| /* |
| * Copyright (c) 2012 The WebM project authors. All Rights Reserved. |
| * |
| * Use of this source code is governed by a BSD-style license |
| * that can be found in the LICENSE file in the root of the source |
| * tree. An additional intellectual property rights grant can be found |
| * in the file PATENTS. All contributing project authors may |
| * be found in the AUTHORS file in the root of the source tree. |
| */ |
| |
| #include "denoising.h" |
| |
| #include "vp8/common/reconinter.h" |
| #include "vpx/vpx_integer.h" |
| #include "vpx_mem/vpx_mem.h" |
| #include "vp8_rtcd.h" |
| |
| static const unsigned int NOISE_MOTION_THRESHOLD = 25 * 25; |
| /* SSE_DIFF_THRESHOLD is selected as ~95% confidence assuming |
| * var(noise) ~= 100. |
| */ |
| static const unsigned int SSE_DIFF_THRESHOLD = 16 * 16 * 20; |
| static const unsigned int SSE_THRESHOLD = 16 * 16 * 40; |
| static const unsigned int SSE_THRESHOLD_HIGH = 16 * 16 * 60; |
| |
| /* |
| * The filter function was modified to reduce the computational complexity. |
| * Step 1: |
| * Instead of applying tap coefficients for each pixel, we calculated the |
| * pixel adjustments vs. pixel diff value ahead of time. |
| * adjustment = filtered_value - current_raw |
| * = (filter_coefficient * diff + 128) >> 8 |
| * where |
| * filter_coefficient = (255 << 8) / (256 + ((absdiff * 330) >> 3)); |
| * filter_coefficient += filter_coefficient / |
| * (3 + motion_magnitude_adjustment); |
| * filter_coefficient is clamped to 0 ~ 255. |
| * |
| * Step 2: |
| * The adjustment vs. diff curve becomes flat very quick when diff increases. |
| * This allowed us to use only several levels to approximate the curve without |
| * changing the filtering algorithm too much. |
| * The adjustments were further corrected by checking the motion magnitude. |
| * The levels used are: |
| * diff adjustment w/o motion correction adjustment w/ motion correction |
| * [-255, -16] -6 -7 |
| * [-15, -8] -4 -5 |
| * [-7, -4] -3 -4 |
| * [-3, 3] diff diff |
| * [4, 7] 3 4 |
| * [8, 15] 4 5 |
| * [16, 255] 6 7 |
| */ |
| |
| int vp8_denoiser_filter_c(unsigned char *mc_running_avg_y, int mc_avg_y_stride, |
| unsigned char *running_avg_y, int avg_y_stride, |
| unsigned char *sig, int sig_stride, |
| unsigned int motion_magnitude, |
| int increase_denoising) |
| { |
| unsigned char *running_avg_y_start = running_avg_y; |
| unsigned char *sig_start = sig; |
| int sum_diff_thresh; |
| int r, c; |
| int sum_diff = 0; |
| int adj_val[3] = {3, 4, 6}; |
| int shift_inc1 = 0; |
| int shift_inc2 = 1; |
| /* If motion_magnitude is small, making the denoiser more aggressive by |
| * increasing the adjustment for each level. Add another increment for |
| * blocks that are labeled for increase denoising. */ |
| if (motion_magnitude <= MOTION_MAGNITUDE_THRESHOLD) |
| { |
| if (increase_denoising) { |
| shift_inc1 = 1; |
| shift_inc2 = 2; |
| } |
| adj_val[0] += shift_inc2; |
| adj_val[1] += shift_inc2; |
| adj_val[2] += shift_inc2; |
| } |
| |
| for (r = 0; r < 16; ++r) |
| { |
| for (c = 0; c < 16; ++c) |
| { |
| int diff = 0; |
| int adjustment = 0; |
| int absdiff = 0; |
| |
| diff = mc_running_avg_y[c] - sig[c]; |
| absdiff = abs(diff); |
| |
| // When |diff| <= |3 + shift_inc1|, use pixel value from |
| // last denoised raw. |
| if (absdiff <= 3 + shift_inc1) |
| { |
| running_avg_y[c] = mc_running_avg_y[c]; |
| sum_diff += diff; |
| } |
| else |
| { |
| if (absdiff >= 4 && absdiff <= 7) |
| adjustment = adj_val[0]; |
| else if (absdiff >= 8 && absdiff <= 15) |
| adjustment = adj_val[1]; |
| else |
| adjustment = adj_val[2]; |
| |
| if (diff > 0) |
| { |
| if ((sig[c] + adjustment) > 255) |
| running_avg_y[c] = 255; |
| else |
| running_avg_y[c] = sig[c] + adjustment; |
| |
| sum_diff += adjustment; |
| } |
| else |
| { |
| if ((sig[c] - adjustment) < 0) |
| running_avg_y[c] = 0; |
| else |
| running_avg_y[c] = sig[c] - adjustment; |
| |
| sum_diff -= adjustment; |
| } |
| } |
| } |
| |
| /* Update pointers for next iteration. */ |
| sig += sig_stride; |
| mc_running_avg_y += mc_avg_y_stride; |
| running_avg_y += avg_y_stride; |
| } |
| |
| sum_diff_thresh= SUM_DIFF_THRESHOLD; |
| if (increase_denoising) sum_diff_thresh = SUM_DIFF_THRESHOLD_HIGH; |
| if (abs(sum_diff) > sum_diff_thresh) { |
| // Before returning to copy the block (i.e., apply no denoising), check |
| // if we can still apply some (weaker) temporal filtering to this block, |
| // that would otherwise not be denoised at all. Simplest is to apply |
| // an additional adjustment to running_avg_y to bring it closer to sig. |
| // The adjustment is capped by a maximum delta, and chosen such that |
| // in most cases the resulting sum_diff will be within the |
| // accceptable range given by sum_diff_thresh. |
| |
| // The delta is set by the excess of absolute pixel diff over threshold. |
| int delta = ((abs(sum_diff) - sum_diff_thresh) >> 8) + 1; |
| // Only apply the adjustment for max delta up to 3. |
| if (delta < 4) { |
| sig -= sig_stride * 16; |
| mc_running_avg_y -= mc_avg_y_stride * 16; |
| running_avg_y -= avg_y_stride * 16; |
| for (r = 0; r < 16; ++r) { |
| for (c = 0; c < 16; ++c) { |
| int diff = mc_running_avg_y[c] - sig[c]; |
| int adjustment = abs(diff); |
| if (adjustment > delta) |
| adjustment = delta; |
| if (diff > 0) { |
| // Bring denoised signal down. |
| if (running_avg_y[c] - adjustment < 0) |
| running_avg_y[c] = 0; |
| else |
| running_avg_y[c] = running_avg_y[c] - adjustment; |
| sum_diff -= adjustment; |
| } else if (diff < 0) { |
| // Bring denoised signal up. |
| if (running_avg_y[c] + adjustment > 255) |
| running_avg_y[c] = 255; |
| else |
| running_avg_y[c] = running_avg_y[c] + adjustment; |
| sum_diff += adjustment; |
| } |
| } |
| // TODO(marpan): Check here if abs(sum_diff) has gone below the |
| // threshold sum_diff_thresh, and if so, we can exit the row loop. |
| sig += sig_stride; |
| mc_running_avg_y += mc_avg_y_stride; |
| running_avg_y += avg_y_stride; |
| } |
| if (abs(sum_diff) > sum_diff_thresh) |
| return COPY_BLOCK; |
| } else { |
| return COPY_BLOCK; |
| } |
| } |
| |
| vp8_copy_mem16x16(running_avg_y_start, avg_y_stride, sig_start, sig_stride); |
| return FILTER_BLOCK; |
| } |
| |
| int vp8_denoiser_allocate(VP8_DENOISER *denoiser, int width, int height) |
| { |
| int i; |
| assert(denoiser); |
| |
| for (i = 0; i < MAX_REF_FRAMES; i++) |
| { |
| denoiser->yv12_running_avg[i].flags = 0; |
| |
| if (vp8_yv12_alloc_frame_buffer(&(denoiser->yv12_running_avg[i]), width, |
| height, VP8BORDERINPIXELS) |
| < 0) |
| { |
| vp8_denoiser_free(denoiser); |
| return 1; |
| } |
| vpx_memset(denoiser->yv12_running_avg[i].buffer_alloc, 0, |
| denoiser->yv12_running_avg[i].frame_size); |
| |
| } |
| denoiser->yv12_mc_running_avg.flags = 0; |
| |
| if (vp8_yv12_alloc_frame_buffer(&(denoiser->yv12_mc_running_avg), width, |
| height, VP8BORDERINPIXELS) < 0) |
| { |
| vp8_denoiser_free(denoiser); |
| return 1; |
| } |
| |
| vpx_memset(denoiser->yv12_mc_running_avg.buffer_alloc, 0, |
| denoiser->yv12_mc_running_avg.frame_size); |
| return 0; |
| } |
| |
| void vp8_denoiser_free(VP8_DENOISER *denoiser) |
| { |
| int i; |
| assert(denoiser); |
| |
| for (i = 0; i < MAX_REF_FRAMES ; i++) |
| { |
| vp8_yv12_de_alloc_frame_buffer(&denoiser->yv12_running_avg[i]); |
| } |
| vp8_yv12_de_alloc_frame_buffer(&denoiser->yv12_mc_running_avg); |
| } |
| |
| |
| void vp8_denoiser_denoise_mb(VP8_DENOISER *denoiser, |
| MACROBLOCK *x, |
| unsigned int best_sse, |
| unsigned int zero_mv_sse, |
| int recon_yoffset, |
| int recon_uvoffset) |
| { |
| int mv_row; |
| int mv_col; |
| unsigned int motion_magnitude2; |
| unsigned int sse_thresh; |
| MV_REFERENCE_FRAME frame = x->best_reference_frame; |
| MV_REFERENCE_FRAME zero_frame = x->best_zeromv_reference_frame; |
| |
| enum vp8_denoiser_decision decision = FILTER_BLOCK; |
| |
| if (zero_frame) |
| { |
| YV12_BUFFER_CONFIG *src = &denoiser->yv12_running_avg[frame]; |
| YV12_BUFFER_CONFIG *dst = &denoiser->yv12_mc_running_avg; |
| YV12_BUFFER_CONFIG saved_pre,saved_dst; |
| MB_MODE_INFO saved_mbmi; |
| MACROBLOCKD *filter_xd = &x->e_mbd; |
| MB_MODE_INFO *mbmi = &filter_xd->mode_info_context->mbmi; |
| int sse_diff = zero_mv_sse - best_sse; |
| |
| saved_mbmi = *mbmi; |
| |
| /* Use the best MV for the compensation. */ |
| mbmi->ref_frame = x->best_reference_frame; |
| mbmi->mode = x->best_sse_inter_mode; |
| mbmi->mv = x->best_sse_mv; |
| mbmi->need_to_clamp_mvs = x->need_to_clamp_best_mvs; |
| mv_col = x->best_sse_mv.as_mv.col; |
| mv_row = x->best_sse_mv.as_mv.row; |
| |
| if (frame == INTRA_FRAME || |
| ((unsigned int)(mv_row *mv_row + mv_col *mv_col) |
| <= NOISE_MOTION_THRESHOLD && |
| sse_diff < (int)SSE_DIFF_THRESHOLD)) |
| { |
| /* |
| * Handle intra blocks as referring to last frame with zero motion |
| * and let the absolute pixel difference affect the filter factor. |
| * Also consider small amount of motion as being random walk due |
| * to noise, if it doesn't mean that we get a much bigger error. |
| * Note that any changes to the mode info only affects the |
| * denoising. |
| */ |
| mbmi->ref_frame = |
| x->best_zeromv_reference_frame; |
| |
| src = &denoiser->yv12_running_avg[zero_frame]; |
| |
| mbmi->mode = ZEROMV; |
| mbmi->mv.as_int = 0; |
| x->best_sse_inter_mode = ZEROMV; |
| x->best_sse_mv.as_int = 0; |
| best_sse = zero_mv_sse; |
| } |
| |
| saved_pre = filter_xd->pre; |
| saved_dst = filter_xd->dst; |
| |
| /* Compensate the running average. */ |
| filter_xd->pre.y_buffer = src->y_buffer + recon_yoffset; |
| filter_xd->pre.u_buffer = src->u_buffer + recon_uvoffset; |
| filter_xd->pre.v_buffer = src->v_buffer + recon_uvoffset; |
| /* Write the compensated running average to the destination buffer. */ |
| filter_xd->dst.y_buffer = dst->y_buffer + recon_yoffset; |
| filter_xd->dst.u_buffer = dst->u_buffer + recon_uvoffset; |
| filter_xd->dst.v_buffer = dst->v_buffer + recon_uvoffset; |
| |
| if (!x->skip) |
| { |
| vp8_build_inter_predictors_mb(filter_xd); |
| } |
| else |
| { |
| vp8_build_inter16x16_predictors_mb(filter_xd, |
| filter_xd->dst.y_buffer, |
| filter_xd->dst.u_buffer, |
| filter_xd->dst.v_buffer, |
| filter_xd->dst.y_stride, |
| filter_xd->dst.uv_stride); |
| } |
| filter_xd->pre = saved_pre; |
| filter_xd->dst = saved_dst; |
| *mbmi = saved_mbmi; |
| |
| } |
| |
| mv_row = x->best_sse_mv.as_mv.row; |
| mv_col = x->best_sse_mv.as_mv.col; |
| motion_magnitude2 = mv_row * mv_row + mv_col * mv_col; |
| sse_thresh = SSE_THRESHOLD; |
| if (x->increase_denoising) sse_thresh = SSE_THRESHOLD_HIGH; |
| |
| if (best_sse > sse_thresh || motion_magnitude2 |
| > 8 * NOISE_MOTION_THRESHOLD) |
| { |
| decision = COPY_BLOCK; |
| } |
| |
| if (decision == FILTER_BLOCK) |
| { |
| unsigned char *mc_running_avg_y = |
| denoiser->yv12_mc_running_avg.y_buffer + recon_yoffset; |
| int mc_avg_y_stride = denoiser->yv12_mc_running_avg.y_stride; |
| unsigned char *running_avg_y = |
| denoiser->yv12_running_avg[INTRA_FRAME].y_buffer + recon_yoffset; |
| int avg_y_stride = denoiser->yv12_running_avg[INTRA_FRAME].y_stride; |
| |
| /* Filter. */ |
| decision = vp8_denoiser_filter(mc_running_avg_y, mc_avg_y_stride, |
| running_avg_y, avg_y_stride, |
| x->thismb, 16, motion_magnitude2, |
| x->increase_denoising); |
| } |
| if (decision == COPY_BLOCK) |
| { |
| /* No filtering of this block; it differs too much from the predictor, |
| * or the motion vector magnitude is considered too big. |
| */ |
| vp8_copy_mem16x16( |
| x->thismb, 16, |
| denoiser->yv12_running_avg[INTRA_FRAME].y_buffer + recon_yoffset, |
| denoiser->yv12_running_avg[INTRA_FRAME].y_stride); |
| } |
| } |
