| Line | Branch | Exec | Source |
|---|---|---|---|
| 1 | /* | ||
| 2 | * Copyright (c) 2021 Paul Buxton | ||
| 3 | * | ||
| 4 | * This file is part of FFmpeg. | ||
| 5 | * | ||
| 6 | * FFmpeg is free software; you can redistribute it and/or | ||
| 7 | * modify it under the terms of the GNU Lesser General Public | ||
| 8 | * License as published by the Free Software Foundation; either | ||
| 9 | * version 2.1 of the License, or (at your option) any later version. | ||
| 10 | * | ||
| 11 | * FFmpeg is distributed in the hope that it will be useful, | ||
| 12 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | ||
| 13 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | ||
| 14 | * Lesser General Public License for more details. | ||
| 15 | * | ||
| 16 | * You should have received a copy of the GNU Lesser General Public | ||
| 17 | * License along with FFmpeg; if not, write to the Free Software | ||
| 18 | * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA | ||
| 19 | */ | ||
| 20 | |||
| 21 | /** | ||
| 22 | * @file | ||
| 23 | * Color correction filter based on | ||
| 24 | * https://www.researchgate.net/publication/275213614_A_New_Color_Correction_Method_for_Underwater_Imaging | ||
| 25 | * | ||
| 26 | */ | ||
| 27 | |||
| 28 | #include "libavutil/imgutils.h" | ||
| 29 | #include "libavutil/mem.h" | ||
| 30 | |||
| 31 | #include "avfilter.h" | ||
| 32 | #include "filters.h" | ||
| 33 | #include "video.h" | ||
| 34 | |||
| 35 | typedef struct ThreadData { | ||
| 36 | AVFrame *in, *out; | ||
| 37 | float l_avg; | ||
| 38 | float a_avg; | ||
| 39 | float b_avg; | ||
| 40 | } ThreadData; | ||
| 41 | |||
| 42 | typedef struct GrayWorldContext { | ||
| 43 | float *tmpplab; | ||
| 44 | int *line_count_pels; | ||
| 45 | float *line_sum; | ||
| 46 | } GrayWorldContext; | ||
| 47 | |||
| 48 | ✗ | static void apply_matrix(const float matrix[3][3], const float input[3], float output[3]) | |
| 49 | { | ||
| 50 | ✗ | output[0] = matrix[0][0] * input[0] + matrix[0][1] * input[1] + matrix[0][2] * input[2]; | |
| 51 | ✗ | output[1] = matrix[1][0] * input[0] + matrix[1][1] * input[1] + matrix[1][2] * input[2]; | |
| 52 | ✗ | output[2] = matrix[2][0] * input[0] + matrix[2][1] * input[1] + matrix[2][2] * input[2]; | |
| 53 | ✗ | } | |
| 54 | |||
| 55 | static const float lms2lab[3][3] = { | ||
| 56 | {0.5774, 0.5774, 0.5774}, | ||
| 57 | {0.40825, 0.40825, -0.816458}, | ||
| 58 | {0.707, -0.707, 0} | ||
| 59 | }; | ||
| 60 | |||
| 61 | static const float lab2lms[3][3] = { | ||
| 62 | {0.57735, 0.40825, 0.707}, | ||
| 63 | {0.57735, 0.40825, -0.707}, | ||
| 64 | {0.57735, -0.8165, 0} | ||
| 65 | }; | ||
| 66 | |||
| 67 | static const float rgb2lms[3][3] = { | ||
| 68 | {0.3811, 0.5783, 0.0402}, | ||
| 69 | {0.1967, 0.7244, 0.0782}, | ||
| 70 | {0.0241, 0.1288, 0.8444} | ||
| 71 | }; | ||
| 72 | |||
| 73 | static const float lms2rgb[3][3] = { | ||
| 74 | {4.4679, -3.5873, 0.1193}, | ||
| 75 | {-1.2186, 2.3809, -0.1624}, | ||
| 76 | {0.0497, -0.2439, 1.2045} | ||
| 77 | }; | ||
| 78 | |||
| 79 | /** | ||
| 80 | * Convert from Linear RGB to logspace LAB | ||
| 81 | * | ||
| 82 | * @param rgb Input array of rgb components | ||
| 83 | * @param lab output array of lab components | ||
| 84 | */ | ||
| 85 | ✗ | static void rgb2lab(const float rgb[3], float lab[3]) | |
| 86 | { | ||
| 87 | float lms[3]; | ||
| 88 | |||
| 89 | ✗ | apply_matrix(rgb2lms, rgb, lms); | |
| 90 | ✗ | lms[0] = lms[0] > 0.f ? logf(lms[0]) : -1024.f; | |
| 91 | ✗ | lms[1] = lms[1] > 0.f ? logf(lms[1]) : -1024.f; | |
| 92 | ✗ | lms[2] = lms[2] > 0.f ? logf(lms[2]) : -1024.f; | |
| 93 | ✗ | apply_matrix(lms2lab, lms, lab); | |
| 94 | ✗ | } | |
| 95 | |||
| 96 | /** | ||
| 97 | * Convert from Logspace LAB to Linear RGB | ||
| 98 | * | ||
| 99 | * @param lab input array of lab components | ||
| 100 | * @param rgb output array of rgb components | ||
| 101 | */ | ||
| 102 | ✗ | static void lab2rgb(const float lab[3], float rgb[3]) | |
| 103 | { | ||
| 104 | float lms[3]; | ||
| 105 | |||
| 106 | ✗ | apply_matrix(lab2lms, lab, lms); | |
| 107 | ✗ | lms[0] = expf(lms[0]); | |
| 108 | ✗ | lms[1] = expf(lms[1]); | |
| 109 | ✗ | lms[2] = expf(lms[2]); | |
| 110 | ✗ | apply_matrix(lms2rgb, lms, rgb); | |
| 111 | ✗ | } | |
| 112 | |||
| 113 | /** | ||
| 114 | * Convert a frame from linear RGB to logspace LAB, and accumulate channel totals for each row | ||
| 115 | * Convert from RGB -> lms using equation 4 in color transfer paper. | ||
| 116 | * | ||
| 117 | * @param ctx Filter context | ||
| 118 | * @param arg Thread data pointer | ||
| 119 | * @param jobnr job number | ||
| 120 | * @param nb_jobs number of jobs | ||
| 121 | */ | ||
| 122 | ✗ | static int convert_frame(AVFilterContext *ctx, void *arg, int jobnr, int nb_jobs) | |
| 123 | { | ||
| 124 | ✗ | GrayWorldContext *s = ctx->priv; | |
| 125 | ✗ | ThreadData *td = arg; | |
| 126 | ✗ | AVFrame *in = td->in; | |
| 127 | ✗ | AVFrame *out = td->out; | |
| 128 | ✗ | AVFilterLink *outlink = ctx->outputs[0]; | |
| 129 | ✗ | const int slice_start = (out->height * jobnr) / nb_jobs; | |
| 130 | ✗ | const int slice_end = (out->height * (jobnr + 1)) / nb_jobs; | |
| 131 | float rgb[3], lab[3]; | ||
| 132 | |||
| 133 | ✗ | for (int i = slice_start; i < slice_end; i++) { | |
| 134 | ✗ | float *b_in_row = (float *)(in->data[1] + i * in->linesize[1]); | |
| 135 | ✗ | float *g_in_row = (float *)(in->data[0] + i * in->linesize[0]); | |
| 136 | ✗ | float *r_in_row = (float *)(in->data[2] + i * in->linesize[2]); | |
| 137 | ✗ | float *acur = s->tmpplab + i * outlink->w + outlink->w * outlink->h; | |
| 138 | ✗ | float *bcur = s->tmpplab + i * outlink->w + 2 * outlink->w * outlink->h; | |
| 139 | ✗ | float *lcur = s->tmpplab + i * outlink->w; | |
| 140 | |||
| 141 | ✗ | s->line_sum[i] = 0.f; | |
| 142 | ✗ | s->line_sum[i + outlink->h] = 0.f; | |
| 143 | ✗ | s->line_count_pels[i] = 0; | |
| 144 | |||
| 145 | ✗ | for (int j = 0; j < outlink->w; j++) { | |
| 146 | ✗ | rgb[0] = r_in_row[j]; | |
| 147 | ✗ | rgb[1] = g_in_row[j]; | |
| 148 | ✗ | rgb[2] = b_in_row[j]; | |
| 149 | ✗ | rgb2lab(rgb, lab); | |
| 150 | ✗ | *(lcur++) = lab[0]; | |
| 151 | ✗ | *(acur++) = lab[1]; | |
| 152 | ✗ | *(bcur++) = lab[2]; | |
| 153 | ✗ | s->line_sum[i] += lab[1]; | |
| 154 | ✗ | s->line_sum[i + outlink->h] += lab[2]; | |
| 155 | ✗ | s->line_count_pels[i]++; | |
| 156 | } | ||
| 157 | } | ||
| 158 | ✗ | return 0; | |
| 159 | } | ||
| 160 | |||
| 161 | /** | ||
| 162 | * Sum the channel totals and compute the mean for each channel | ||
| 163 | * | ||
| 164 | * @param s Frame context | ||
| 165 | * @param td thread data | ||
| 166 | */ | ||
| 167 | ✗ | static void compute_correction(GrayWorldContext *s, ThreadData *td) | |
| 168 | { | ||
| 169 | ✗ | float asum = 0.f, bsum = 0.f; | |
| 170 | ✗ | int pixels = 0; | |
| 171 | |||
| 172 | ✗ | for (int y = 0; y < td->out->height; y++) { | |
| 173 | ✗ | asum += s->line_sum[y]; | |
| 174 | ✗ | bsum += s->line_sum[y + td->out->height]; | |
| 175 | ✗ | pixels += s->line_count_pels[y]; | |
| 176 | } | ||
| 177 | |||
| 178 | ✗ | td->a_avg = asum / pixels; | |
| 179 | ✗ | td->b_avg = bsum / pixels; | |
| 180 | ✗ | } | |
| 181 | |||
| 182 | /** | ||
| 183 | * Subtract the mean logspace AB values from each pixel. | ||
| 184 | * | ||
| 185 | * @param ctx Filter context | ||
| 186 | * @param arg Thread data pointer | ||
| 187 | * @param jobnr job number | ||
| 188 | * @param nb_jobs number of jobs | ||
| 189 | */ | ||
| 190 | ✗ | static int correct_frame(AVFilterContext *ctx, void *arg, int jobnr, int nb_jobs) | |
| 191 | { | ||
| 192 | ✗ | GrayWorldContext *s = ctx->priv; | |
| 193 | ✗ | ThreadData *td = arg; | |
| 194 | ✗ | AVFrame *out = td->out; | |
| 195 | ✗ | AVFilterLink *outlink = ctx->outputs[0]; | |
| 196 | ✗ | const int slice_start = (out->height * jobnr) / nb_jobs; | |
| 197 | ✗ | const int slice_end = (out->height * (jobnr + 1)) / nb_jobs; | |
| 198 | float rgb[3], lab[3]; | ||
| 199 | |||
| 200 | ✗ | for (int i = slice_start; i < slice_end; i++) { | |
| 201 | ✗ | float *g_out_row = (float *)(out->data[0] + i * out->linesize[0]); | |
| 202 | ✗ | float *b_out_row = (float *)(out->data[1] + i * out->linesize[1]); | |
| 203 | ✗ | float *r_out_row = (float *)(out->data[2] + i * out->linesize[2]); | |
| 204 | ✗ | float *lcur = s->tmpplab + i * outlink->w; | |
| 205 | ✗ | float *acur = s->tmpplab + i * outlink->w + outlink->w * outlink->h; | |
| 206 | ✗ | float *bcur = s->tmpplab + i * outlink->w + 2 * outlink->w * outlink->h; | |
| 207 | |||
| 208 | ✗ | for (int j = 0; j < outlink->w; j++) { | |
| 209 | ✗ | lab[0] = *lcur++; | |
| 210 | ✗ | lab[1] = *acur++; | |
| 211 | ✗ | lab[2] = *bcur++; | |
| 212 | |||
| 213 | // subtract the average for the color channels | ||
| 214 | ✗ | lab[1] -= td->a_avg; | |
| 215 | ✗ | lab[2] -= td->b_avg; | |
| 216 | |||
| 217 | //convert back to linear rgb | ||
| 218 | ✗ | lab2rgb(lab, rgb); | |
| 219 | ✗ | r_out_row[j] = rgb[0]; | |
| 220 | ✗ | g_out_row[j] = rgb[1]; | |
| 221 | ✗ | b_out_row[j] = rgb[2]; | |
| 222 | } | ||
| 223 | } | ||
| 224 | ✗ | return 0; | |
| 225 | } | ||
| 226 | |||
| 227 | ✗ | static int config_input(AVFilterLink *inlink) | |
| 228 | { | ||
| 229 | ✗ | GrayWorldContext *s = inlink->dst->priv; | |
| 230 | |||
| 231 | ✗ | FF_ALLOC_TYPED_ARRAY(s->tmpplab, inlink->h * inlink->w * 3); | |
| 232 | ✗ | FF_ALLOC_TYPED_ARRAY(s->line_count_pels, inlink->h); | |
| 233 | ✗ | FF_ALLOC_TYPED_ARRAY(s->line_sum, inlink->h * 2); | |
| 234 | ✗ | if (!s->tmpplab || !s->line_count_pels || !s->line_sum) | |
| 235 | ✗ | return AVERROR(ENOMEM); | |
| 236 | |||
| 237 | ✗ | return 0; | |
| 238 | } | ||
| 239 | |||
| 240 | ✗ | static av_cold void uninit(AVFilterContext *ctx) | |
| 241 | { | ||
| 242 | ✗ | GrayWorldContext *s = ctx->priv; | |
| 243 | |||
| 244 | ✗ | av_freep(&s->tmpplab); | |
| 245 | ✗ | av_freep(&s->line_count_pels); | |
| 246 | ✗ | av_freep(&s->line_sum); | |
| 247 | ✗ | } | |
| 248 | |||
| 249 | ✗ | static int filter_frame(AVFilterLink *inlink, AVFrame *in) | |
| 250 | { | ||
| 251 | ✗ | AVFilterContext *ctx = inlink->dst; | |
| 252 | ✗ | GrayWorldContext *s = ctx->priv; | |
| 253 | ✗ | AVFilterLink *outlink = ctx->outputs[0]; | |
| 254 | ThreadData td; | ||
| 255 | AVFrame *out; | ||
| 256 | |||
| 257 | ✗ | if (av_frame_is_writable(in)) { | |
| 258 | ✗ | out = in; | |
| 259 | } else { | ||
| 260 | ✗ | out = ff_get_video_buffer(outlink, outlink->w, outlink->h); | |
| 261 | ✗ | if (!out) { | |
| 262 | ✗ | av_frame_free(&in); | |
| 263 | ✗ | return AVERROR(ENOMEM); | |
| 264 | } | ||
| 265 | ✗ | av_frame_copy_props(out, in); | |
| 266 | } | ||
| 267 | /* input and output transfer will be linear */ | ||
| 268 | ✗ | if (in->color_trc == AVCOL_TRC_UNSPECIFIED) { | |
| 269 | ✗ | av_log(s, AV_LOG_WARNING, "Untagged transfer, assuming linear light.\n"); | |
| 270 | ✗ | out->color_trc = AVCOL_TRC_LINEAR; | |
| 271 | ✗ | } else if (in->color_trc != AVCOL_TRC_LINEAR) { | |
| 272 | ✗ | av_log(s, AV_LOG_WARNING, "Gray world color correction works on linear light only.\n"); | |
| 273 | } | ||
| 274 | |||
| 275 | ✗ | td.in = in; | |
| 276 | ✗ | td.out = out; | |
| 277 | |||
| 278 | ✗ | ff_filter_execute(ctx, convert_frame, &td, NULL, FFMIN(outlink->h, ff_filter_get_nb_threads(ctx))); | |
| 279 | ✗ | compute_correction(s, &td); | |
| 280 | ✗ | ff_filter_execute(ctx, correct_frame, &td, NULL, FFMIN(outlink->h, ff_filter_get_nb_threads(ctx))); | |
| 281 | |||
| 282 | ✗ | if (in != out) { | |
| 283 | ✗ | av_image_copy_plane(out->data[3], out->linesize[3], | |
| 284 | ✗ | in->data[3], in->linesize[3], outlink->w * 4, outlink->h); | |
| 285 | ✗ | av_frame_free(&in); | |
| 286 | } | ||
| 287 | |||
| 288 | ✗ | return ff_filter_frame(outlink, out); | |
| 289 | } | ||
| 290 | |||
| 291 | static const AVFilterPad grayworld_inputs[] = { | ||
| 292 | { | ||
| 293 | .name = "default", | ||
| 294 | .type = AVMEDIA_TYPE_VIDEO, | ||
| 295 | .filter_frame = filter_frame, | ||
| 296 | .config_props = config_input, | ||
| 297 | } | ||
| 298 | }; | ||
| 299 | |||
| 300 | const AVFilter ff_vf_grayworld = { | ||
| 301 | .name = "grayworld", | ||
| 302 | .description = NULL_IF_CONFIG_SMALL("Adjust white balance using LAB gray world algorithm"), | ||
| 303 | .priv_size = sizeof(GrayWorldContext), | ||
| 304 | FILTER_INPUTS(grayworld_inputs), | ||
| 305 | FILTER_OUTPUTS(ff_video_default_filterpad), | ||
| 306 | FILTER_PIXFMTS(AV_PIX_FMT_GBRPF32, AV_PIX_FMT_GBRAPF32), | ||
| 307 | .flags = AVFILTER_FLAG_SUPPORT_TIMELINE_GENERIC | AVFILTER_FLAG_SLICE_THREADS, | ||
| 308 | .uninit = uninit, | ||
| 309 | }; | ||
| 310 |