1 #include <stdio.h>
2 #include <stdlib.h>
3 #include <string.h>
4
5 int main(int argc, char *argv[])
6 {
7 int row, col;
8 int width, height, widthbyte, bitcount, imagesize, bytecount;
9 const char *magenta = NULL;
10 const char *magendiff = NULL;
11 unsigned char header[] =
12 {
13 0x42, 0x4D, 0xAA, 0xAA, 0xAA, 0xAA, 0x00, 0x00, // 2 AA->FileSize
14 0x00, 0x00, 0xBB, 0xBB, 0xBB, 0xBB, 0x28, 0x00, // 10 BB->OffBits
15 0x00, 0x00, 0xCC, 0xCC, 0xCC, 0xCC, 0xDD, 0xDD, // 18 CC->Width
16 0xDD, 0xDD, 0x01, 0x00, 0xEE, 0xEE, 0x00, 0x00, // 22 DD->Height
17 0x00, 0x00, 0xFF, 0xFF, 0xFF, 0xFF, 0x00, 0x00, // 28 EE->BitCount
18 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // 34 FF->ImageSize
19 0x00, 0x00, 0x00, 0x00, 0x00, 0x00
20 };
21
22 FILE *fpA = NULL;
23 FILE *fpB = NULL;
24 FILE *fpC = NULL;
25 const char *filenameA = "A.bmp";
26 const char *filenameB = "B.bmp";
27 const char *filenameC = "C.bmp";
28 unsigned char *rowbufA = NULL;
29 unsigned char *rowbufB = NULL;
30
31 const char * errmsg = NULL;
32
33 switch(argc)
34 {
35 case 1:
36 break;
37 case 2:
38 break;
39 case 3:
40 filenameA = argv[1];
41 filenameB = argv[2];
42 break;
43 case 4:
44 filenameA = argv[1];
45 filenameB = argv[2];
46 filenameC = argv[3];
47 break;
48 }
49
50 do
51 {
52 fpA = fopen(filenameA, "rb");
53 if(fpA == NULL) { errmsg = "A.bmp open failed"; break; };
54
55 fpB = fopen(filenameB, "rb");
56 if(fpB == NULL) { errmsg = "B.bmp open failed"; break; };
57
58 // read file A.bmp
59 fread(header, sizeof(header), 1L, fpA);
60 width = *((int *)(header + 18));
61 height = *((int *)(header + 22));
62 bitcount = *((short *)(header + 28));
63 imagesize = *((int *)(header + 34));
64 widthbyte = (width * bitcount + 31) / 32 * 4;
65 bytecount = bitcount / 8;
66 switch(bitcount)
67 {
68 case 16:
69 magenta = "\x1F\x7C";
70 magendiff = "\x1F\x7C";
71 break;
72 case 24:
73 case 32:
74 magenta = "\x00\x00\x00\x00";
75 magendiff = "\x00\x00\xFF\xFF";
76 break;
77 default:
78 errmsg = "A.bitcount != 16 or 24 or 32";
79 break;
80 }
81 if(errmsg) break;
82
83 // check file B.bmp
84 fread(header, sizeof(header), 1L, fpB);
85 if(width != *((int *)(header + 18))) { errmsg = "A.width != B.width"; break; }
86 if(height != *((int *)(header + 22))) { errmsg = "A.height != B.height"; break; }
87 if(bitcount != *((short *)(header + 28))) { errmsg = "A.bitcount != B.bitcount"; break; }
88 if(imagesize != *((int *)(header + 34))) { errmsg = "A.imagesize != B.imagesize"; break; }
89
90 rowbufA = (unsigned char *)malloc(widthbyte);
91 if(rowbufA == NULL) { errmsg = "rowbufA malloc failed"; break; }
92
93 rowbufB = (unsigned char *)malloc(widthbyte);
94 if(rowbufB == NULL) { errmsg = "rowbufB malloc failed"; break; }
95
96 fpC = fopen(filenameC, "wb");
97 if(fpC == NULL) { errmsg = "C.bmp open failed"; break; };
98
99 // wirte file C.bmp
100 fwrite(header, sizeof(header), 1L, fpC);
101 for(row = 0; row < height; row++)
102 {
103 fread(rowbufA, widthbyte, 1, fpA);
104 fread(rowbufB, widthbyte, 1, fpB);
105
106 for(col = 0; col < width; col++)
107 {
108 if(memcmp(rowbufA + bytecount * col, rowbufB + bytecount * col, bytecount) == 0)
109 {
110 memcpy(rowbufB + bytecount * col, magenta, bytecount);
111 }
112 else
113 {
114 memcpy(rowbufB + bytecount * col, magendiff, bytecount);
115 }
116 }
117
118 fwrite(rowbufB, widthbyte, 1, fpC);
119 }
120
121 } while(0);
122
123 if(fpA) fclose(fpA);
124 if(fpB) fclose(fpB);
125 if(fpC) fclose(fpC);
126 if(rowbufA) free(rowbufA);
127 if(rowbufB) free(rowbufB);
128
129 if(errmsg)
130 {
131 printf("%s\n", errmsg);
132 system("PAUSE");
133 }
134
135 return 0;
136 }
