数码相框——8、3、2 程序编写_图片显示之缩放与合并

1、图像缩放算法

参考文件夹里： 图像缩放算法.htm

void PicZoom3_Table(const TPicRegion& Dst,const TPicRegion& Src)
{
    if (  (0==Dst.width)||(0==Dst.height)
        ||(0==Src.width)||(0==Src.height)) return;
    unsigned long dst_width=Dst.width;
    unsigned long* SrcX_Table = new unsigned long[dst_width];
    for (unsigned long x=0;x<dst_width;++x)//生成表 SrcX_Table
    {
        SrcX_Table[x]=(x*Src.width/Dst.width);
    }

    TARGB32* pDstLine=Dst.pdata;
    for (unsigned long y=0;y<Dst.height;++y)
    {
        unsigned long srcy=(y*Src.height/Dst.height);
        TARGB32* pSrcLine=((TARGB32*)((TUInt8*)Src.pdata+Src.byte_width*srcy));
        for (unsigned long x=0;x<dst_width;++x)
            pDstLine[x]=pSrcLine[SrcX_Table[x]];
        ((TUInt8*&)pDstLine)+=Dst.byte_width;
    }

    delete [] SrcX_Table;
}

解释下就是：

2、编写代码
在render目录下新建operation

在operation里建立

1）zoom.c

#include <pic_operation.h>
#include <stdlib.h>
#include <string.h>


int PicZoom(PT_PixelDatas ptOriginPic, PT_PixelDatas ptZoomPic)
{
    unsigned long dwDstWidth = ptZoomPic->iWidth;
    unsigned long* pdwSrcXTable = malloc(sizeof(unsigned long) * dwDstWidth);
	unsigned long x;
	unsigned long y;
	unsigned long dwSrcY;
	unsigned char *pucDest;
	unsigned char *pucSrc;
	unsigned long dwPixelBytes = ptOriginPic->iBpp/8;

	if (ptOriginPic->iBpp != ptZoomPic->iBpp)
	{
		return -1;
	}
	
    for (x = 0; x < dwDstWidth; x++)//生成表 pdwSrcXTable  Sx
    {
        pdwSrcXTable[x]=(x*ptOriginPic->iWidth/ptZoomPic->iWidth);
    }

    for (y = 0; y < ptZoomPic->iHeight; y++)
    {			
        dwSrcY = (y * ptOriginPic->iHeight / ptZoomPic->iHeight); //Sy

		pucDest = ptZoomPic->aucPixelDatas + y*ptZoomPic->iLineBytes;
		pucSrc  = ptOriginPic->aucPixelDatas + dwSrcY*ptOriginPic->iLineBytes;
		
        for (x = 0; x <dwDstWidth; x++)
        {
            /* 原图座标: pdwSrcXTable[x]，srcy
             * 缩放座标: x, y
			 */
			 memcpy(pucDest+x*dwPixelBytes, pucSrc+pdwSrcXTable[x]*dwPixelBytes, dwPixelBytes);
        }
    }

    free(pdwSrcXTable);
	return 0;
}

2）merge.c

#include <pic_operation.h>
#include <string.h>

int PicMerge(int iX, int iY, PT_PixelDatas ptSmallPic, PT_PixelDatas ptBigPic)
{
	int i;
	unsigned char *pucSrc;
	unsigned char *pucDst;
	
	if ((ptSmallPic->iWidth > ptBigPic->iWidth)  ||
		(ptSmallPic->iHeight > ptBigPic->iHeight) ||
		(ptSmallPic->iBpp != ptBigPic->iBpp))
	{
		return -1;
	}

	pucSrc = ptSmallPic->aucPixelDatas;
	pucDst = ptBigPic->aucPixelDatas + iY * ptBigPic->iLineBytes + iX * ptBigPic->iBpp / 8;
	for (i = 0; i < ptSmallPic->iHeight; i++)
	{
		memcpy(pucDst, pucSrc, ptSmallPic->iLineBytes);
		pucSrc += ptSmallPic->iLineBytes;
		pucDst += ptBigPic->iLineBytes;
	}
	return 0;
}

标签：ptZoomPic,缩放,ptSmallPic,相框,unsigned,long,数码,ptOriginPic,ptBigPic
来源： https://blog.csdn.net/qq_40674996/article/details/100578644