commit d1a5dfdf162d1e1200e7ee1060435d76a028d4c4
parent 34d326d46d31332fa2182793475672617933a939
Author: Mattias Andrée <maandree@kth.se>
Date: Fri, 7 Jul 2017 20:58:16 +0200
Add blind-chroma-key
Signed-off-by: Mattias Andrée <maandree@kth.se>
Diffstat:
8 files changed, 146 insertions(+), 8 deletions(-)
diff --git a/Makefile b/Makefile
@@ -5,6 +5,7 @@ BIN =\
blind-arithm\
blind-cat-cols\
blind-cat-rows\
+ blind-chroma-key\
blind-colour-ciexyz\
blind-colour-srgb\
blind-compress\
diff --git a/README b/README
@@ -21,6 +21,9 @@ UTILITIES
blind-cat-rows(1)
Stack videos vertically
+ blind-chroma-key(1)
+ Replace a colour range with transparency
+
blind-colour-ciexyz(1)
Convert CIE XYZ for use with blind-single-colour(1)
diff --git a/TODO b/TODO
@@ -1,8 +1,6 @@
blind-transform affine transformation by matrix multiplication, -t for tiling, -s for
improve quality on downscaling (pixels' neighbours must not change).
-blind-chroma-key replace a chroma with transparency or create an mask for the alpha channel.
-blind-primary-key replace a primary with transparency or create an mask for the alpha channel,
- -g for greyscaled images.
+blind-primary-key replace a primary with transparency, -g for greyscaled images.
blind-primaries given three selectable primaries split the video into three side-by-side which
only one primary active.
blind-apply-map remap pixels (distortion) using the X and Y values, -t for tiling, -s for
diff --git a/man/blind-chroma-key.1 b/man/blind-chroma-key.1
@@ -0,0 +1,39 @@
+.TH BLIND-CHROMA-KEY 1 blind
+.SH NAME
+blind-chroma-key - Replace a colour range with transparency
+.SH SYNOPSIS
+.B blind-chroma-key
+.I key-stream
+.SH DESCRIPTION
+.B blind-chroma-key
+reads a video from stdin and colours from
+.IR key-stream .
+Each frame in
+.I key-stream
+should contain exactly two pixels. The colour of
+the first pixel, and all colours with a distance
+from that colour upto the same distance the colour
+of the second pixel has to that colour, will be
+turned into transparency in the video from stdin,
+and the resulting video will be printed to stdout.
+.P
+If the two colours in a frame from
+.I key-stream
+have the same alpha value, all matching colours
+will be turned into full transparency. Otherwise,
+the colours matching the first colour will be
+given the transparency specified with the first
+colour, all other matching colours will have
+a transparency between to two specified alpha
+values. However, if alpha value of the second
+colour is less than the alpha value of the first
+colour, twos alpha values are inverted.
+.SH SEE ALSO
+.BR blind (7),
+.BR blind-from-text (1),
+.BR blind-colour-ciexyz (1),
+.BR blind-colour-srgb (1),
+.BR blind-dual-key (1)
+.SH AUTHORS
+Mattias Andrée
+.RI < maandree@kth.se >
diff --git a/man/blind-dual-key.1 b/man/blind-dual-key.1
@@ -9,11 +9,11 @@ blind-dual-key - Apply transparency to a video based on two videos and two key
.I dual-X
.I dual-Y
.I dual-Z
-.I dual-video
+.I dual-stream
.SH DESCRIPTION
.B blind-dual-key
reads a video from stdin and a video
-.IR dual-video .
+.IR dual-stream .
These two videos should be idential, except
with two different background colours. The
background colour used in the video from
@@ -24,7 +24,7 @@ and
.IR Z ,
using the CIE XYZ colour model. The
background colour used in the video from
-.I dual-video
+.I dual-stream
should be specified in the arguments
.IR dual-X ,
.IR dual-Y ,
@@ -49,7 +49,8 @@ example black and white or green and magenta.
.SH SEE ALSO
.BR blind (7),
.BR blind-colour-ciexyz (1),
-.BR blind-colour-srgb (1)
+.BR blind-colour-srgb (1),
+.BR blind-chroma-key (1)
.SH AUTHORS
Mattias Andrée
.RI < maandree@kth.se >
diff --git a/man/blind.7 b/man/blind.7
@@ -28,6 +28,9 @@ Place videos side by side
.BR blind-cat-rows (1)
Stack videos vertically
.TP
+.BR blind-chroma-key(1)
+Replace a colour range with transparency
+.TP
.BR blind-colour-ciexyz (1)
Convert CIE XYZ for use with
.BR blind-single-colour (1)
diff --git a/src/blind-chroma-key.c b/src/blind-chroma-key.c
@@ -0,0 +1,92 @@
+/* See LICENSE file for copyright and license details. */
+#include "common.h"
+
+USAGE("key-stream")
+
+
+#define PROCESS(TYPE, SUFFIX)\
+ static void\
+ process_##SUFFIX(struct stream *stream, struct stream *key)\
+ {\
+ size_t i, n, m = 0;\
+ TYPE x1, y1, z1, a1, a2, variance2, *keyxyza;\
+ TYPE x, y, z, d;\
+ do {\
+ if (!m) {\
+ m = stream->frame_size;\
+ while (key->ptr < key->frame_size)\
+ if (!eread_stream(key, key->frame_size - key->ptr))\
+ return;\
+ keyxyza = (TYPE *)(key->buf);\
+ x1 = keyxyza[0];\
+ y1 = keyxyza[1];\
+ z1 = keyxyza[2];\
+ a1 = keyxyza[3];\
+ x = x1 - keyxyza[4];\
+ y = y1 - keyxyza[5];\
+ z = z1 - keyxyza[6];\
+ a2 = keyxyza[7];\
+ variance2 = x * x + y * y + z * z;\
+ if (a2 > a1) {\
+ a1 = 1 - a1;\
+ a2 = 1 - a2;\
+ }\
+ memmove(key->buf, key->buf + key->frame_size,\
+ key->ptr -= key->frame_size);\
+ }\
+ n = MIN(stream->ptr, m) / stream->pixel_size;\
+ for (i = 0; i < n; i++) {\
+ x = ((TYPE *)(stream->buf))[4 * i + 0] - x1;\
+ y = ((TYPE *)(stream->buf))[4 * i + 1] - y1;\
+ z = ((TYPE *)(stream->buf))[4 * i + 2] - z1;\
+ d = x * x + y * y + z * z;\
+ if (d <= variance2) {\
+ if (a1 == a2)\
+ d = 0;\
+ else\
+ d = sqrt(d / variance2) * (a1 - a2) + a2;\
+ ((TYPE *)(stream->buf))[4 * i + 3] *= d;\
+ }\
+ }\
+ n *= stream->pixel_size;\
+ m -= n;\
+ ewriteall(STDOUT_FILENO, stream->buf, n, "<stdout>");\
+ memmove(stream->buf, stream->buf + n, stream->ptr -= n);\
+ } while (eread_stream(stream, SIZE_MAX));\
+ if (stream->ptr)\
+ eprintf("%s: incomplete frame\n", stream->file);\
+ }
+
+PROCESS(double, lf)
+PROCESS(float, f)
+
+
+int
+main(int argc, char *argv[])
+{
+ struct stream stream, key;
+ void (*process)(struct stream *stream, struct stream *key);
+
+ UNOFLAGS(argc != 1);
+
+ eopen_stream(&stream, NULL);
+ eopen_stream(&key, argv[0]);
+
+ if (!strcmp(stream.pixfmt, "xyza"))
+ process = process_lf;
+ else if (!strcmp(stream.pixfmt, "xyza f"))
+ process = process_f;
+ else
+ eprintf("pixel format %s is not supported, try xyza\n", stream.pixfmt);
+
+ if (strcmp(stream.pixfmt, key.pixfmt))
+ eprintf("videos use incompatible pixel formats\n");
+
+ if (key.width > 2 || key.height > 2 || key.width * key.height != 2)
+ eprintf("%s: each frame must contain exactly 2 pixels\n", key.file);
+
+ fprint_stream_head(stdout, &stream);
+ efflush(stdout, "<stdout>");
+ process(&stream, &key);
+ return 0;
+}
diff --git a/src/blind-sinc-wave.c b/src/blind-sinc-wave.c
@@ -16,7 +16,6 @@ static int equal = 0;
TYPE y, theta0y = 0;\
TYPE z, theta0z = 0;\
TYPE a, theta0a = 0;\
- echeck_dimensions(grad, WIDTH | HEIGHT, NULL);\
do {\
if (!m) {\
m = grad->frame_size;\
@@ -107,6 +106,8 @@ main(int argc, char *argv[])
if (have_theta0 && strcmp(stream.pixfmt, theta0.pixfmt))
eprintf("videos use incompatible pixel formats\n");
+ echeck_dimensions(&stream, WIDTH | HEIGHT, NULL);
+
fprint_stream_head(stdout, &stream);
efflush(stdout, "<stdout>");
process(&stream, have_theta0 ? &theta0 : NULL);
