float sum;
};
-#define WEIGHT_LUT_NBITS 9
-#define WEIGHT_LUT_SIZE (1<<WEIGHT_LUT_NBITS)
-
typedef struct NLMeansContext {
const AVClass *class;
int nb_planes;
ptrdiff_t ii_lz_32; // linesize in 32-bit units of the integral image
struct weighted_avg *wa; // weighted average of every pixel
ptrdiff_t wa_linesize; // linesize for wa in struct size unit
- float weight_lut[WEIGHT_LUT_SIZE]; // lookup table mapping (scaled) patch differences to their associated weights
- float pdiff_lut_scale; // scale factor for patch differences before looking into the LUT
+ float *weight_lut; // lookup table mapping (scaled) patch differences to their associated weights
uint32_t max_meaningful_diff; // maximum difference considered (if the patch difference is too high we ignore the pixel)
NLMeansDSPContext dsp;
} NLMeansContext;
const uint32_t patch_diff_sq = e - d - b + a;
if (patch_diff_sq < s->max_meaningful_diff) {
- const unsigned weight_lut_idx = patch_diff_sq * s->pdiff_lut_scale;
- const float weight = s->weight_lut[weight_lut_idx]; // exp(-patch_diff_sq * s->pdiff_scale)
+ const float weight = s->weight_lut[patch_diff_sq]; // exp(-patch_diff_sq * s->pdiff_scale)
wa[x].total_weight += weight;
wa[x].sum += weight * src[x];
}
// Also weight the centered pixel
wa[x].total_weight += 1.f;
wa[x].sum += 1.f * src[x];
- dst[x] = av_clip_uint8(wa[x].sum / wa[x].total_weight);
+ dst[x] = av_clip_uint8(wa[x].sum / wa[x].total_weight + 0.5f);
}
dst += dst_linesize;
src += src_linesize;
const double h = s->sigma * 10.;
s->pdiff_scale = 1. / (h * h);
- s->max_meaningful_diff = -log(1/255.) / s->pdiff_scale;
- s->pdiff_lut_scale = 1./s->max_meaningful_diff * WEIGHT_LUT_SIZE;
- av_assert0((s->max_meaningful_diff - 1) * s->pdiff_lut_scale < FF_ARRAY_ELEMS(s->weight_lut));
- for (i = 0; i < WEIGHT_LUT_SIZE; i++)
- s->weight_lut[i] = exp(-i / s->pdiff_lut_scale * s->pdiff_scale);
+ s->max_meaningful_diff = log(255.) / s->pdiff_scale;
+ s->weight_lut = av_calloc(s->max_meaningful_diff, sizeof(*s->weight_lut));
+ if (!s->weight_lut)
+ return AVERROR(ENOMEM);
+ for (i = 0; i < s->max_meaningful_diff; i++)
+ s->weight_lut[i] = exp(-i * s->pdiff_scale);
CHECK_ODD_FIELD(research_size, "Luma research window");
CHECK_ODD_FIELD(patch_size, "Luma patch");
static av_cold void uninit(AVFilterContext *ctx)
{
NLMeansContext *s = ctx->priv;
+ av_freep(&s->weight_lut);
av_freep(&s->ii_orig);
av_freep(&s->wa);
}
{ NULL }
};
-AVFilter ff_vf_nlmeans = {
+const AVFilter ff_vf_nlmeans = {
.name = "nlmeans",
.description = NULL_IF_CONFIG_SMALL("Non-local means denoiser."),
.priv_size = sizeof(NLMeansContext),