【C++】插值函数代码分析学习

插值函数代码分析学习，用的CImage类load图像。

// Imagejoint.cpp : 定义控制台应用程序的入口点。
//
#include "stdafx.h"
#include "Imagejoint.h"
#include "math.h"
#include <afxwin.h> 
#ifdef _DEBUG
#define new DEBUG_NEW
#endif
#include <atlimage.h>//CImage类
#include <locale.h>

// The one and only application object

CWinApp theApp;

using namespace std;
//双三次插值系数
double fs(double w)
{    
        double a=-0.5;
        double fs;
        if (abs(w)<=1)
            fs=(a+2)*pow(abs(w),3)-(a+3)*pow(abs(w),2)+1;
        else if (abs(w)>1&&abs(w)<=2)
            fs=a*pow(abs(w),3)-5*a*pow(abs(w),2)+8*a*abs(w)-4*a;
        else
            fs=0;
        return fs;
}

HRESULT Imagejoint(PBYTE pbSrc,int iWidth,int iHeight,double dbRotate,double dbZoom,PBYTE pbTag);

int _tmain(int argc, TCHAR* argv[], TCHAR* envp[])
{

    int nRetCode = 0;//表示整数类型的函数返回码。n表示整数类型,Ret是Return的缩写,表示返回值,Code表示代码。
    setlocale(LC_ALL,"chs");
    HMODULE hModule = ::GetModuleHandle(NULL);

    if (hModule != NULL)
    {
        // initialize MFC and print and error on failure
        CImage cImage;
        HRESULT hResult;

        //初始化一些变量
        int        iWidth,iHeight,iBytePerPixel,iPitch;
        int        x,y;
        PBYTE    pbSrc=NULL,pbTag=NULL;//源图、目标图
        PBYTE    pbImage=NULL;//load图像后存在这
        PDWORD    pdwImage=NULL;//用于保存图像
        double    dbRotate=0,dbZoom=0;

        do{
            if (!AfxWinInit(hModule, NULL, ::GetCommandLine(), 0))
            {
                // TODO: change error code to suit your needs
                _tprintf(_T("Fatal Error: MFC initialization failed
"));
                nRetCode = 1;
                break;
            }
            // TODO: code your application's behavior here.
            if(argc<5)
            {
                _tprintf(_T("使用方法：Imagejoint 源图像文件 旋转角度 缩放倍数 输出文件
"));
                nRetCode= -1;
                break;
            }

            _stscanf(argv[2],_T("%lf"),&dbRotate);
            _stscanf(argv[3],_T("%lf"),&dbZoom);
            if(!((dbRotate>=0 && dbRotate<360) && (dbZoom>=0.25 && dbZoom<=16)))
            {
                _tprintf(_T("“旋转角度” 或 “缩放倍数”参数错误！
"));
                nRetCode= -2;
                break;
            }
            //Load 图像到cImage对象中
            hResult=cImage.Load(argv[1]);
            if(hResult!=ERROR_SUCCESS)
            {
                _tprintf(_T("源图像文件名错误！
"));
                nRetCode= -3;
                break;
            }
            
            iWidth=cImage.GetWidth();
            iHeight=cImage.GetHeight();
            //分配源图内存
            pbSrc = (PBYTE)malloc(iWidth*iHeight);
            //分配目标图内存
            if(dbZoom>1) pbTag = (PBYTE)malloc(ceil(iWidth*dbZoom)*ceil(iHeight*dbZoom));
            else         pbTag = (PBYTE)malloc(iWidth*iHeight);
            if(pbSrc==NULL || pbTag==NULL )
            {
                _tprintf(_T("内存申请错误！
"));
                nRetCode= -4;
                break;
            }
            //cImage数据存到pbImage，后再转换为源灰度图pbSrc
            iPitch=cImage.GetPitch();
            iBytePerPixel=(cImage.GetBPP()+7)/8;
            if(iBytePerPixel==3)
            {
                for(y=0;y<iHeight;y++)
                {   //load的图像数据放到pbImage
                    pbImage=(PBYTE)(PBYTE(cImage.GetBits())+iPitch*y);//得到的是图像初始像素地址
                    for(x=0;x<iWidth;x++)
                    {
                        //pbImage转换为灰度图pbSrc
                        pbSrc[y*iWidth+x]=(pbImage[3*x]*0.15+pbImage[3*x+1]*0.55+pbImage[3*x+2]*0.3);
                    }
                }
            }
            cImage.Destroy();
            //TO DO:执行操作
            hResult=Imagejoint(pbSrc,iWidth,iHeight,dbRotate,dbZoom,pbTag);
            if(hResult!=ERROR_SUCCESS)
            {
                _tprintf(_T("图像处理错误！
"));
                nRetCode= -5;
                break;
            }


            //处理后保存图像
            iWidth=ceil(iWidth*dbZoom);
            iHeight=ceil(iHeight*dbZoom);
            cImage.Create(iWidth,-iHeight,32);
            iPitch=cImage.GetPitch();
            for(y=0;y<iHeight;y++)
            {
                pdwImage=(PDWORD)(PBYTE(cImage.GetBits())+iPitch*y);
                for(x=0;x<iWidth;x++)
                {
                    pdwImage[x]=pbTag[y*iWidth+x]*0x10101;  
                }
            }
            //待保存图像文件名
            CString csTagName=argv[4];
            csTagName.Trim();
            csTagName.MakeUpper();
            if(csTagName.Right(4)!=_T(".BMP") ) csTagName.Append(_T(".BMP"));
            hResult=cImage.Save(csTagName);
            if(hResult!=ERROR_SUCCESS)
            {
                _tprintf(_T("图像结果保存错误！
"));
                nRetCode= -5;
                break;
            }
            _tprintf(_T("图像处理成功！
"));
            nRetCode= ERROR_SUCCESS;
            break;
        }while(0);
        if(pbSrc) free(pbSrc);
        if(pbTag) free(pbTag);
    }
    else
    {
        //  可以根据需求更改错误提示
        _tprintf(_T("Fatal Error: GetModuleHandle failed
"));
        nRetCode = 1;
    }
    getchar();    
    return nRetCode;
}

HRESULT Imagejoint(PBYTE pbSrc,int iWidth,int iHeight,double dbRotate,double dbZoom,PBYTE pbTag)
{
    int size;
    if(dbZoom>1)
    {
        size=iWidth*iHeight;
    }
    else
    {
        size=ceil(iWidth*dbZoom)*ceil(iHeight*dbZoom);
    }
    //旋转中心为图像中心
    double rx0=iWidth;  
    double ry0=iHeight; 
    double srcx,srcy,u,v;
    int xOr,yOr;
    //int zoom=ceil(dbZoom);
    dbRotate=dbRotate*3.1415926/180.0;
    for (int y=0;y<dbZoom*iHeight;y++)
    {
        for (int x=0;x<dbZoom*iWidth;x++)
        {
            srcx=(double)((x-rx0)*cos(dbRotate) - (y-ry0)*sin(dbRotate) + rx0) ;
            srcy=(double)((x-rx0)*sin(dbRotate) + (y-ry0)*cos(dbRotate) + ry0) ;
            srcx=srcx*1/dbZoom;
            srcy=srcy*1/dbZoom;
            xOr = floor(srcx);
            yOr = floor(srcy);
            u=srcx-xOr;
            v=srcy-yOr;

            if( !(srcx>=0 && srcx<=iWidth && srcy>=0 && srcy<=iHeight))
                {
                    pbTag[y*2*iWidth+x]=0;//255
                }
            else
            {   
                double middle=
                    pbSrc[(yOr-1)*iWidth+(xOr-1)]*fs(1+u)*fs(1+v)+
                    pbSrc[(yOr)*iWidth+(xOr-1)]*fs(1+u)*fs(v)+
                    pbSrc[(yOr+1)*iWidth+(xOr-1)]*fs(1+u)*fs(1-v)+
                    pbSrc[(yOr+2)*iWidth+(xOr-1)]*fs(1+u)*fs(2-v)+
                    
                    pbSrc[(yOr-1)*iWidth+(xOr)]*fs(u)*fs(1+v)+
                    pbSrc[(yOr)*iWidth+(xOr)]*fs(u)*fs(v)+
                    pbSrc[(yOr+1)*iWidth+(xOr)]*fs(u)*fs(1-v)+
                    pbSrc[(yOr+2)*iWidth+(xOr)]*fs(u)*fs(2-v)+

                    pbSrc[(yOr-1)*iWidth+(xOr+1)]*fs(1-u)*fs(1+v)+
                    pbSrc[(yOr)*iWidth+(xOr+1)]*fs(1-u)*fs(v)+
                    pbSrc[(yOr+1)*iWidth+(xOr+1)]*fs(1-u)*fs(1-v)+
                    pbSrc[(yOr+2)*iWidth+(xOr+1)]*fs(1-u)*fs(2-v)+

                    pbSrc[(yOr-1)*iWidth+(xOr+2)]*fs(2-u)*fs(1+v)+
                    pbSrc[(yOr)*iWidth+(xOr+2)]*fs(2-u)*fs(v)+
                    pbSrc[(yOr+1)*iWidth+(xOr+2)]*fs(2-u)*fs(1-v)+
                    pbSrc[(yOr+2)*iWidth+(xOr+2)]*fs(2-u)*fs(2-v);

                if(middle<=255&&middle>=0)
                    pbTag[y*2*iWidth+x]=middle;
                else if(middle>255)
                    pbTag[y*2*iWidth+x]=255;
                else 
                    pbTag[y*2*iWidth+x]=0;
            }
        }
    }
    //memcpy(pbTag,pbSrc,size);
    return ERROR_SUCCESS;
}