {
>> + AV_PIX_FMT_RGB24, AV_PIX_FMT_BGR24,
>> + AV_PIX_FMT_RGBA, AV_PIX_FMT_BGRA,
>> + AV_PIX_FMT_ABGR, AV_PIX_FMT_ARGB,
>> + AV_PIX_FMT_0BGR, AV_PIX_FMT_0RGB,
>> + AV_PIX_FMT_RGB0, AV_PIX_FMT_BGR0,
>> + AV_PIX_FMT_NONE
>> + };
>> +
>> + ff_set_common_formats(ctx, ff_make_format_list(pix_fmts));
>> + return 0;
>> +}
>> +
>> +static int config_output(AVFilterLink *outlink)
>> +{
>> + AVFilterContext *ctx = outlink->src;
>> + ColorBalanceContext *cb = ctx->priv;
>> + const AVPixFmtDescriptor *desc =
>> av_pix_fmt_desc_get(outlink->format);
>> + double *add[3], *sub[3];
>> + double *coeff[3][3];
>> + double *buffer;
>> + int i, r, g, b;
>> +
>> + buffer = av_malloc(256 * 3 * 2 * sizeof(double));
>> + if (!buffer)
>> + return AVERROR(ENOMEM);
>> +
>> + for (i = 0; i < 3; i++) {
>> + add[i] = buffer + 256 * i;
>> + sub[i] = buffer + 256 * (3 + i);
>> + }
>> +
>
>> + for (i = 0; i < 256; i++) {
>> + double low = (1.075 - 1 / (i / 16.0 + 1));
>> + double mid = 2.0 / 3.0 * (1 - ((i - 127.0) / 127.0) * ((i -
>> 127.0) / 127.0));
>> +
>> + add[0][i] = low;
>> + add[1][i] = mid;
>> + add[2][255 - i] = low;
>> + sub[0][255 - i] = low;
>> + sub[1][i] = mid;
>> + sub[2][i] = low;
>> + }
>> +
>
> short explanation or link to paper is welcome
>
>> + coeff[0][0] = cb->cyan_red.shadows > 0 ? add[0] : sub[0];
>> + coeff[1][0] = cb->magenta_green.shadows > 0 ? add[0] : sub[0];
>> + coeff[2][0] = cb->yellow_blue.shadows > 0 ? add[0] : sub[0];
>
>> + coeff[0][1] = cb->cyan_red.midtones > 0 ? add[1] : sub[1];
>> + coeff[1][1] = cb->magenta_green.midtones > 0 ? add[1] : sub[1];
>> + coeff[2][1] = cb->yellow_blue.midtones > 0 ? add[1] : sub[1];
>
>> + coeff[0][2] = cb->cyan_red.highlights > 0 ? add[2] : sub[2];
>> + coeff[1][2] = cb->magenta_green.highlights > 0 ? add[2] : sub[2];
>> + coeff[2][2] = cb->yellow_blue.highlights > 0 ? add[2] : sub[2];
>
> nit: vertical align
>
>> +
>> + for (i = 0; i < 256; i++) {
>> + r = g = b = i;
>> +
>
>> + r = av_clip_uint8(r + cb->cyan_red.shadows * coeff[0][0][r]);
>> + r = av_clip_uint8(r + cb->cyan_red.midtones * coeff[0][1][r]);
>> + r = av_clip_uint8(r + cb->cyan_red.highlights * coeff[0][2][r]);
>> +
>> + g = av_clip_uint8(g + cb->magenta_green.shadows *
>> coeff[1][0][g]);
>> + g = av_clip_uint8(g + cb->magenta_green.midtones *
>> coeff[1][1][g]);
>> + g = av_clip_uint8(g + cb->magenta_green.highlights *
>> coeff[1][2][g]);
>> +
>> + b = av_clip_uint8(b + cb->yellow_blue.shadows * coeff[2][0][b]);
>> + b = av_clip_uint8(b + cb->yellow_blue.midtones *
>> coeff[2][1][b]);
>> + b = av_clip_uint8(b + cb->yellow_blue.highlights *
>> coeff[2][2][b]);
>
> nit: vertical align
>
>> +
>> + cb->lookup[0][i] = r;
>> + cb->lookup[1][i] = g;
>> + cb->lookup[2][i] = b;
>> + }
>> +
>> + av_free(buffer);
>> +
>> + ff_fill_rgba_map(cb->rgba_map, outlink->format);
>
>> + cb->nb_components = av_get_padded_bits_per_pixel(desc) >> 3;
>
> pixdesc->nb_components, the formula is wrong (even if it produces the
> pixdesc->expected result)
Not for RGB0 and others ....
>
> [...]
> --
> FFmpeg = Forgiving and Formidable Multimedia Perennial Elastic Gladiator
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