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zhiyb/channel.c

Created May 25, 2019 14:19
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Ancient BMP file RGB channel conversion code
Raw
channel.c
#include <stdio.h>
#include <inttypes.h>
#define NONE 0
#define BLUE 1
#define GREEN 2
#define RED 3
int getRGB(void)
{
get:
switch (getchar()) {
case 'R':
case 'r':
return RED;
case 'G':
case 'g':
return GREEN;
case 'B':
case 'b':
return BLUE;
case 'N':
case 'n':
return NONE;
}
goto get;
}
int main(int argc, char *argv[])
{
uint32_t i, offset, c, r, g, b;
FILE *in, *out;
if (argc != 3) {
fputs("Arg error!\n", stderr);
return 1;
}
in = fopen(argv[1], "r");
out = fopen(argv[2], "w");
if (in == NULL || out == NULL) {
fputs("File error!\n", stderr);
return 2;
}
for (i = 0; i < 10; i++)
fputc(fgetc(in), out);
fputc(i = fgetc(in), out);
offset = (uint32_t)i;
fputc(i = fgetc(in), out);
offset |= (uint32_t)i << 8;
fputc(i = fgetc(in), out);
offset |= (uint32_t)i << 16;
fputc(i = fgetc(in), out);
offset |= (uint32_t)i << 24;
for (i = 14; i < offset; i++)
fputc(fgetc(in), out);
puts("Choose colour input channel: [RGB]");
c = getRGB();
puts("Set colour: [RRGGBB]");
scanf("%2X%2X%2X", &r, &g, &b);;
while (1) {
int rgb[4];
rgb[NONE] = 0;
rgb[BLUE] = fgetc(in); // Blue
rgb[GREEN] = fgetc(in); // Green
rgb[RED] = fgetc(in); // Red
if (rgb[0] == EOF || rgb[1] == EOF || rgb[2] == EOF)
break;
fputc(rgb[c] * b / 255, out); // Blue
fputc(rgb[c] * g / 255, out); // Green
fputc(rgb[c] * r / 255, out); // Red
}
fclose(in);
fclose(out);
return 0;
}
Raw
conv.c
#include <stdio.h>
#include <inttypes.h>
#define NONE 0
#define BLUE 1
#define GREEN 2
#define RED 3
int getRGB(void)
{
get:
switch (getchar()) {
case 'R':
case 'r':
return RED;
case 'G':
case 'g':
return GREEN;
case 'B':
case 'b':
return BLUE;
case 'N':
case 'n':
return NONE;
}
goto get;
}
int main(int argc, char *argv[])
{
uint32_t i, offset, r, g, b;
FILE *in, *out;
if (argc != 3) {
fputs("Arg error!\n", stderr);
return 1;
}
in = fopen(argv[1], "r");
out = fopen(argv[2], "w");
if (in == NULL || out == NULL) {
fputs("File error!\n", stderr);
return 2;
}
for (i = 0; i < 10; i++)
fputc(fgetc(in), out);
fputc(i = fgetc(in), out);
offset = (uint32_t)i;
fputc(i = fgetc(in), out);
offset |= (uint32_t)i << 8;
fputc(i = fgetc(in), out);
offset |= (uint32_t)i << 16;
fputc(i = fgetc(in), out);
offset |= (uint32_t)i << 24;
for (i = 14; i < offset; i++)
fputc(fgetc(in), out);
puts("Choose colour replace method: [RGB]");
r = getRGB();
g = getRGB();
b = getRGB();
while (1) {
int rgb[4];
rgb[NONE] = 0;
rgb[BLUE] = fgetc(in); // Blue
rgb[GREEN] = fgetc(in); // Green
rgb[RED] = fgetc(in); // Red
if (rgb[0] == EOF || rgb[1] == EOF || rgb[2] == EOF)
break;
fputc(rgb[b], out); // Blue
fputc(rgb[g], out); // Green
fputc(rgb[r], out); // Red
}
fclose(in);
fclose(out);
return 0;
}
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