1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
|
#ifndef XIM_H_INCLUDED
#define XIM_H_INCLUDED
/* xim.h - header file for Xim files
**
** Taken from the X.V11R4 version of XimHeader.h:
**
** Author: Philip R. Thompson
** Address: phils@athena.mit.edu, 9-526
** Note: size of header should be 1024 (1K) bytes.
** $Header: /mit/phils/X/RCS/XimHeader.h,v 1.7 89/11/09 17:26:54 phils Exp Locker: phils $
** $Date: 89/11/09 17:26:54 $
** $Source: /mit/phils/X/RCS/XimHeader.h,v $
*/
#define IMAGE_VERSION 3
#ifndef _BYTE
typedef unsigned char byte;
#define _BYTE 1
#endif
/* External ascii file format. */
typedef struct ImageHeader {
char file_version[8]; /* header version */
char header_size[8]; /* Size of file header in bytes */
char image_width[8]; /* Width of the raster image */
char image_height[8]; /* Height of the raster image */
char num_colors[8]; /* Actual number of entries in c_map */
char num_channels[3]; /* 0 or 1 = pixmap, 3 = RG&B buffers */
char bytes_per_line[5]; /* bytes per scanline */
char num_pictures[4]; /* Number of pictures in file */
char bits_per_channel[4]; /* usually 1 or 8 */
char alpha_channel[4]; /* Alpha channel flag */
char runlength[4]; /* Runlength encoded flag */
char author[48]; /* Name of who made it */
char date[32]; /* Date and time image was made */
char program[16]; /* Program that created this file */
char comment[96]; /* other viewing info. for this image */
unsigned char c_map[256][3]; /* RGB values of the pixmap indices */
} ImageHeader, XimAsciiHeader;
/* Internal binary format. */
typedef struct Color {
byte pixel, red, grn, blu;
} Color;
typedef struct XimImage {
int width; /* width of the image in pixels */
int height; /* height of the image in pixels */
unsigned datasize; /* size of one channel of data */
short nchannels; /* number data channels in image */
short bits_channel; /* usually 1 or 8 */
short bytes_per_line; /* bytes to hold one scanline */
byte* data; /* pixmap or red channel data */
byte* grn_data; /* green channel data */
byte* blu_data; /* blue channel data */
byte* other; /* other (alpha) data */
unsigned alpha_flag :1; /* alpha channel flag */
unsigned packed_flag:1; /* data packed in one chunk of memory */
unsigned runlen_flag:1; /* runlength encoded data flag */
unsigned : 0; /* future flags, word alignment */
short tpics, npics; /* number of images, total & left in file */
short ncolors; /* " " colors in the color table */
Color* colors; /* colortable, one byte per r/g/b & pixel */
char* author; /* author credit, copyright, etc */
char* date; /* date image was made, grabbed, etc. */
char* program; /* program used to make this */
short ncomments; /* number of comments strings */
char** comments; /* pointers to null terminated strings */
char* offset; /* original offset in machine memory */
float chroma_red[2]; /* x, y image chromacity coords */
float chroma_grn[2];
float chroma_blu[2];
float chroma_wht[2];
float gamma; /* image storage gamma */
} XimImage;
/* Future external ascii variable length header - under review. */
#if (IMAGE_VERSION == 4)
typedef struct XimAsciiHeader {
char file_version[4]; /* header version */
char header_size[8]; /* Size of file header (fixed part only) */
char image_height[8]; /* Height of the raster image in pixels */
char image_width[8]; /* Width of the raster image in pixels */
char bytes_line[8]; /* Actual # of bytes separating scanlines */
char bits_channel[4]; /* Bits per channel (usually 1 or 8) */
char num_channels[4]; /* 1 = pixmap, 3 = RG&B buffers */
char alpha_channel[2]; /* Alpha channel flag */
char num_colors[4]; /* Number of entries in c_map (if any) */
char num_pictures[4]; /* Number of images in file */
char runlength_flag[2]; /* Runlength encoded flag */
char future_flags[8];
char author[48]; /* Name of who made it, from passwd entry */
char date[32]; /* Unix format date */
char program[32]; /* Program that created this */
char gamma[12]; /* image storage gamma */
char chroma_red[24]; /* image red primary chromaticity coords. */
char chroma_grn[24]; /* " green " " " */
char chroma_blu[24]; /* " blue " " " */
char chroma_wht[24]; /* " white point " " */
char comment_length[8] /* Total length of comments */
/* char* comment; Null separated comments */
/* unsigned char c_map[]; RGB Colortable, (ncolors * 3 bytes) */
} XimAsciiHeader;
#endif /*IMAGE_VERSION 4*/
#ifndef rnd
#define rnd(x) ((int)((float)(x) + 0.5)) /* round a float to an int */
#endif
/* Note:
* - All data is in char's in order to maintain easily portability
* across machines, and some human readability.
* - Images may be stored as pixmaps (8 bits/pixel) or as separate
* red, green, blue channel data (24+ bits/pixel).
* - An alpha channel is optional and is found after every num_channels
* of data.
* - Pixmaps or RGB (and alpha) channel data are stored respectively
* after the header.
* - If num_channels = 1, a pixmap is assumed and the colormap in the
* header is used.
* - Data size = image_width * image_height.
*/
#endif
|
