farbfeld.5 - farbfeld - suckless image format with conversion tools
(HTM) git clone git://git.suckless.org/farbfeld
(DIR) Log
(DIR) Files
(DIR) Refs
(DIR) README
(DIR) LICENSE
---
farbfeld.5 (4301B)
---
1 .Dd 2018-04-11
2 .Dt FARBFELD 5
3 .Os suckless.org
4 .Sh NAME
5 .Nm farbfeld
6 .Nd suckless image format
7 .Sh DESCRIPTION
8 .Nm
9 is a
10 .Em lossless
11 image format which is easy to parse, pipe and compress.
12 It has the following format:
13 .Bd -literal -offset left
14 BYTES DESCRIPTION
15 8 "farbfeld" magic value
16 4 32-Bit BE unsigned integer (width)
17 4 32-Bit BE unsigned integer (height)
18 [2222] 4*16-Bit BE unsigned integers [RGBA] / pixel, row-major
19 .Ed
20 .Pp
21 The RGB-data should be sRGB for best interoperability and not
22 alpha-premultiplied.
23 .Sh USAGE
24 .Nm
25 provides the tools
26 .Xr 2ff 1 ,
27 .Xr jpg2ff 1 ,
28 .Xr png2ff 1
29 and
30 .Xr ff2jpg 1 ,
31 .Xr ff2pam 1 ,
32 .Xr ff2png 1 ,
33 .Xr ff2ppm 1
34 to
35 .Em convert
36 to and from farbfeld images respectively.
37 .Pp
38 .Xr bzip2 1
39 is recommended for
40 .Em compression ,
41 giving results comparable with PNG for photographs and much better results
42 for other image types.
43 .sp
44 The
45 .Em file extension
46 is ".ff" and compression extensions shall be
47 appended (e.g. ".ff.bz2").
48 .Sh MOTIVATION
49 .Nm
50 was created because the author was not satisfied with the boilerplate
51 and inherent complexity involved in handling common image formats
52 (PNG, JPEG, GIF,...), having to rely on bloated libraries while not being
53 able to focus on the task at hand for a given image processing problem.
54 .Sh EXAMPLES
55 The following code listing
56 .Em invert.c
57 is a ready-to-use color inverter with all necessary error handling and
58 reporting. This program can be integrated into a farbfeld pipeline as
59 follows:
60 .Pp
61 $ png2ff < image.png | invert | ff2png > image-inverted.png
62 .Pp
63 It shall be noted here that due to the simplicity of the format no
64 external libraries are needed to handle the farbfeld image data. The
65 0BSD-License gives you the freedom to throw away the license block and
66 just use the code as you wish. Happy hacking!
67 .Bd -literal -offset left
68 /*
69 * 0BSD-License
70 *
71 * (c) 2017 Laslo Hunhold <dev@frign.de>
72 *
73 * Permission to use, copy, modify, and/or distribute this software for
74 * any purpose with or without fee is hereby granted.
75 *
76 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL
77 * WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED
78 * WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE
79 * AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
80 * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
81 * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
82 * TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
83 * PERFORMANCE OF THIS SOFTWARE.
84 */
85 #include <arpa/inet.h>
86
87 #include <errno.h>
88 #include <stdint.h>
89 #include <stdio.h>
90 #include <string.h>
91
92 #define LEN(x) (sizeof (x) / sizeof *(x))
93
94 static void
95 invert(uint16_t rgba[4])
96 {
97 rgba[0] = UINT16_MAX - rgba[0];
98 rgba[1] = UINT16_MAX - rgba[1];
99 rgba[2] = UINT16_MAX - rgba[2];
100 }
101
102 int
103 main(int argc, char *argv[])
104 {
105 uint32_t hdr[4], width, height, i, j, k;
106 uint16_t rgba[4];
107
108 /* arguments */
109 if (argc != 1) {
110 fprintf(stderr, "usage: %s\\n", argv[0]);
111 return 1;
112 }
113
114 /* read header */
115 if (fread(hdr, sizeof(*hdr), LEN(hdr), stdin) != LEN(hdr)) {
116 goto readerr;
117 }
118 if (memcmp("farbfeld", hdr, sizeof("farbfeld") - 1)) {
119 fprintf(stderr, "%s: invalid magic value\\n", argv[0]);
120 return 1;
121 }
122 width = ntohl(hdr[2]);
123 height = ntohl(hdr[3]);
124
125 /* write data */
126 if (fwrite(hdr, sizeof(*hdr), LEN(hdr), stdout) != 4) {
127 goto writerr;
128 }
129
130 for (i = 0; i < height; i++) {
131 for (j = 0; j < width; j++) {
132 if (fread(rgba, sizeof(*rgba), LEN(rgba),
133 stdin) != LEN(rgba)) {
134 goto readerr;
135 }
136 for (k = 0; k < 4; k++) {
137 rgba[k] = ntohs(rgba[k]);
138 }
139
140 invert(rgba);
141
142 for (k = 0; k < 4; k++) {
143 rgba[k] = htons(rgba[k]);
144 }
145 if (fwrite(rgba, sizeof(*rgba), LEN(rgba),
146 stdout) != LEN(rgba)) {
147 goto writerr;
148 }
149 }
150 }
151
152 /* clean up */
153 if (fclose(stdout)) {
154 fprintf(stderr, "%s: fclose: %s\\n", argv[0],
155 strerror(errno));
156 return 1;
157 }
158
159 return 0;
160 readerr:
161 fprintf(stderr, "%s: fread: Unexpected EOF\\n", argv[0]);
162 return 1;
163 writerr:
164 fprintf(stderr, "%s: fwrite: %s\\n", argv[0], strerror(errno));
165 return 1;
166 }
167 .Ed
168 .Sh SEE ALSO
169 .Xr 2ff 1 ,
170 .Xr ff2jpg 1 ,
171 .Xr ff2pam 1 ,
172 .Xr ff2png 1 ,
173 .Xr ff2ppm 1 ,
174 .Xr jpg2ff 1 ,
175 .Xr png2ff 1
176 .Sh AUTHORS
177 .An Laslo Hunhold Aq Mt dev@frign.de