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
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
|
#ifdef _WIN32
#include <windows.h>
#endif
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <jpeglib.h>
#include <jerror.h>
#include <png.h>
#include "gr.h"
static int read_jpeg_image(char *path, int *width, int *height, int **data)
{
FILE *stream;
unsigned int i;
struct jpeg_decompress_struct cinfo;
struct jpeg_error_mgr jerr;
JSAMPARRAY buffer;
int row_stride, bpix;
unsigned int r, g, b, a;
int *dataP;
if ((stream = fopen(path, "rb")) != NULL)
{
cinfo.err = jpeg_std_error(&jerr);
jpeg_create_decompress(&cinfo);
jpeg_stdio_src(&cinfo, stream);
jpeg_read_header(&cinfo, TRUE);
jpeg_start_decompress(&cinfo);
*width = cinfo.output_width;
*height = cinfo.output_height;
*data = dataP = (int *)malloc(cinfo.output_width * cinfo.output_height * sizeof(int));
row_stride = cinfo.output_width * cinfo.output_components;
buffer = (*cinfo.mem->alloc_sarray)((j_common_ptr)&cinfo, JPOOL_IMAGE, row_stride, 1);
bpix = cinfo.output_components;
while (cinfo.output_scanline < cinfo.output_height)
{
jpeg_read_scanlines(&cinfo, buffer, 1);
for (i = 0; i < bpix * cinfo.output_width; i += bpix)
{
r = buffer[0][i];
g = buffer[0][i + 1] << 8;
b = buffer[0][i + 2] << 16;
if (bpix == 4)
a = buffer[0][i + 3] << 24;
else
a = 255 << 24;
*dataP++ = r | g | b | a;
}
}
jpeg_finish_decompress(&cinfo);
jpeg_destroy_decompress(&cinfo);
fclose(stream);
return 0;
}
else
return -1;
}
#define PNG_BYTES_TO_CHECK 4
static int read_png_image(char *path, int *width, int *height, int **data)
{
static FILE *stream;
unsigned char header[PNG_BYTES_TO_CHECK];
png_structp png_ptr;
png_infop info_ptr;
png_bytep *row_pointers;
int x, y, channels, color_type;
unsigned int r, g, b, a;
int *dataP;
volatile int ret = -1;
size_t nbytes;
if ((stream = fopen(path, "rb")) != NULL)
{
nbytes = fread(header, 1, PNG_BYTES_TO_CHECK, stream);
if (nbytes > 0 && !png_sig_cmp(header, 0, PNG_BYTES_TO_CHECK))
{
png_ptr = png_create_read_struct(PNG_LIBPNG_VER_STRING, NULL, NULL, NULL);
if (png_ptr)
{
info_ptr = png_create_info_struct(png_ptr);
if (info_ptr)
{
if (setjmp(png_jmpbuf(png_ptr)))
{
png_destroy_read_struct(&png_ptr, &info_ptr, NULL);
fclose(stream);
return -1;
}
png_init_io(png_ptr, stream);
png_set_sig_bytes(png_ptr, PNG_BYTES_TO_CHECK);
png_read_info(png_ptr, info_ptr);
color_type = png_get_color_type(png_ptr, info_ptr);
if (color_type == PNG_COLOR_TYPE_PALETTE) png_set_palette_to_rgb(png_ptr);
if (color_type == PNG_COLOR_TYPE_GRAY)
channels = 1;
else if (color_type == PNG_COLOR_TYPE_RGBA)
channels = 4;
else
channels = 3;
if (png_get_valid(png_ptr, info_ptr, PNG_INFO_tRNS))
{
png_set_tRNS_to_alpha(png_ptr);
channels += 1;
}
if (color_type == PNG_COLOR_TYPE_GRAY || color_type == PNG_COLOR_TYPE_PALETTE ||
color_type == PNG_COLOR_TYPE_RGB || color_type == PNG_COLOR_TYPE_RGBA)
{
*width = png_get_image_width(png_ptr, info_ptr);
*height = png_get_image_height(png_ptr, info_ptr);
*data = dataP = (int *)malloc(*width * *height * sizeof(int));
(void)png_set_interlace_handling(png_ptr);
png_read_update_info(png_ptr, info_ptr);
row_pointers = (png_bytep *)malloc(sizeof(png_bytep) * *height);
for (y = 0; y < *height; y++)
row_pointers[y] = (png_byte *)malloc(png_get_rowbytes(png_ptr, info_ptr));
png_read_image(png_ptr, row_pointers);
for (y = 0; y < *height; y++)
{
png_byte *row = row_pointers[y];
for (x = 0; x < *width; x++)
{
png_byte *ptr = &(row[x * channels]);
if (channels == 1)
r = g = b = ptr[0];
else
{
r = ptr[0];
g = ptr[1];
b = ptr[2];
}
if (channels > 3)
a = ptr[3];
else
a = 255;
*dataP++ = r | (g << 8) | (b << 16) | (a << 24);
}
}
for (y = 0; y < *height; y++) free(row_pointers[y]);
free(row_pointers);
ret = 0;
}
else
fprintf(stderr, "unsupported PNG color type\n");
}
else
fprintf(stderr, "PNG information structure allocation error\n");
png_destroy_read_struct(&png_ptr, NULL, NULL);
}
else
fprintf(stderr, "PNG structure allocation error\n");
}
else
fprintf(stderr, "file %s is not recognized as a PNG file\n", path);
fclose(stream);
}
else
fprintf(stderr, "file %s could not be opened for reading\n", path);
return ret;
}
int gr_readimage(char *path, int *width, int *height, int **data)
{
FILE *stream;
char header[10];
int ret = -1;
size_t nbytes;
if ((stream = fopen(path, "rb")) != NULL)
{
nbytes = fread(header, 1, 10, stream);
fclose(stream);
if (nbytes > 0)
{
if (!strncmp(header, "\211PNG\r\n\032\n", 8))
{
ret = read_png_image(path, width, height, data);
}
else if ((!strncmp(header, "\377\330\377\340", 4) || !strncmp(header, "\377\330\377\356", 4)) &&
!strncmp(header + 6, "JFIF", 4))
{
ret = read_jpeg_image(path, width, height, data);
}
else
ret = -1;
}
else
ret = -1;
}
return ret;
}
|
