C++:比较 if 语句中的十进制值

我正在打印出.bmp文件中像素的值。我的问题是，如果像素不是 255 255 255（白色），那么我希望它是 0 0 0（黑色）。

完整的代码：（是的，这是从 24bpp 位图中获取每个像素的 RGB 值以转换为 C 格式的 GBA 格式）这适用于 24 位.bmp

#include <stdio.h>
#include <stdlib.h>
#pragma pack(2)

typedef struct
{
    char signature[2];
    unsigned int fileSize;
    unsigned int reserved;
    unsigned int offset;
} BmpHeader;
typedef struct
{
    unsigned int headerSize;
    unsigned int width;
    unsigned int height;
    unsigned short planeCount;
    unsigned short bitDepth;
    unsigned int compression;
    unsigned int compressedImageSize;
    unsigned int horizontalResolution;
    unsigned int verticalResolution;
    unsigned int numColors;
    unsigned int importantColors;
} BmpImageInfo;
typedef struct
{
    unsigned char blue;
    unsigned char green;
    unsigned char red;
    //unsigned char reserved; Removed for convenience in fread; info.bitDepth/8 doesn't seem to work for some reason
} Rgb;

int main( int argc, char **argv ) {
        FILE *inFile;
        BmpHeader header;
        BmpImageInfo info;
        Rgb *palette;
        int i = 0;
        printf( "Opening file %s for reading.n", argv[1] );
        inFile = fopen( argv[1], "rb" );
        if( !inFile ) {
                printf( "Error opening file %s.n", argv[1] );
            return -1;
        }
        if( fread(&header, 1, sizeof(BmpHeader), inFile) != sizeof(BmpHeader) ) {
                printf( "Error reading bmp header.n" );
            return -1;
        }
        if( fread(&info, 1, sizeof(BmpImageInfo), inFile) != sizeof(BmpImageInfo) ) {
                printf( "Error reading image info.n" );
            return -1;
        }
        if( info.numColors > 0 ) {
                printf( "Reading palette.n" );
                palette = (Rgb*)malloc(sizeof(Rgb) * info.numColors);
                if( fread(palette, sizeof(Rgb), info.numColors, inFile) != (info.numColors * sizeof(Rgb)) ) {
                        printf( "Error reading palette.n" );
                return -1; // error
                }
        }
        printf( "Opening file %s for writing.n", argv[2] );
        FILE *outFile = fopen( argv[2], "wb" );
        if( !outFile ) {
                printf( "Error opening outputfile.n" );
                return -1;
        }
        Rgb *pixel = (Rgb*) malloc( sizeof(Rgb) );
        int read, j;
        for( j=0; j<info.height; j++ ) {
                printf( "------ Row %dn", j+1 );
                read = 0;
                for( i=0; i<info.width; i++ ) {
                        if( fread(pixel, 1, sizeof(Rgb), inFile) != sizeof(Rgb) ) {
                                printf( "Error reading pixel!n" );
                                return -1;
                        }
                        read += sizeof(Rgb);
                        if (pixel->red != 255 || pixel->green != 255 || pixel->blue != 255)
                            printf( "Pixel %d: 0 0 0n", i+1, );
                        else
                            printf( "Pixel %d: %3d %3d %3dn", i+1, pixel->red, pixel->green, pixel->blue );
                        /*if (pixel->red != 255 || pixel->green != 255 || pixel->blue != 255)
                            printf ("Pixel %d: 0 0 0n", i+1);
                        else
                            printf( "Pixel %d: 255 255 255n", i+1);*/
                }
                if( read % 4 != 0 ) {
                        read = 4 - (read%4);
                        printf( "Padding: %d bytesn", read );
                        fread( pixel, read, 1, inFile );
                }
        }
        printf( "Done.n" );
        fclose(inFile);
        fclose(outFile);
        printf( "nBMP-Info:n" );
        printf( "Width x Height: %i x %in", info.width, info.height );
        printf( "Depth: %in", (int)info.bitDepth );
        return 0;
}