Hi,
This patch introduces Grey-Edge algorithm as part of the Color
Constancy Filter project in GSOC.
V2 changes:
- added documentation ini filters.texi
- remove currently not useful code (saving to file)
Best regards,
Mina Sami
>From deb1cad1bb007b7372dd128581033c5c63b63ee6 Mon Sep 17 00:00:00 2001
From: Mina <minasa...@hotmail.com>
Date: Sun, 15 Jul 2018 04:16:13 +0200
Subject: [PATCH] avfilter: added colorconstancy
Signed-off-by: Mina <minasa...@hotmail.com>
---
Changelog | 1 +
MAINTAINERS | 1 +
doc/filters.texi | 38 ++
libavfilter/Makefile | 1 +
libavfilter/allfilters.c | 1 +
libavfilter/vf_colorconstancy.c | 756 ++++++++++++++++++++++++++++++++
6 files changed, 798 insertions(+)
create mode 100644 libavfilter/vf_colorconstancy.c
diff --git a/Changelog b/Changelog
index e43a159b0d..dfdb2f38af 100644
--- a/Changelog
+++ b/Changelog
@@ -14,6 +14,7 @@ version <next>:
- libtensorflow backend for DNN based filters like srcnn
- vc1 decoder is now bit-exact
- ATRAC9 decoder
+- colorconstancy filter
version 4.0:
diff --git a/MAINTAINERS b/MAINTAINERS
index 78f450dda6..234b655cef 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -332,6 +332,7 @@ Filters:
vf_bwdif Thomas Mundt (CC <thomas.mu...@hr.de>)
vf_chromakey.c Timo Rothenpieler
vf_colorchannelmixer.c Paul B Mahol
+ vf_colorconstancy.c Mina Sami (CC <minas.go...@gmail.com>)
vf_colorbalance.c Paul B Mahol
vf_colorkey.c Timo Rothenpieler
vf_colorlevels.c Paul B Mahol
diff --git a/doc/filters.texi b/doc/filters.texi
index 49895ff947..a787068939 100644
--- a/doc/filters.texi
+++ b/doc/filters.texi
@@ -9940,6 +9940,44 @@ gradfun=radius=8
@end itemize
+@section greyedge
+
+A variation color constancy that estimates scene illumination via grey edge algorithm
+and corrects the scene colors accordingly.
+
+The filter accepts the following options:
+
+@table @option
+@item difford
+The order of diffrentation to be applied on the scene. Must be chosen in the range
+[0,2] and default value is 1.
+
+@item minknorm
+The Minkowski parameter to be used for calculating the Minkowski distance. Must
+be chosen in the range [0,65535] and default value is 1. Set to 0 for getting
+max value instead of calculating Minkowski distance.
+
+@item sigma
+The standard deviation of Gaussian blur to be applied on the scene. Must be
+chosen in the range [0,1024.0] and default value = 1. Sigma can't be set to 0
+if @var{difford} is greater than 1.
+
+@subsection Examples
+
+@item
+Grey Edge:
+@example
+greyedge=difford=1:minknorm=5:sigma=2
+@end example
+@end itemize
+
+@item
+Max Edge:
+@example
+greyedge=difford=1:minknorm=0:sigma=2
+@end example
+@end itemize
+
@anchor{haldclut}
@section haldclut
diff --git a/libavfilter/Makefile b/libavfilter/Makefile
index 7735c26529..ebe43e1391 100644
--- a/libavfilter/Makefile
+++ b/libavfilter/Makefile
@@ -228,6 +228,7 @@ OBJS-$(CONFIG_FSPP_FILTER) += vf_fspp.o
OBJS-$(CONFIG_GBLUR_FILTER) += vf_gblur.o
OBJS-$(CONFIG_GEQ_FILTER) += vf_geq.o
OBJS-$(CONFIG_GRADFUN_FILTER) += vf_gradfun.o
+OBJS-$(CONFIG_GREYEDGE_FILTER) += vf_colorconstancy.o
OBJS-$(CONFIG_HALDCLUT_FILTER) += vf_lut3d.o framesync.o
OBJS-$(CONFIG_HFLIP_FILTER) += vf_hflip.o
OBJS-$(CONFIG_HISTEQ_FILTER) += vf_histeq.o
diff --git a/libavfilter/allfilters.c b/libavfilter/allfilters.c
index 0ded83ede2..9c99b03a81 100644
--- a/libavfilter/allfilters.c
+++ b/libavfilter/allfilters.c
@@ -217,6 +217,7 @@ extern AVFilter ff_vf_fspp;
extern AVFilter ff_vf_gblur;
extern AVFilter ff_vf_geq;
extern AVFilter ff_vf_gradfun;
+extern AVFilter ff_vf_greyedge;
extern AVFilter ff_vf_haldclut;
extern AVFilter ff_vf_hflip;
extern AVFilter ff_vf_histeq;
diff --git a/libavfilter/vf_colorconstancy.c b/libavfilter/vf_colorconstancy.c
new file mode 100644
index 0000000000..281a4cb43d
--- /dev/null
+++ b/libavfilter/vf_colorconstancy.c
@@ -0,0 +1,756 @@
+/*
+ * Copyright (c) 2018 Mina Sami
+ *
+ * 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
+ */
+
+/**
+ * @file
+ * Color Constancy filter
+ *
+ * @see http://colorconstancy.com/
+ *
+ * @cite
+ * J. van de Weijer, Th. Gevers, A. Gijsenij "Edge-Based Color Constancy".
+ */
+
+#include "libavutil/avassert.h"
+#include "libavutil/bprint.h"
+#include "libavutil/imgutils.h"
+#include "libavutil/opt.h"
+#include "libavutil/pixdesc.h"
+
+#include "avfilter.h"
+#include "formats.h"
+#include "internal.h"
+#include "video.h"
+
+#include <math.h>
+
+#define GREY_EDGE "greyedge"
+
+#define NUM_PLANES 3
+#define MAX_DIFF_ORD 2
+#define MAX_META_DATA 4
+#define MAX_DATA 4
+
+#define INDEX_TEMP 0
+#define INDEX_DX 1
+#define INDEX_DY 2
+#define INDEX_DXY 3
+#define INDEX_NORM INDEX_DX
+#define INDEX_SRC 0
+#define INDEX_DST 1
+#define INDEX_ORD 2
+#define INDEX_DIR 3
+#define DIR_X 0
+#define DIR_Y 1
+
+/**
+ * Used for passing data between threads.
+ */
+typedef struct ThreadData {
+ AVFrame *in, *out;
+ int meta_data[MAX_META_DATA];
+ double *data[MAX_DATA][NUM_PLANES];
+} ThreadData;
+
+/**
+ * Common struct for all algorithms contexts.
+ */
+typedef struct ColorConstancyContext {
+ const AVClass *class;
+
+ int difford;
+ int minknorm; /**< @minknorm = 0 : getMax instead */
+ double sigma;
+
+ int nb_threads;
+ int planeheight[4];
+ int planewidth[4];
+
+ int filtersize;
+ double *gauss[MAX_DIFF_ORD+1];
+
+ double white[NUM_PLANES];
+} ColorConstancyContext;
+
+#define OFFSET(x) offsetof(ColorConstancyContext, x)
+#define FLAGS AV_OPT_FLAG_FILTERING_PARAM|AV_OPT_FLAG_VIDEO_PARAM
+
+#define GINDX(s, i) ( (i) - ((s) >> 2) )
+
+/**
+ * Sets gauss filters used for calculating gauss derivatives. Filter size
+ * depends on sigma which is a user option hence we calculate these
+ * filters each time. Also each higher order depends on lower ones. Sigma
+ * can be zero only at difford = 0, then we only convert data to double
+ * instead.
+ *
+ * @param ctx the filter context.
+ *
+ * @return 0 in case of success, a negative value corresponding to an
+ * AVERROR code in case of failure.
+ */
+static int set_gauss(AVFilterContext *ctx)
+{
+ ColorConstancyContext *s = ctx->priv;
+ int filtersize = s->filtersize;
+ int difford = s->difford;
+ double sigma = s->sigma;
+ double sum1, sum2;
+ int i;
+
+ for (i = 0; i <= difford; ++i) {
+ s->gauss[i] = av_mallocz_array(filtersize, sizeof(*s->gauss[i]));
+ if (!s->gauss[i]) {
+ for (; i >= 0; --i) {
+ av_freep(&s->gauss[i]);
+ }
+ av_log(ctx, AV_LOG_ERROR, "Out of memory while allocating gauss buffers.\n");
+ return AVERROR(ENOMEM);
+ }
+ }
+
+ // Order 0
+ av_log(ctx, AV_LOG_TRACE, "Setting 0-d gauss with filtersize = %d.\n", filtersize);
+ sum1 = 0.0;
+ if (!sigma) {
+ s->gauss[0][0] = 1; // Copying data to double instead of convolution
+ } else {
+ for (i = 0; i < filtersize; ++i) {
+ s->gauss[0][i] = exp(- pow(GINDX(filtersize, i), 2.) / (2 * sigma * sigma)) / ( sqrt(2 * M_PI) * sigma );
+ sum1 += s->gauss[0][i];
+ }
+ for (i = 0; i < filtersize; ++i) {
+ s->gauss[0][i] /= sum1;
+ }
+ }
+ // Order 1
+ if (difford > 0) {
+ av_log(ctx, AV_LOG_TRACE, "Setting 1-d gauss with filtersize = %d.\n", filtersize);
+ sum1 = 0.0;
+ for (i = 0; i < filtersize; ++i) {
+ s->gauss[1][i] = - (GINDX(filtersize, i) / pow(sigma, 2)) * s->gauss[0][i];
+ sum1 += s->gauss[1][i] *GINDX(filtersize, i);
+ }
+
+ for (i = 0; i < filtersize; ++i) {
+ s->gauss[1][i] /= sum1;
+ }
+
+ // Order 2
+ if (difford > 1) {
+ av_log(ctx, AV_LOG_TRACE, "Setting 2-d gauss with filtersize = %d.\n", filtersize);
+ sum1 = 0.0;
+ for (i = 0; i < filtersize; ++i) {
+ s->gauss[2][i] = ( pow(GINDX(filtersize, i), 2) / pow(sigma, 4) - 1/pow(sigma, 2) )
+ * s->gauss[0][i];
+ sum1 += s->gauss[2][i];
+ }
+
+ sum2 = 0.0;
+ for (i = 0; i < filtersize; ++i) {
+ s->gauss[2][i] -= sum1 / (filtersize);
+ sum2 += (0.5 * GINDX(filtersize, i) * GINDX(filtersize, i) * s->gauss[2][i]);
+ }
+ for (i = 0; i < filtersize ; ++i) {
+ s->gauss[2][i] /= sum2;
+ }
+ }
+ }
+ return 0;
+}
+
+/**
+ * Frees up buffers used by grey edge for storing derivatives final
+ * and intermidiate results. Number of buffers and number of planes
+ * for last buffer are given so it can be safely called at allocation
+ * failure instances.
+ *
+ * @param td holds the buffers.
+ * @param nb_buff number of buffers to be freed.
+ * @param nb_planes number of planes for last buffer to be freed.
+ */
+static void cleanup_derivative_buffers(ThreadData *td, int nb_buff, int nb_planes)
+{
+ int b, p;
+
+ for (b = 0; b < nb_buff; ++b) {
+ for (p = 0; p < NUM_PLANES; ++p) {
+ av_freep(&td->data[b][p]);
+ }
+ }
+ // Final buffer may not be fully allocated at fail cases
+ for (p = 0; p < nb_planes; ++p) {
+ av_freep(&td->data[b][p]);
+ }
+}
+
+/**
+ * Allocates buffers used by grey edge for storing derivatives final
+ * and intermidiate results.
+ *
+ * @param ctx the filter context.
+ * @param td holds the buffers.
+ *
+ * @return 0 in case of success, a negative value corresponding to an
+ * AVERROR code in case of failure.
+ */
+static int setup_derivative_buffers(AVFilterContext* ctx, ThreadData *td)
+{
+ ColorConstancyContext *s = ctx->priv;
+ int nb_buff = s->difford + 1;
+ int b, p;
+
+ av_log(ctx, AV_LOG_TRACE, "Allocating %d buffer(s) for grey edge.\n", nb_buff);
+ for (b = 0; b <= nb_buff; ++b) { // We need difford + 1 buffers
+ for (p = 0; p < NUM_PLANES; ++p) {
+ td->data[b][p] = av_mallocz_array(s->planeheight[p] * s->planewidth[p], sizeof(*td->data[b][p]));
+ if (!td->data[b][p]) {
+ cleanup_derivative_buffers(td, b + 1, p);
+ av_log(ctx, AV_LOG_ERROR, "Out of memory while allocating derivatives buffers.\n");
+ return AVERROR(ENOMEM);
+ }
+ }
+ }
+ return 0;
+}
+
+#define CLAMP(x, mx) av_clip((x), 0, (mx-1))
+#define INDX2D(r, c, w) ( (r) * (w) + (c) )
+#define GAUSS(s, sr, sc, sls, sh, sw, g) ( (s)[ INDX2D(CLAMP((sr), (sh)), CLAMP((sc), (sw)), (sls)) ] * (g) )
+
+/**
+ * Slice calculation of gaussian derivatives. Applies 1-D gaussian derivative filter
+ * either horizontally or vertically according to meta data given in thread data.
+ * When convoluting horizontally source is always the in frame withing thread data
+ * while when convoluting vertically source is a buffer.
+ *
+ * @param ctx the filter context.
+ * @param arg data to be passed between threads.
+ * @param jobnr current job nubmer.
+ * @param nb_jobs total number of jobs.
+ *
+ * @return 0.
+ */
+static int slice_get_derivative(AVFilterContext* ctx, void* arg, int jobnr, int nb_jobs)
+{
+ ColorConstancyContext *s = ctx->priv;
+ ThreadData *td = arg;
+ AVFrame *in = td->in;
+ const int ord = td->meta_data[INDEX_ORD];
+ const int dir = td->meta_data[INDEX_DIR];
+ const int src_index = td->meta_data[INDEX_SRC];
+ const int dst_index = td->meta_data[INDEX_DST];
+ const int filtersize = s->filtersize;
+ const double *gauss = s->gauss[ord];
+ int plane;
+
+ for (plane = 0; plane < NUM_PLANES; ++plane) {
+ const int height = s->planeheight[plane];
+ const int width = s->planewidth[plane];
+ const int in_linesize = in->linesize[plane];
+ double *dst = td->data[dst_index][plane];
+ int slice_start, slice_end;
+ int r, c, g;
+
+ if (dir == DIR_X) {
+ /** Applying gauss horizontally along each row */
+ const uint8_t *src = in->data[plane];
+ slice_start = (height * jobnr ) / nb_jobs;
+ slice_end = (height * (jobnr + 1)) / nb_jobs;
+
+ for (r = slice_start; r < slice_end; ++r) {
+ for (c = 0; c < width; ++c) {
+ dst[INDX2D(r, c, width)] = 0;
+ for (g = 0; g < filtersize; ++g) {
+ dst[INDX2D(r, c, width)] += GAUSS(src, r, c + GINDX(filtersize, g),
+ in_linesize, height, width, gauss[GINDX(filtersize, g)]);
+ }
+ }
+ }
+ } else {
+ /** Applying gauss vertically along each column */
+ const double *src = td->data[src_index][plane];
+ slice_start = (width * jobnr ) / nb_jobs;
+ slice_end = (width * (jobnr + 1)) / nb_jobs;
+
+ for (c = slice_start; c < slice_end; ++c) {
+ for (r = 0; r < height; ++r) {
+ dst[INDX2D(r, c, width)] = 0;
+ for (g = 0; g < filtersize; ++g) {
+ dst[INDX2D(r, c, width)] += GAUSS(src, r + GINDX(filtersize, g), c,
+ width, height, width, gauss[GINDX(filtersize, g)]);
+ }
+ }
+ }
+ }
+
+ }
+ return 0;
+}
+
+/**
+ * Slice Frobius normalization of gaussian derivatives. Only called for difford values of
+ * 1 or 2.
+ *
+ * @param ctx the filter context.
+ * @param arg data to be passed between threads.
+ * @param jobnr current job nubmer.
+ * @param nb_jobs total number of jobs.
+ *
+ * @return 0.
+ */
+static int slice_normalize(AVFilterContext* ctx, void* arg, int jobnr, int nb_jobs)
+{
+ ColorConstancyContext *s = ctx->priv;
+ ThreadData *td = arg;
+ const int difford = s->difford;
+ int plane;
+
+ for (plane = 0; plane < NUM_PLANES; ++plane) {
+ const int height = s->planeheight[plane];
+ const int width = s->planewidth[plane];
+ const int64_t numpixels = width * (int64_t)height;
+ const int slice_start = (numpixels * jobnr ) / nb_jobs;
+ const int slice_end = (numpixels * (jobnr+1)) / nb_jobs;
+ const double *dx = td->data[INDEX_DX][plane];
+ const double *dy = td->data[INDEX_DY][plane];
+ double *norm = td->data[INDEX_NORM][plane];
+ int i;
+
+ if (difford == 1) {
+ for (i = slice_start; i < slice_end; ++i) {
+ norm[i] = sqrt( pow(dx[i], 2) + pow(dy[i], 2));
+ }
+ } else {
+ const double *dxy = td->data[INDEX_DXY][plane];
+ for (i = slice_start; i < slice_end; ++i) {
+ norm[i] = sqrt( pow(dx[i], 2) + 4 * pow(dxy[i], 2) + pow(dy[i], 2) );
+ }
+ }
+ }
+
+ return 0;
+}
+
+/**
+ * Utility function for setting up differentiation data/metadata.
+ *
+ * @param ctx the filter context.
+ * @param td to be used for passing data between threads.
+ * @param ord ord of differentiation.
+ * @param dir direction of differentiation.
+ * @param src index of source used for differentiation.
+ * @param dst index destination used for saving differentiation result.
+ * @param dim maximum dimension in current direction.
+ * @param nb_threads number of threads to use.
+ */
+static void av_always_inline
+get_deriv(AVFilterContext *ctx, ThreadData *td, int ord, int dir,
+ int src, int dst, int dim, int nb_threads) {
+ td->meta_data[INDEX_ORD] = ord;
+ td->meta_data[INDEX_DIR] = dir;
+ td->meta_data[INDEX_SRC] = src;
+ td->meta_data[INDEX_DST] = dst;
+ ctx->internal->execute(ctx, slice_get_derivative, td, NULL, FFMIN(dim, nb_threads));
+}
+
+/**
+ * Main control function for calculating gaussian derivatives.
+ *
+ * @param ctx the filter context.
+ * @param td holds the buffers used for storing results.
+ *
+ * @return 0 in case of success, a negative value corresponding to an
+ * AVERROR code in case of failure.
+ */
+static int get_derivative(AVFilterContext *ctx, ThreadData *td)
+{
+ ColorConstancyContext *s = ctx->priv;
+ int nb_threads = s->nb_threads;
+ int height = s->planeheight[1];
+ int width = s->planewidth[1];
+
+ switch(s->difford) {
+ case 0:
+ if (!s->sigma) { // Only copy once
+ get_deriv(ctx, td, 0, DIR_X, 0 , INDEX_NORM, height, nb_threads);
+ } else {
+ get_deriv(ctx, td, 0, DIR_X, 0, INDEX_TEMP, height, nb_threads);
+ get_deriv(ctx, td, 0, DIR_Y, INDEX_TEMP, INDEX_NORM, width , nb_threads);
+ // save to INDEX_NORM because this will not be normalied and
+ // end gry edge filter expects result to be found in INDEX_NORM
+ }
+ return 0;
+
+ case 1:
+ get_deriv(ctx, td, 1, DIR_X, 0, INDEX_TEMP, height, nb_threads);
+ get_deriv(ctx, td, 0, DIR_Y, INDEX_TEMP, INDEX_DX, width , nb_threads);
+
+ get_deriv(ctx, td, 0, DIR_X, 0, INDEX_TEMP, height, nb_threads);
+ get_deriv(ctx, td, 1, DIR_Y, INDEX_TEMP, INDEX_DY, width , nb_threads);
+ return 0;
+
+ case 2:
+ get_deriv(ctx, td, 2, DIR_X, 0, INDEX_TEMP, height, nb_threads);
+ get_deriv(ctx, td, 0, DIR_Y, INDEX_TEMP, INDEX_DX, width , nb_threads);
+
+ get_deriv(ctx, td, 0, DIR_X, 0, INDEX_TEMP, height, nb_threads);
+ get_deriv(ctx, td, 2, DIR_Y, INDEX_TEMP, INDEX_DY, width , nb_threads);
+
+ get_deriv(ctx, td, 1, DIR_X, 0, INDEX_TEMP, height, nb_threads);
+ get_deriv(ctx, td, 1, DIR_Y, INDEX_TEMP, INDEX_DXY, width , nb_threads);
+ return 0;
+
+ default:
+ av_log(ctx, AV_LOG_ERROR, "Unsupported difford value: %d.\n", s->difford);
+ return AVERROR(EINVAL);
+ }
+
+}
+
+/**
+ * Slice function for grey edge algorithm that does partial summing/maximizing
+ * of gaussian derivatives.
+ *
+ * @param ctx the filter context.
+ * @param arg data to be passed between threads.
+ * @param jobnr current job nubmer.
+ * @param nb_jobs total number of jobs.
+ *
+ * @return 0.
+ */
+static int filter_slice_grey_edge(AVFilterContext* ctx, void* arg, int jobnr, int nb_jobs)
+{
+ ColorConstancyContext *s = ctx->priv;
+ ThreadData *td = arg;
+ AVFrame *in = td->in;
+ int minknorm = s->minknorm;
+ const uint8_t thresh = 255;
+ int plane;
+
+ for (plane = 0; plane < NUM_PLANES; ++plane) {
+ const int height = s->planeheight[plane];
+ const int width = s->planewidth[plane];
+ const int in_linesize = in->linesize[plane];
+ const int slice_start = (height * jobnr) / nb_jobs;
+ const int slice_end = (height * (jobnr+1)) / nb_jobs;
+ const uint8_t *img_data = in->data[plane];
+ const double *src = td->data[INDEX_NORM][plane];
+ double *dst = td->data[INDEX_DST][plane];
+ int r, c;
+
+ dst[jobnr] = 0;
+ if (!minknorm) {
+ for (r = slice_start; r < slice_end; ++r) {
+ for (c = 0; c < width; ++c) {
+ dst[jobnr] = FFMAX( dst[jobnr], fabs(src[INDX2D(r, c, width)])
+ * (img_data[INDX2D(r, c, in_linesize)] < thresh) );
+ }
+ }
+ } else {
+ for (r = slice_start; r < slice_end; ++r) {
+ for (c = 0; c < width; ++c) {
+ dst[jobnr] += ( pow( fabs(src[INDX2D(r, c, width)] / 255.), minknorm)
+ * (img_data[INDX2D(r, c, in_linesize)] < thresh) );
+ }
+ }
+ }
+ }
+ return 0;
+}
+
+/**
+ * Main control function for grey edge algorithm.
+ *
+ * @param ctx the filter context.
+ * @param in frame to perfrom grey edge on.
+ *
+ * @return 0 in case of success, a negative value corresponding to an
+ * AVERROR code in case of failure.
+ */
+static int filter_grey_edge(AVFilterContext *ctx, AVFrame *in)
+{
+ ColorConstancyContext *s = ctx->priv;
+ ThreadData td;
+ int minknorm = s->minknorm;
+ int difford = s->difford;
+ double *white = s->white;
+ int nb_jobs = FFMIN3(s->planeheight[1], s->planewidth[1], s->nb_threads);
+ int plane, job, ret;
+
+ td.in = in;
+ ret = setup_derivative_buffers(ctx, &td);
+ if (ret) {
+ return ret;
+ }
+ get_derivative(ctx, &td);
+ if (difford > 0) {
+ ctx->internal->execute(ctx, slice_normalize, &td, NULL, nb_jobs);
+ }
+
+ ctx->internal->execute(ctx, filter_slice_grey_edge, &td, NULL, nb_jobs);
+ if (!minknorm) {
+ for (plane = 0; plane < NUM_PLANES; ++plane) {
+ white[plane] = 0; // All values are absolute
+ for (job = 0; job < nb_jobs; ++job) {
+ white[plane] = FFMAX(white[plane] , td.data[INDEX_DST][plane][job]);
+ }
+ }
+ } else {
+ for (plane = 0; plane < NUM_PLANES; ++plane) {
+ white[plane] = 0;
+ for (job = 0; job < nb_jobs; ++job) {
+ white[plane] += td.data[INDEX_DST][plane][job];
+ }
+ white[plane] = pow(white[plane], 1./minknorm);
+ }
+ }
+
+ cleanup_derivative_buffers(&td, difford + 1, NUM_PLANES);
+ return 0;
+}
+
+/**
+ * Normalizes estimated illumination since only illumination vector
+ * direction is required for color constancy.
+ *
+ * @param light the estimated illumination to be normalized in place
+ */
+static void normalize_light(double *light)
+{
+ double abs_val = pow( pow(light[0], 2.0) + pow(light[1], 2.0) + pow(light[2], 2.0), 0.5);
+ int plane;
+
+ // TODO: check if setting to 1.0 when estimated = 0.0 is the best thing to do
+
+ if (!abs_val) {
+ for (plane = 0; plane < NUM_PLANES; ++plane) {
+ light[plane] = 1.0;
+ }
+ } else {
+ for (plane = 0; plane < NUM_PLANES; ++plane) {
+ light[plane] = (light[plane] / abs_val);
+ if (!light[plane]) { // to avoid division by zero when correcting
+ light[plane] = 1.0;
+ }
+ }
+ }
+}
+
+/**
+ * Redirects to corresponding algorithm estimation function and performs normalization
+ * after estimation.
+ *
+ * @param ctx the filter context.
+ * @param in frame to perfrom estimation on.
+ *
+ * @return 0 in case of success, a negative value corresponding to an
+ * AVERROR code in case of failure.
+ */
+static int illumination_estimation(AVFilterContext *ctx, AVFrame *in)
+{
+ ColorConstancyContext *s = ctx->priv;
+ int ret;
+
+ ret = filter_grey_edge(ctx, in);
+
+ av_log(ctx, AV_LOG_DEBUG, "Estimated illumination= %f %f %f\n",
+ s->white[0], s->white[1], s->white[2]);
+ normalize_light(s->white);
+ av_log(ctx, AV_LOG_DEBUG, "Estimated illumination after normalization= %f %f %f\n",
+ s->white[0], s->white[1], s->white[2]);
+
+ return ret;
+}
+
+/**
+ * Performs simple correction via diagonal transformation model.
+ *
+ * @param ctx the filter context.
+ * @param arg data to be passed between threads.
+ * @param jobnr current job nubmer.
+ * @param nb_jobs total number of jobs.
+ *
+ * @return 0.
+ */
+static int diagonal_transformation(AVFilterContext *ctx, void *arg, int jobnr, int nb_jobs)
+{
+ ColorConstancyContext *s = ctx->priv;
+ ThreadData *td = arg;
+ AVFrame *in = td->in;
+ AVFrame *out = td->out;
+ double sqrt3 = pow(3.0, 0.5);
+ int plane;
+
+ for (plane = 0; plane < NUM_PLANES; ++plane) {
+ const int height = s->planeheight[plane];
+ const int width = s->planewidth[plane];
+ const int64_t numpixels = width * (int64_t)height;
+ const int slice_start = (numpixels * jobnr) / nb_jobs;
+ const int slice_end = (numpixels * (jobnr+1)) / nb_jobs;
+ const uint8_t *src = in->data[plane];
+ uint8_t *dst = out->data[plane];
+ double temp;
+ unsigned i;
+
+ for (i = slice_start; i < slice_end; ++i) {
+ temp = src[i] / (s->white[plane] * sqrt3);
+ dst[i] = av_clip_uint8((int)(temp + 0.5));
+ }
+ }
+ return 0;
+}
+
+/**
+ * Main control function for correcting scene illumination based on
+ * estimated illumination.
+ *
+ * @param ctx the filter context.
+ * @param in holds frame to correct
+ * @param out holds corrected frame
+ */
+static void chromatic_adaptation(AVFilterContext *ctx, AVFrame *in, AVFrame *out)
+{
+ ColorConstancyContext *s = ctx->priv;
+ ThreadData td;
+ int nb_jobs = FFMIN3(s->planeheight[1], s->planewidth[1], s->nb_threads);
+
+ td.in = in;
+ td.out = out;
+ ctx->internal->execute(ctx, diagonal_transformation, &td, NULL, nb_jobs);
+}
+
+static int query_formats(AVFilterContext *ctx)
+{
+ static const enum AVPixelFormat pix_fmts[] = {
+ // TODO: support more formats
+ // FIXME: error when saving to .jpg
+ AV_PIX_FMT_GBRP,
+ AV_PIX_FMT_NONE
+ };
+
+ return ff_set_common_formats(ctx, ff_make_format_list(pix_fmts));
+}
+
+static int config_props(AVFilterLink *inlink)
+{
+ AVFilterContext *ctx = inlink->dst;
+ ColorConstancyContext *s = ctx->priv;
+ const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(inlink->format);
+ const double break_off_sigma = 3.0;
+ double sigma = s->sigma;
+ int ret;
+
+ av_assert0(sigma || !s->difford);
+
+ s->filtersize = 2 * floor(break_off_sigma * s->sigma + 0.5) + 1;
+ if (ret=set_gauss(ctx)) {
+ return ret;
+ }
+
+ s->nb_threads = ff_filter_get_nb_threads(ctx);
+ s->planewidth[1] = s->planewidth[2] = AV_CEIL_RSHIFT(inlink->w, desc->log2_chroma_w);
+ s->planewidth[0] = s->planewidth[3] = inlink->w;
+ s->planeheight[1] = s->planeheight[2] = AV_CEIL_RSHIFT(inlink->h, desc->log2_chroma_h);
+ s->planeheight[0] = s->planeheight[3] = inlink->h;
+
+ return 0;
+}
+
+static int filter_frame(AVFilterLink *inlink, AVFrame *in)
+{
+ AVFilterContext *ctx = inlink->dst;
+ AVFilterLink *outlink = ctx->outputs[0];
+ AVFrame *out;
+ int ret;
+
+ ret = illumination_estimation(ctx, in);
+ if (ret) {
+ return ret;
+ }
+
+ if (av_frame_is_writable(in)) {
+ out = in;
+ } else {
+ out = ff_get_video_buffer(outlink, outlink->w, outlink->h);
+ if (!out) {
+ av_log(ctx, AV_LOG_ERROR, "Out of memory while allocating output video buffer.\n");
+ return AVERROR(ENOMEM);
+ }
+ av_frame_copy_props(out, in);
+ }
+ chromatic_adaptation(ctx, in, out);
+
+ return ff_filter_frame(outlink, out);
+}
+
+static av_cold void uninit(AVFilterContext *ctx)
+{
+ ColorConstancyContext *s = ctx->priv;
+ int difford = s->difford;
+ int i;
+
+ for (i = 0; i <= difford; ++i) {
+ av_freep(&s->gauss[i]);
+ }
+}
+
+static const AVFilterPad colorconstancy_inputs[] = {
+ {
+ .name = "default",
+ .type = AVMEDIA_TYPE_VIDEO,
+ .config_props = config_props,
+ .filter_frame = filter_frame,
+ },
+ { NULL }
+};
+
+static const AVFilterPad colorconstancy_outputs[] = {
+ {
+ .name = "default",
+ .type = AVMEDIA_TYPE_VIDEO,
+ },
+ { NULL }
+};
+
+#if CONFIG_GREYEDGE_FILTER
+
+static const AVOption greyedge_options[] = {
+ { "difford", "set differentiation order", OFFSET(difford), AV_OPT_TYPE_INT, {.i64=1}, 0, 2, FLAGS },
+ { "minknorm", "set Minkowski norm", OFFSET(minknorm), AV_OPT_TYPE_INT, {.i64=1}, 0, 65535, FLAGS },
+ { "sigma", "set sigma", OFFSET(sigma), AV_OPT_TYPE_DOUBLE, {.dbl=1}, 0.0, 1024.0, FLAGS },
+ { NULL }
+};
+
+AVFILTER_DEFINE_CLASS(greyedge);
+
+AVFilter ff_vf_greyedge = {
+ .name = GREY_EDGE,
+ .description = NULL_IF_CONFIG_SMALL("Estimates scene illumination by grey edge assumption."),
+ .priv_size = sizeof(ColorConstancyContext),
+ .priv_class = &greyedge_class,
+ .query_formats = query_formats,
+ .uninit = uninit,
+ .inputs = colorconstancy_inputs,
+ .outputs = colorconstancy_outputs,
+ .flags = AVFILTER_FLAG_SUPPORT_TIMELINE_GENERIC | AVFILTER_FLAG_SLICE_THREADS,
+};
+
+#endif /* CONFIG_GREY_EDGE_FILTER */
--
2.17.0
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