bmp文件存储时图像发生偏移

Question

本人在用VS2019进行bmp文件读取与存储时，彩色图像的输出图像与输入图像之间发生了偏移，但是灰度图像没有影响，请问是什么原因，代码如下

#include<Windows.h>
#include<stdio.h>
#include<iostream>
using namespace std;

unsigned char* pBmpBuf;//读入图像数据的指针
int bmpWidth;//图像的宽
int bmpHeight;//图像的高
RGBQUAD* pColorTable;//颜色表指针
int biBitCount;//图像类型

bool readBmp(char* bmpName)
{
    FILE* fp = fopen(bmpName, "rb");
    if (fp == 0) return 0;

    fseek(fp, sizeof(BITMAPFILEHEADER), 0);

    BITMAPINFOHEADER head;
    fread(&head, sizeof(BITMAPINFOHEADER), 1, fp);

    bmpWidth = head.biWidth;
    bmpHeight = head.biHeight;
    biBitCount = head.biBitCount;

    int lineByte = (bmpWidth * biBitCount/8+3)/4*4;

    if (biBitCount == 8) 
    {
        pColorTable = new RGBQUAD[256];
        fread(pColorTable, sizeof(RGBQUAD), 256, fp);
    }

    pBmpBuf = new unsigned char[lineByte * bmpHeight];
    fread(pBmpBuf, 1, lineByte * bmpHeight, fp);

    fclose(fp);
    return 1;
}

bool saveBmp(char* bmpName, unsigned char* imgBuf, int width, int height,int biBitCount, RGBQUAD* pColorTable)
{

    if (!imgBuf)
    {
        return 0;
    }

    int colorTablesize = 0;
    if (biBitCount == 8)
    {
        colorTablesize = 768;
    }

    int lineByte = (width * biBitCount/8+3)/4*4;

    FILE* fp = fopen(bmpName, "wb");
    if (fp == 0) { return 0; }

    BITMAPFILEHEADER fileHead;
    fileHead.bfType = 0x4D42;
    fileHead.bfSize = sizeof(BITMAPFILEHEADER) + sizeof(BITMAPINFOHEADER) + colorTablesize + lineByte * height;
    fileHead.bfReserved1 = 0;
    fileHead.bfReserved2 = 0;
    fileHead.bfOffBits = 54 + colorTablesize;
    fwrite(&fileHead, sizeof(BITMAPFILEHEADER), 1, fp);

    BITMAPINFOHEADER head;
    head.biBitCount = biBitCount;
    head.biClrImportant = 0;
    head.biClrUsed = 0;
    head.biCompression = 0;
    head.biHeight = height;
    head.biPlanes = 1;
    head.biSize = 40;
    head.biSizeImage = lineByte * height;
    head.biWidth = width;
    head.biXPelsPerMeter = 0;
    head.biYPelsPerMeter = 0;
    fwrite(&head, sizeof(BITMAPINFOHEADER), 1, fp);

    if (biBitCount == 8)
    {
        fwrite(pColorTable, sizeof(RGBQUAD), 256, fp);
    }
    fwrite(imgBuf, height * lineByte, 1, fp);
    
    fclose(fp);
    return 1;
}

void main()
{

    char readPath[]="C:\\Users\\123\\Desktop\\123.bmp";
    readBmp(readPath);

    cout<<"width="<<bmpWidth<<" "<<"height="<<bmpHeight <<" " << biBitCount;

    char writePath[]="C:\\Users\\123\\Desktop\\1231.bmp";
    saveBmp(writePath, pBmpBuf, bmpWidth, bmpHeight, biBitCount, pColorTable);

    delete []pBmpBuf;
    if(biBitCount==8)
        delete []pColorTable;
}

运行结果如下：

Answer 1

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