-
Notifications
You must be signed in to change notification settings - Fork 0
/
utils.c
128 lines (113 loc) · 2.39 KB
/
utils.c
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
#include "utils.h"
//check for a valid header
int Is_BMPHeader_Valid(BMPHeader* header, FILE *fptr) {
if (header -> type != 0x4D42)
{
return FALSE;
}
if (header -> offset != BMP_HEADER_SIZE)
{
return FALSE;
}
if ((header -> bits) != 24)
{
return FALSE;
}
if ((header -> planes) != 1)
{
return FALSE;
}
if ((header -> compression) != 0)
{
return FALSE;
}
if ((header -> DIB_header_size) != DIB_HEADER_SIZE)
{
return FALSE;
}
if ((header->ncolours) != 0)
{
return FALSE;
}
if ((header->importantcolours) != 0)
{
return FALSE;
}
if ((header->imagesize) != (header->width)*(header->height)*(header->bits)/8)
{
return FALSE;
}
if ((header->size) != 54 + (header->width)*(header->height)*(header->bits)/8)
{
return FALSE;
}
return TRUE;
}
BMPImage *BMP_Open(const char *filename) {
FILE *fptr = fopen(filename,"r");
BMPImage *bmpImage = (BMPImage *)malloc(sizeof(BMPImage));
//check for memory allocation errors
if (bmpImage == NULL)
{
fprintf(stderr, "Error allocating memory\n");
free(bmpImage);
return NULL;
}
if (fptr == NULL)
{
fprintf(stderr, "Error opening file\n");
return NULL;
}
//Read the first 54 bytes of the source into the header
fseek(fptr, 0, SEEK_SET);
fread(&(bmpImage->header), sizeof(BMPHeader), 1, fptr);
//check if the header is valid
if (Is_BMPHeader_Valid(&(bmpImage->header), fptr) == 0)
{
return NULL;
}
// Allocate memory for image data
bmpImage->data = (unsigned char *)malloc(sizeof(unsigned char)*((int)((bmpImage->header).imagesize)));
//check error
if (bmpImage->data == NULL)
{
fprintf(stderr, "Error allocating memory\n");
free(bmpImage);
return NULL;
}
fseek(fptr, (bmpImage->header).offset , SEEK_SET);
if (fread(bmpImage->data, sizeof(unsigned char)*(int)(bmpImage->header).imagesize, 1, fptr) != 1)
{
return NULL;
}
fclose(fptr);
return bmpImage;
}
int BMP_Write(const char * outfile, BMPImage* image){
FILE *fptr = fopen(outfile, "w");
//open file and check for error
if (fptr == NULL)
{
fclose(fptr);
return FALSE;
}
fseek(fptr, 0, SEEK_SET);
//check error for writing
if (fwrite(& (image -> header), sizeof(image->header), 1, fptr) != 1)
{
fclose (fptr);
return FALSE;
}
if (fwrite(image->data, (image->header).imagesize, 1, fptr) != 1)
{
fclose(fptr);
return FALSE;
}
fclose(fptr);
return TRUE;
}
void BMP_Free(BMPImage* image)
{
free(image->data);
free(image);
}