[FFmpeg-cvslog] avcodec/tiff: improve color handling in DNG
Paul B Mahol
git at videolan.org
Sun Sep 25 19:33:19 EEST 2022
ffmpeg | branch: master | Paul B Mahol <onemda at gmail.com> | Sun Sep 25 14:59:32 2022 +0200| [91897110b012dbad18c54de169569ab6eb47af4b] | committer: Paul B Mahol
avcodec/tiff: improve color handling in DNG
> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=91897110b012dbad18c54de169569ab6eb47af4b
---
libavcodec/tiff.c | 204 ++++++++++++++++++++++++++++++++++++++++++++++++++----
libavcodec/tiff.h | 7 ++
2 files changed, 199 insertions(+), 12 deletions(-)
diff --git a/libavcodec/tiff.c b/libavcodec/tiff.c
index 750c42ca51..302444cb0f 100644
--- a/libavcodec/tiff.c
+++ b/libavcodec/tiff.c
@@ -33,6 +33,8 @@
#include <lzma.h>
#endif
+#include <float.h>
+
#include "libavutil/attributes.h"
#include "libavutil/error.h"
#include "libavutil/intreadwrite.h"
@@ -82,7 +84,16 @@ typedef struct TiffContext {
unsigned last_tag;
int is_bayer;
+ int use_color_matrix;
uint8_t pattern[4];
+
+ float analog_balance[4];
+ float as_shot_neutral[4];
+ float as_shot_white[4];
+ float color_matrix[3][4];
+ float camera_calibration[4][4];
+ float premultiply[4];
+
unsigned black_level;
unsigned white_level;
uint16_t dng_lut[65536];
@@ -112,6 +123,8 @@ typedef struct TiffContext {
TiffGeoTag *geotags;
} TiffContext;
+static const float d65_white[3] = { 0.950456f, 1.f, 1.088754f };
+
static void tiff_set_type(TiffContext *s, enum TiffType tiff_type) {
if (s->tiff_type < tiff_type) // Prioritize higher-valued entries
s->tiff_type = tiff_type;
@@ -286,12 +299,12 @@ static uint16_t av_always_inline dng_process_color16(uint16_t value,
value = lut[value];
// Black level subtraction
- value = av_clip_uint16_c((unsigned)value - black_level);
+ value = av_clip_uint16((unsigned)value - black_level);
// Color scaling
- value_norm = (float)value * scale_factor * 65535.f;
+ value_norm = (float)value * scale_factor;
- value = av_clip_uint16_c(lrintf(value_norm));
+ value = av_clip_uint16(lrintf(value_norm));
return value;
}
@@ -306,12 +319,18 @@ static uint16_t av_always_inline dng_process_color8(uint16_t value,
static void av_always_inline dng_blit(TiffContext *s, uint8_t *dst, int dst_stride,
const uint8_t *src, int src_stride, int width, int height,
- int is_single_comp, int is_u16)
+ int is_single_comp, int is_u16, int odd_line)
{
+ float scale_factor[4];
int line, col;
- float scale_factor;
- scale_factor = 1.0f / (s->white_level - s->black_level);
+ if (s->is_bayer) {
+ for (int i = 0; i < 4; i++)
+ scale_factor[i] = s->premultiply[s->pattern[i]] * 65535.f / (s->white_level - s->black_level);
+ } else {
+ for (int i = 0; i < 4; i++)
+ scale_factor[i] = 65535.f * s->premultiply[i] / (s->white_level - s->black_level);
+ }
if (is_single_comp) {
if (!is_u16)
@@ -325,7 +344,7 @@ static void av_always_inline dng_blit(TiffContext *s, uint8_t *dst, int dst_stri
/* Blit first half of input row row to initial row of output */
for (col = 0; col < width; col++)
- *dst_u16++ = dng_process_color16(*src_u16++, s->dng_lut, s->black_level, scale_factor);
+ *dst_u16++ = dng_process_color16(*src_u16++, s->dng_lut, s->black_level, scale_factor[col&1]);
/* Advance the destination pointer by a row (source pointer remains in the same place) */
dst += dst_stride * sizeof(uint16_t);
@@ -333,7 +352,7 @@ static void av_always_inline dng_blit(TiffContext *s, uint8_t *dst, int dst_stri
/* Blit second half of input row row to next row of output */
for (col = 0; col < width; col++)
- *dst_u16++ = dng_process_color16(*src_u16++, s->dng_lut, s->black_level, scale_factor);
+ *dst_u16++ = dng_process_color16(*src_u16++, s->dng_lut, s->black_level, scale_factor[(col&1) + 2]);
dst += dst_stride * sizeof(uint16_t);
src += src_stride * sizeof(uint16_t);
@@ -347,7 +366,7 @@ static void av_always_inline dng_blit(TiffContext *s, uint8_t *dst, int dst_stri
uint16_t *src_u16 = (uint16_t *)src;
for (col = 0; col < width; col++)
- *dst_u16++ = dng_process_color16(*src_u16++, s->dng_lut, s->black_level, scale_factor);
+ *dst_u16++ = dng_process_color16(*src_u16++, s->dng_lut, s->black_level, scale_factor[(col&1) + 2 * ((line&1) + odd_line)]);
dst += dst_stride * sizeof(uint16_t);
src += src_stride * sizeof(uint16_t);
@@ -358,7 +377,7 @@ static void av_always_inline dng_blit(TiffContext *s, uint8_t *dst, int dst_stri
const uint8_t *src_u8 = src;
for (col = 0; col < width; col++)
- *dst_u8++ = dng_process_color8(*src_u8++, s->dng_lut, s->black_level, scale_factor);
+ *dst_u8++ = dng_process_color8(*src_u8++, s->dng_lut, s->black_level, scale_factor[(col&1) + 2 * ((line&1) + odd_line)]);
dst += dst_stride;
src += src_stride;
@@ -712,7 +731,7 @@ static int dng_decode_jpeg(AVCodecContext *avctx, AVFrame *frame,
w,
h,
is_single_comp,
- is_u16);
+ is_u16, 0);
av_frame_unref(s->jpgframe);
@@ -892,7 +911,8 @@ static int tiff_unpack_strip(TiffContext *s, AVFrame *p, uint8_t *dst, int strid
elements,
1,
0, // single-component variation is only preset in JPEG-encoded DNGs
- is_u16);
+ is_u16,
+ (line + strip_start)&1);
}
src += width;
@@ -1431,6 +1451,7 @@ static int tiff_decode_tag(TiffContext *s, AVFrame *frame)
return AVERROR_INVALIDDATA;
for (int i = 0; i < count; i++)
s->dng_lut[i] = ff_tget(&s->gb, type, s->le);
+ s->white_level = s->dng_lut[count-1];
break;
case DNG_BLACK_LEVEL:
if (count > 1) { /* Use the first value in the pattern (assume they're all the same) */
@@ -1728,6 +1749,84 @@ static int tiff_decode_tag(TiffContext *s, AVFrame *frame)
tiff_set_type(s, TIFF_TYPE_DNG);
}
break;
+ case DNG_ANALOG_BALANCE:
+ if (type != TIFF_RATIONAL)
+ break;
+
+ for (int i = 0; i < 3; i++) {
+ value = ff_tget(&s->gb, TIFF_LONG, s->le);
+ value2 = ff_tget(&s->gb, TIFF_LONG, s->le);
+ if (!value2) {
+ av_log(s->avctx, AV_LOG_WARNING, "Invalid denominator\n");
+ value2 = 1;
+ }
+
+ s->analog_balance[i] = value / (float)value2;
+ }
+ break;
+ case DNG_AS_SHOT_NEUTRAL:
+ if (type != TIFF_RATIONAL)
+ break;
+
+ for (int i = 0; i < 3; i++) {
+ value = ff_tget(&s->gb, TIFF_LONG, s->le);
+ value2 = ff_tget(&s->gb, TIFF_LONG, s->le);
+ if (!value2) {
+ av_log(s->avctx, AV_LOG_WARNING, "Invalid denominator\n");
+ value2 = 1;
+ }
+
+ s->as_shot_neutral[i] = value / (float)value2;
+ }
+ break;
+ case DNG_AS_SHOT_WHITE_XY:
+ if (type != TIFF_RATIONAL)
+ break;
+
+ for (int i = 0; i < 2; i++) {
+ value = ff_tget(&s->gb, TIFF_LONG, s->le);
+ value2 = ff_tget(&s->gb, TIFF_LONG, s->le);
+ if (!value2) {
+ av_log(s->avctx, AV_LOG_WARNING, "Invalid denominator\n");
+ value2 = 1;
+ }
+
+ s->as_shot_white[i] = value / (float)value2;
+ }
+ s->as_shot_white[2] = 1.f - s->as_shot_white[0] - s->as_shot_white[1];
+ for (int i = 0; i < 3; i++) {
+ s->as_shot_white[i] /= d65_white[i];
+ }
+ break;
+ case DNG_COLOR_MATRIX1:
+ case DNG_COLOR_MATRIX2:
+ for (int i = 0; i < 3; i++) {
+ for (int j = 0; j < 3; j++) {
+ int value = ff_tget(&s->gb, TIFF_LONG, s->le);
+ int value2 = ff_tget(&s->gb, TIFF_LONG, s->le);
+ if (!value2) {
+ av_log(s->avctx, AV_LOG_WARNING, "Invalid denominator\n");
+ value2 = 1;
+ }
+ s->color_matrix[i][j] = value / (float)value2;
+ }
+ s->use_color_matrix = 1;
+ }
+ break;
+ case DNG_CAMERA_CALIBRATION1:
+ case DNG_CAMERA_CALIBRATION2:
+ for (int i = 0; i < 3; i++) {
+ for (int j = 0; j < 3; j++) {
+ int value = ff_tget(&s->gb, TIFF_LONG, s->le);
+ int value2 = ff_tget(&s->gb, TIFF_LONG, s->le);
+ if (!value2) {
+ av_log(s->avctx, AV_LOG_WARNING, "Invalid denominator\n");
+ value2 = 1;
+ }
+ s->camera_calibration[i][j] = value / (float)value2;
+ }
+ }
+ break;
case CINEMADNG_TIME_CODES:
case CINEMADNG_FRAME_RATE:
case CINEMADNG_T_STOP:
@@ -1755,6 +1854,41 @@ end:
return 0;
}
+static const float xyz2rgb[3][3] = {
+ { 0.412453f, 0.357580f, 0.180423f },
+ { 0.212671f, 0.715160f, 0.072169f },
+ { 0.019334f, 0.119193f, 0.950227f },
+};
+
+static void camera_xyz_coeff(TiffContext *s,
+ float rgb2cam[3][4],
+ double cam2xyz[4][3])
+{
+ double cam2rgb[4][3], inverse[4][3], num;
+ int i, j, k;
+
+ for (i = 0; i < 3; i++) {
+ for (j = 0; j < 3; j++) {
+ cam2rgb[i][j] = 0.;
+ for (k = 0; k < 3; k++)
+ cam2rgb[i][j] += cam2xyz[i][k] * xyz2rgb[k][j];
+ }
+ }
+
+ for (i = 0; i < 3; i++) {
+ for (num = j = 0; j < 3; j++)
+ num += cam2rgb[i][j];
+ for (j = 0; j < 3; j++)
+ cam2rgb[i][j] /= num;
+ s->premultiply[i] = 1.f / num;
+ }
+
+// pseudoinverse(cam2rgb, inverse, colors);
+// for (i = 0; i < 3; i++)
+// for (j = 0; j < 3; j++)
+// rgb2cam[i][j] = inverse[j][i];
+}
+
static int decode_frame(AVCodecContext *avctx, AVFrame *p,
int *got_frame, AVPacket *avpkt)
{
@@ -1784,6 +1918,7 @@ static int decode_frame(AVCodecContext *avctx, AVFrame *p,
// TIFF_BPP is not a required tag and defaults to 1
s->tiff_type = TIFF_TYPE_TIFF;
+ s->use_color_matrix = 0;
again:
s->is_thumbnail = 0;
s->bppcount = s->bpp = 1;
@@ -1800,6 +1935,22 @@ again:
for (i = 0; i < 65536; i++)
s->dng_lut[i] = i;
+ for (i = 0; i < FF_ARRAY_ELEMS(s->as_shot_neutral); i++)
+ s->as_shot_neutral[i] = 0.f;
+
+ for (i = 0; i < FF_ARRAY_ELEMS(s->as_shot_white); i++)
+ s->as_shot_white[i] = 1.f;
+
+ for (i = 0; i < FF_ARRAY_ELEMS(s->analog_balance); i++)
+ s->analog_balance[i] = 1.f;
+
+ for (i = 0; i < FF_ARRAY_ELEMS(s->premultiply); i++)
+ s->premultiply[i] = 1.f;
+
+ for (i = 0; i < 4; i++)
+ for (j = 0; j < 4; j++)
+ s->camera_calibration[i][j] = i == j;
+
free_geotags(s);
// Reset these offsets so we can tell if they were set this frame
@@ -1872,8 +2023,37 @@ again:
}
if (is_dng) {
+ double cam2xyz[4][3];
+ float cmatrix[3][4];
+ float pmin = FLT_MAX;
int bps;
+ for (i = 0; i < 3; i++) {
+ for (j = 0; j < 3; j++)
+ s->camera_calibration[i][j] *= s->analog_balance[i];
+ }
+
+ if (!s->use_color_matrix) {
+ for (i = 0; i < 3; i++)
+ s->premultiply[i] /= s->camera_calibration[i][i];
+ } else {
+ for (int c = 0; c < 3; c++) {
+ for (i = 0; i < 3; i++) {
+ cam2xyz[c][i] = 0.;
+ for (j = 0; j < 3; j++)
+ cam2xyz[c][i] += s->camera_calibration[c][j] * s->color_matrix[j][i] * s->as_shot_white[i];
+ }
+ }
+
+ camera_xyz_coeff(s, cmatrix, cam2xyz);
+ }
+
+ for (int c = 0; c < 3; c++)
+ pmin = fminf(pmin, s->premultiply[c]);
+
+ for (int c = 0; c < 3; c++)
+ s->premultiply[c] /= pmin;
+
if (s->bpp % s->bppcount)
return AVERROR_INVALIDDATA;
bps = s->bpp / s->bppcount;
diff --git a/libavcodec/tiff.h b/libavcodec/tiff.h
index 9d2ab90f52..e67c59abad 100644
--- a/libavcodec/tiff.h
+++ b/libavcodec/tiff.h
@@ -106,6 +106,13 @@ enum DngTags {
DNG_LINEARIZATION_TABLE = 0xC618,
DNG_BLACK_LEVEL = 0xC61A,
DNG_WHITE_LEVEL = 0xC61D,
+ DNG_COLOR_MATRIX1 = 0xC621,
+ DNG_COLOR_MATRIX2 = 0xC622,
+ DNG_CAMERA_CALIBRATION1 = 0xC623,
+ DNG_CAMERA_CALIBRATION2 = 0xC624,
+ DNG_ANALOG_BALANCE = 0xC627,
+ DNG_AS_SHOT_NEUTRAL = 0xC628,
+ DNG_AS_SHOT_WHITE_XY = 0xC629,
};
/** list of CinemaDNG tags */
More information about the ffmpeg-cvslog
mailing list