c - 使用C

Question

[编辑] 现在我可以分配像素数组来获取BMP图片的二维数组。

但我不知道如何计算该图片的红绿色或蓝色像素，因为它们需要3位来存储彩色RGB。

我正在尝试使用C来计算我的图片中有多少灰色像素。 我已经使用结构打开了BMP文件，可以读取bmp文件的所有细节，比如高度，宽度......

[编辑过的代码]

#include <stdio.h>
#include <stdlib.h>
#pragma pack(push)  // push current alignment to stack
#pragma pack(1)     // set alignment to 1 byte boundary

typedef struct
{
    unsigned short int Type; /* Magic identifier */
    unsigned int Size; /* File size in bytes */
    unsigned short int Reserved1;
    unsigned short int Reserved2;
    unsigned int Offset; /* Offset to data (in B)*/
}HEADER; /* -- 14 Bytes -- */

typedef struct
{
   unsigned int Size; /* Header size in bytes */
    int Width;
    int Height; /* Width / Height of image */
    unsigned short int Planes; /* Number of colour planes */
    unsigned short int Bits; /* Bits per pixel */
    unsigned int Compression; /* Compression type */
    unsigned int ImageSize; /* Image size in bytes */
    int xResolution;
    int yResolution;/* Pixels per meter */
    unsigned int Colors; /* Number of colors */
    unsigned int ImportantColors;/* Important colors */
}INFOHEADER; /* -- 40 Bytes -- */
    typedef struct
    {
        unsigned char Red;
        unsigned char Green;
        unsigned char Blue;
    }PIXEL;
#pragma pack(pop)   // restore original alignment from stack

int main()
{
    HEADER data;
    INFOHEADER data2;
    PIXEL pixel;

    FILE *file;
    file = fopen("lena512.bmp","rb");

    fread(&data,sizeof(HEADER),1,file);
    //read IB+NFOHEADER data into data2
    fread(&data2,sizeof(INFOHEADER),1,file);


    printf("Height: %d\n",data2.Height);
    printf("Witdh: %d\n" ,data2.Width);

 //Allocate space for pixelarray
    PIXEL **pixelarray;

    int r=0,c=0,rows=data2.Height,columns=data2.Width;

    pixelarray= malloc(rows*sizeof(PIXEL *));

    for(r=0; r<rows; r++)
    {
        pixelarray[r]=malloc(columns*sizeof(PIXEL));
    }

    //fill pixel array with pixel structs
    int pixelnum=0;

for( r=0; r<rows; r++ )
{
for( c=0; c<columns; c++ )     // read pixel data from image
{
    fread(&pixelarray[r][c].Red , 1, sizeof(PIXEL), file);
    fread(&pixelarray[r][c].Green , 1, sizeof(PIXEL), file);
    fread(&pixelarray[r][c].Blue , 1, sizeof(PIXEL), file);
    if(pixelarray[r][c].Red=pixelarray[r][c].Green=pixelarray[r][c].Blue)
        pixelnum++;

}
}
printf("Gray num: %d\n",pixelnum);

fclose(file);  //close the files prior to exiting
}

[编辑] 这部分我在网上找到了，为什么他们把.Red放在二维阵列之后？

fread(&pixelarray[r][c].Red , 1, sizeof(PIXEL), file);
fread(&pixelarray[r][c].Green , 1, sizeof(PIXEL), file);
fread(&pixelarray[r][c].Blue , 1, sizeof(PIXEL), file);

但后来我不知道如何访问我的图像的颜色像素级别了。任何人都可以帮助我吗？ 我想我应该再为像素制作一个结构，但正如我在论坛上发现的只有红色，绿色和蓝色但没有灰色值。很抱歉不知道任何事情......