linux下rgb转bmp

#include <stdio.h>
#include <stdlib.h>

typedef struct {
    unsigned char blue;
    unsigned char green;
    unsigned char red;
} RGB;

typedef struct {
    unsigned short bfType;
    unsigned int bfSize;
    unsigned short bfReserved1;
    unsigned short bfReserved2;
    unsigned int bfOffBits;
} BMPHeader;

typedef struct {
    unsigned int biSize;
    int biWidth;
    int biHeight;
    unsigned short biPlanes;
    unsigned short biBitCount;
    unsigned int biCompression;
    unsigned int biSizeImage;
    int biXPelsPerMeter;
    int biYPelsPerMeter;
    unsigned int biClrUsed;
    unsigned int biClrImportant;
} BMPInfoHeader;

void writeBMP(const char* filename, RGB* data, int width, int height) {
    FILE* file = fopen(filename, "wb");
    if (!file) {
        perror("Failed to open file for writing");
        return;
    }

    BMPHeader header;
    BMPInfoHeader infoHeader;

    header.bfType = 0x4D42; // "BM"
    header.bfSize = sizeof(BMPHeader) + sizeof(BMPInfoHeader) + width * height * 3;
    header.bfReserved1 = 0;
    header.bfReserved2 = 0;
    header.bfOffBits = sizeof(BMPHeader) + sizeof(BMPInfoHeader);

    infoHeader.biSize = sizeof(BMPInfoHeader);
    infoHeader.biWidth = width;
    infoHeader.biHeight = height;
    infoHeader.biPlanes = 1;
    infoHeader.biBitCount = 24;
    infoHeader.biCompression = 0; // BI_RGB, no compression
    infoHeader.biSizeImage = width * height * 3;
    infoHeader.biXPelsPerMeter = 0;
    infoHeader.biYPelsPerMeter = 0;
    infoHeader.biClrUsed = 0;
    infoHeader.biClrImportant = 0;

    fwrite(&header, sizeof(BMPHeader), 1, file);
    fwrite(&infoHeader, sizeof(BMPInfoHeader), 1, file);

    // BMP stores pixels in BGR order and bottom-up
    for (int y = height - 1; y >= 0; --y) {
        for (int x = 0; x < width; ++x) {
            RGB pixel = data[y * width + x];
            fwrite(&pixel.blue, 1, 1, file);
            fwrite(&pixel.green, 1, 1, file);
            fwrite(&pixel.red, 1, 1, file);
        }
    }

    fclose(file);
}

int main() {
    // Example usage
    RGB image[] = { /* ... your RGB data here ... */ };
    writeBMP("output.bmp", image, 640, 480);
    return 0;
}