[FFmpeg-devel] [PATCH] GSoC: Support fast guided filter.
mypopy at gmail.com
mypopy at gmail.com
Tue May 11 08:08:46 EEST 2021
On Mon, May 10, 2021 at 9:42 PM Xuewei Meng <928826483 at qq.com> wrote:
>
> From: Xuewei Meng <xwmeng96 at gmail.com>
>
> Two modes are supported in guided filter, basic mode and fast mode.
> Basic mode is the initial pushed guided filter without optimization.
> Fast mode is implemented based on the basic one by sub-sampling method.
> The sub-sampling ratio which can be defined by users controls the
> algorithm complexity. The larger the sub-sampling ratio, the lower
> the algorithm complexity.
>
> Signed-off-by: Xuewei Meng <xwmeng96 at gmail.com>
> ---
> doc/filters.texi | 20 +++++++---
> libavfilter/vf_guided.c | 104 ++++++++++++++++++++++++++++++++----------------
> 2 files changed, 85 insertions(+), 39 deletions(-)
>
> diff --git a/doc/filters.texi b/doc/filters.texi
> index 03ca9ae..eb747cb 100644
> --- a/doc/filters.texi
> +++ b/doc/filters.texi
> @@ -12963,12 +12963,22 @@ Apply guided filter for edge-preserving smoothing, dehazing and so on.
> The filter accepts the following options:
> @table @option
> @item radius
> -Set the radius in pixels.
> +Set the box radius in pixels.
> Allowed range is 1 to 20. Default is 3.
>
> @item eps
> -Set regularization parameter.
> -Allowed range is 0 to 1. Default is 0.1.
> +Set regularization parameter (with square).
> +Allowed range is 0 to 1. Default is 0.01.
> +
> + at item mode
> +Set filter mode. Can be @code{basic} or @code{fast}.
> +Default is @code{basic}.
> +
> + at item sub
> +Set subsampling ratio.
> +Allowed range is 1 to 64.
> +Default is always 1 for @code{basic} value of @var{mode} option,
> +and 4 for @code{fast} value of @var{mode} option.
>
> @item planes
> Set planes to filter. Default is first only.
> @@ -12987,8 +12997,8 @@ ffmpeg -i in.png -i in.png -filter_complex guided out.png
>
> @item
> Dehazing, structure-transferring filtering, detail enhancement with guided filter.
> -For the generation of guidance image,
> -see @url{http://kaiminghe.com/publications/pami12guidedfilter.pdf}.
> +For the generation of guidance image, refer to paper "Guided Image Filtering".
> +See: @url{http://kaiminghe.com/publications/pami12guidedfilter.pdf}.
> @example
> ffmpeg -i in.png -i guidance.png -filter_complex guided out.png
> @end example
> diff --git a/libavfilter/vf_guided.c b/libavfilter/vf_guided.c
> index 86c0db5..230fb7b 100644
> --- a/libavfilter/vf_guided.c
> +++ b/libavfilter/vf_guided.c
> @@ -27,12 +27,20 @@
> #include "internal.h"
> #include "video.h"
>
> +enum FilterModes {
> + BASIC,
> + FAST,
> + NB_MODES,
> +};
> +
> typedef struct GuidedContext {
> const AVClass *class;
> FFFrameSync fs;
>
> int radius;
> float eps;
> + int mode;
> + int sub;
>
> int planes;
>
> @@ -51,9 +59,13 @@ typedef struct GuidedContext {
> #define FLAGS AV_OPT_FLAG_VIDEO_PARAM|AV_OPT_FLAG_FILTERING_PARAM|AV_OPT_FLAG_RUNTIME_PARAM
>
> static const AVOption guided_options[] = {
> - { "radius", "set the box radius", OFFSET(radius), AV_OPT_TYPE_INT, {.i64=3 }, 1, 20, FLAGS },
> - { "eps", "set the regularization parameter (with square)", OFFSET(eps), AV_OPT_TYPE_FLOAT, {.dbl=0.01 }, 0.0, 1, FLAGS },
> - { "planes", "set planes to filter", OFFSET(planes), AV_OPT_TYPE_INT, {.i64=1 }, 0, 0xF, FLAGS },
> + { "radius", "set the box radius", OFFSET(radius), AV_OPT_TYPE_INT, {.i64 = 3 }, 1, 20, FLAGS },
> + { "eps", "set the regularization parameter (with square)", OFFSET(eps), AV_OPT_TYPE_FLOAT, {.dbl = 0.01 }, 0.0, 1, FLAGS },
> + { "mode", "set filtering mode (0: basic mode; 1: fast mode)", OFFSET(mode), AV_OPT_TYPE_INT, {.i64 = BASIC}, 0, NB_MODES - 1, FLAGS, "mode" },
> + { "basic", "basic guided filter", 0, AV_OPT_TYPE_CONST, {.i64 = BASIC}, 0, 0, FLAGS, "mode" },
> + { "fast", "fast guided filter", 0, AV_OPT_TYPE_CONST, {.i64 = FAST }, 0, 0, FLAGS, "mode" },
> + { "sub", "subsampling ratio", OFFSET(sub), AV_OPT_TYPE_INT, {.i64 = 1 }, 1, 64, FLAGS },
> + { "planes", "set planes to filter", OFFSET(planes), AV_OPT_TYPE_INT, {.i64=1 }, 0, 0xF, FLAGS },
> { NULL }
> };
>
> @@ -147,6 +159,26 @@ static int config_input(AVFilterLink *inlink)
> return AVERROR(EINVAL);
> }
>
> + if (s->mode == BASIC) {
> + if (s->sub != 1) {
> + av_log(ctx, AV_LOG_WARNING, "Subsampling ratio is 1 in basic mode.\n");
> + s->sub = 1;
> + }
> + }
> + else if (s->mode == FAST) {
> + if (s->sub == 1) {
> + av_log(ctx, AV_LOG_WARNING, "Subsampling ratio is larger than 1 in fast mode.\n");
> + s->sub = 4;
> + }
> + if (s->radius >= s->sub)
> + s->radius = s->radius / s->sub;
> + else {
> + s->radius = 1;
> + }
> + }
> + else {
> + return AVERROR_BUG;
> + }
>
> s->depth = desc->comp[0].depth;
> s->width = ctx->inputs[0]->w;
> @@ -174,6 +206,10 @@ static int guided_##name(AVFilterContext *ctx, GuidedContext *s,
> const type *src = (const type *)ssrc; \
> const type *srcRef = (const type *)ssrcRef; \
> \
> + int sub = s->sub; \
> + int h = (height % sub) == 0 ? height / sub : height / sub + 1; \
> + int w = (width % sub) == 0 ? width / sub : width / sub + 1; \
> + \
> ThreadData t; \
> const int nb_threads = ff_filter_get_nb_threads(ctx); \
> float *I; \
> @@ -189,55 +225,55 @@ static int guided_##name(AVFilterContext *ctx, GuidedContext *s,
> float *meanA; \
> float *meanB; \
> \
> - I = av_calloc(width * height, sizeof(float)); \
> - II = av_calloc(width * height, sizeof(float)); \
> - P = av_calloc(width * height, sizeof(float)); \
> - IP = av_calloc(width * height, sizeof(float)); \
> - meanI = av_calloc(width * height, sizeof(float)); \
> - meanII = av_calloc(width * height, sizeof(float)); \
> - meanP = av_calloc(width * height, sizeof(float)); \
> - meanIP = av_calloc(width * height, sizeof(float)); \
> + I = av_calloc(w * h, sizeof(float)); \
> + II = av_calloc(w * h, sizeof(float)); \
> + P = av_calloc(w * h, sizeof(float)); \
> + IP = av_calloc(w * h, sizeof(float)); \
> + meanI = av_calloc(w * h, sizeof(float)); \
> + meanII = av_calloc(w * h, sizeof(float)); \
> + meanP = av_calloc(w * h, sizeof(float)); \
> + meanIP = av_calloc(w * h, sizeof(float)); \
> \
> - A = av_calloc(width * height, sizeof(float)); \
> - B = av_calloc(width * height, sizeof(float)); \
> - meanA = av_calloc(width * height, sizeof(float)); \
> - meanB = av_calloc(width * height, sizeof(float)); \
> + A = av_calloc(w * h, sizeof(float)); \
> + B = av_calloc(w * h, sizeof(float)); \
> + meanA = av_calloc(w * h, sizeof(float)); \
> + meanB = av_calloc(w * h, sizeof(float)); \
> \
> if (!I || !II || !P || !IP || !meanI || !meanII || !meanP || \
> !meanIP || !A || !B || !meanA || !meanB){ \
> ret = AVERROR(ENOMEM); \
> goto end; \
> } \
> - for (int i = 0;i < height;i++) { \
> - for (int j = 0;j < width;j++) { \
> - int x = i * width + j; \
> - I[x] = src[i * src_stride + j] / maxval; \
> + for (int i = 0;i < h;i++) { \
> + for (int j = 0;j < w;j++) { \
> + int x = i * w + j; \
> + I[x] = src[(i * src_stride + j) * sub] / maxval; \
> II[x] = I[x] * I[x]; \
> - P[x] = srcRef[i * src_ref_stride + j] / maxval; \
> + P[x] = srcRef[(i * src_ref_stride + j) * sub] / maxval; \
> IP[x] = I[x] * P[x]; \
> } \
> } \
> \
> - t.width = width; \
> - t.height = height; \
> - t.srcStride = width; \
> - t.dstStride = width; \
> + t.width = w; \
> + t.height = h; \
> + t.srcStride = w; \
> + t.dstStride = w; \
> t.src = I; \
> t.dst = meanI; \
> - ctx->internal->execute(ctx, s->box_slice, &t, NULL, FFMIN(height, nb_threads)); \
> + ctx->internal->execute(ctx, s->box_slice, &t, NULL, FFMIN(h, nb_threads)); \
> t.src = II; \
> t.dst = meanII; \
> - ctx->internal->execute(ctx, s->box_slice, &t, NULL, FFMIN(height, nb_threads)); \
> + ctx->internal->execute(ctx, s->box_slice, &t, NULL, FFMIN(h, nb_threads)); \
> t.src = P; \
> t.dst = meanP; \
> - ctx->internal->execute(ctx, s->box_slice, &t, NULL, FFMIN(height, nb_threads)); \
> + ctx->internal->execute(ctx, s->box_slice, &t, NULL, FFMIN(h, nb_threads)); \
> t.src = IP; \
> t.dst = meanIP; \
> - ctx->internal->execute(ctx, s->box_slice, &t, NULL, FFMIN(height, nb_threads)); \
> + ctx->internal->execute(ctx, s->box_slice, &t, NULL, FFMIN(h, nb_threads)); \
> \
> - for (int i = 0;i < height;i++) { \
> - for (int j = 0;j < width;j++) { \
> - int x = i * width + j; \
> + for (int i = 0;i < h;i++) { \
> + for (int j = 0;j < w;j++) { \
> + int x = i * w + j; \
> float varI = meanII[x] - (meanI[x] * meanI[x]); \
> float covIP = meanIP[x] - (meanI[x] * meanP[x]); \
> A[x] = covIP / (varI + eps); \
> @@ -247,14 +283,14 @@ static int guided_##name(AVFilterContext *ctx, GuidedContext *s,
> \
> t.src = A; \
> t.dst = meanA; \
> - ctx->internal->execute(ctx, s->box_slice, &t, NULL, FFMIN(height, nb_threads)); \
> + ctx->internal->execute(ctx, s->box_slice, &t, NULL, FFMIN(h, nb_threads)); \
> t.src = B; \
> t.dst = meanB; \
> - ctx->internal->execute(ctx, s->box_slice, &t, NULL, FFMIN(height, nb_threads)); \
> + ctx->internal->execute(ctx, s->box_slice, &t, NULL, FFMIN(h, nb_threads)); \
> \
> for (int i = 0;i < height;i++) { \
> for (int j = 0;j < width;j++) { \
> - int x = i * width + j; \
> + int x = i / sub * w + j / sub; \
> dst[i * dst_stride + j] = meanA[x] * src[i * src_stride + j] + \
> meanB[x] * maxval; \
> } \
> --
> 1.9.1
I think you submit version4 - version3 diff part for fast mode, it's
strange, you need to submit a full version 4 patch
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