Cimage类处理图像像素(数据)的3种方式(转)
这里只讨论对图像像素的处理,cimage类的具体用法查相关资料
#include <atlimage.h> //VS2010以后不用加这个
……………………
CImage m_Image; //或CImage* m_Image; 下面例子程序我用的CImage m_Image; 只是一个用成员选择符,一个用指针操作,效率上可能有所差异
下面是3种方法:
一、用Cimage类的成员函数进行处理
这里假设你已经加载了图像位图,并与CImage对象m_Image相关联。相关成员函数主要有:
GetPixel 返回像素颜色
SetPixel 设置像素颜色
如:m_Image.SetPixel( i-1, j-1, RGB(rr,gg,bb));
SetPixelRGB 设置像素的红绿蓝
如:m_Image.SetPixelRGB(x,y,avg,avg,avg);
SetColorTable 设置调色板颜色分量(红、绿、蓝)值
GetWidth 宽度(以像素为单位)
GetHeight 高度
1、程序示例
1)一个双线性插值放大程序。
- if (m_Image.IsNull())
- return;
- // 创建对话框
- DlgInterpolation TranPara;
- //显示对话框,提示用户设定量
- if (TranPara.DoModal() != IDOK)
- return;
- int k=TranPara.m_inter;
- BeginWaitCursor();
- CImage m_Image1;
- if (! m_Image1.IsNull())
- {
- m_Image1.Destroy();
- }
- m_Image1.Create( m_Image.GetWidth()*k, m_Image.GetHeight()*k, 24,0);
- // 四个最临近象素的坐标
- int x1, x2;
- int y1, y2;
- // 四个最临近象素值
- unsigned char f1, f2, f3, f4;
- // 二个插值中间值
- unsigned char f12, f34;
- //计算结果
- int fr,fb,fg;
- double epsilon = 0.001;
- COLORREF pixel11,pixel12,pixel21,pixel22;
- int nHeight1 = m_Image1.GetHeight();
- int nWidth1 = m_Image1.GetWidth();
- int nHeight = m_Image.GetHeight();
- int nWidth = m_Image.GetWidth();
- double m=((double)nWidth1-1)/((double)nWidth-1);
- for (int i=0; i<nWidth1; i++)
- {
- for (int j=0; j<nHeight1; j++)
- {
- double x=double((double)i/m);
- double y=double((double)j/m);
- //计算四个最临近象素的坐标,+1向右下方移动
- x1 = (int) x;
- x2 = x1 + 1;
- y1 = (int) y;
- y2 = y1 + 1;
- if( (x < 0) || (x > nWidth - 1) || (y < 0) || (y > nHeight - 1))
- {
- //要计算的点不在源图范围内,返回-1
- continue;
- }
- else
- {
- if (fabs(x - nWidth + 1) <= epsilon )
- {
- // 要计算的点在图像右边缘上
- if (fabs(y -nHeight + 1) <= epsilon)
- {
- // 要计算的点正好是图像最右下角那一个象素,直接返回该点象素值
- pixel11 = m_Image.GetPixel(x1,y1);
- f1 = (unsigned char)GetRValue(pixel11);
- fr=(int)f1;
- f1 = (unsigned char)GetGValue(pixel11);
- fg=(int)f1;
- f1 = (unsigned char)GetBValue(pixel11);
- fb=(int)f1;
- }
- else
- {
- // 在图像右边缘上且不是最后一点,直接一次插值即可
- pixel11 = m_Image.GetPixel(x1,y1);
- pixel12 = m_Image.GetPixel(x1,y2);
- f1 = (unsigned char)GetRValue(pixel11);
- f3 = (unsigned char)GetRValue(pixel12);
- fr= (int) (f1 + (y -y1) * (f3 - f1));
- f1 = (unsigned char)GetGValue(pixel11);
- f3 = (unsigned char)GetGValue(pixel12);
- fg= (int) (f1 + (y -y1) * (f3 - f1));
- f1 = (unsigned char)GetBValue(pixel11);
- f3 = (unsigned char)GetBValue(pixel12);
- fb= (int) (f1 + (y -y1) * (f3 - f1));
- }
- }
- else if (fabs(y - nHeight + 1) <= epsilon)
- {
- // 要计算的点在图像下边缘上且不是最后一点,直接一次插值即可
- pixel11 = m_Image.GetPixel(x1,y1);
- pixel21 = m_Image.GetPixel(x2,y1);
- f1 = (unsigned char)GetRValue(pixel11);
- f2 = (unsigned char)GetRValue(pixel21);
- fr=(int) (f1 + (x -x1) * (f2 - f1));
- f1 = (unsigned char)GetGValue(pixel11);
- f2 = (unsigned char)GetGValue(pixel21);
- fg=(int) (f1 + (x -x1) * (f2 - f1));
- f1 = (unsigned char)GetBValue(pixel11);
- f2 = (unsigned char)GetBValue(pixel21);
- fb=(int) (f1 + (x -x1) * (f2 - f1));
- }
- else
- {
- pixel11 = m_Image.GetPixel(x1,y1);
- pixel12 = m_Image.GetPixel(x1,y2);
- pixel21 = m_Image.GetPixel(x2,y1);
- pixel22 = m_Image.GetPixel(x2,y2);
- // 计算四个最临近象素值
- f1 = (unsigned char)GetRValue(pixel11);
- f2 = (unsigned char)GetRValue(pixel21);
- f3 = (unsigned char)GetRValue(pixel12);
- f4 = (unsigned char)GetRValue(pixel22);
- f12 = (unsigned char) (f1 + (x - x1) * (f2 - f1));
- f34 = (unsigned char) (f3 + (x - x1) * (f4 - f3));
- fr= (int) (f12 + (y -y1) * (f34 - f12));
- f1 = (unsigned char)GetGValue(pixel11);
- f2 = (unsigned char)GetGValue(pixel21);
- f3 = (unsigned char)GetGValue(pixel12);
- f4 = (unsigned char)GetGValue(pixel22);
- f12 = (unsigned char) (f1 + (x - x1) * (f2 - f1));
- f34 = (unsigned char) (f3 + (x - x1) * (f4 - f3));
- fg= (int) (f12 + (y -y1) * (f34 - f12));
- f1 = (unsigned char)GetBValue(pixel11);
- f2 = (unsigned char)GetBValue(pixel21);
- f3 = (unsigned char)GetBValue(pixel12);
- f4 = (unsigned char)GetBValue(pixel22);
- f12 = (unsigned char) (f1 + (x - x1) * (f2 - f1));
- f34 = (unsigned char) (f3 + (x - x1) * (f4 - f3));
- fb= (int) (f12 + (y -y1) * (f34 - f12));
- }
- }
- m_Image1.SetPixel(i,j, RGB(fr,fg,fb));
- }
- }
- m_Image.Destroy();
- m_Image.Create( m_Image1.GetWidth(), m_Image1.GetHeight(), 24, 0);
- COLORREF pixel;
- for (int i=0; i<nWidth1; i++)
- {
- for (int j=0; j<nHeight1; j++)
- {
- pixel = m_Image1.GetPixel(i,j);
- int y=GetRValue(pixel);
- int p=GetGValue(pixel);
- int b=GetBValue(pixel);
- m_Image.SetPixelRGB(i,j,GetRValue(pixel),GetGValue(pixel),GetBValue(pixel));
- }
- }
- m_Image1.Destroy();
- Invalidate();
- EndWaitCursor();
2)处理视频帧
- ……
- Defog(imageprosses, nimgWidth, nimgheigt);/*我加的一个雾天图像增强的动态库,imageprosses是视频的一帧,输入imageprosses处理,并输出imageprosses*/
- int rr = 0, gg = 0, bb = 0;
- for (int i = 0; i < nimgWidth; i++)
- {
- for (int j = 1; j <= nimgheigt; j++)
- {
- bb=(int)imageprosses[3*i*j];
- gg=(int)imageprosses[3*i*j+1];
- rr=(int)imageprosses[3*i*j+2];
- m_Image.SetPixel(i, j-1, RGB(rr,gg,bb));/*设置一帧图像的像素值用来显示*/
- }
- }
- ……
2、比较:非常慢。一个图像数据一般很大的,函数调用、参数传递会更加耗时。
二、直接对内存进行操作
相关成员函数:
GetPitch 行距
GetBPP 每像素位数,用时记得GetBPP()/8
GetBits 返回图像像素数据指针
1、程序示例
- ……
- Defog(imageprosses, nimgWidth, nimgheigt);
- //调用cimage类
- if (m_Image.IsNull())
- m_Image.Create( nimgWidth, nimgheigt, 24,0);
- //地址访问方式
- byte* pRealData;
- //首地址
- pRealData=(byte*)m_Image.GetBits();
- //行距
- int pit=m_Image.GetPitch();
- for (int i = 0; i <nimgWidth; i++)
- {
- for (int j = 0; j < nimgheigt; j++)
- {
- *(pRealData + pit*j+ i*3)=(int)imageprosses[3*(nimgheigt-1-j)*nimgWidth+3*i];
- *(pRealData + pit*j +i*3 +1)=(int)imageprosses[3*(nimgheigt-1-j)*nimgWidth+3*i+1];
- *(pRealData + pit*j + i*3 +2)=(int)imageprosses[3*(nimgheigt-1-j)*nimgWidth+3*i+2];
- }
- }
- m_Image.Draw(pDC->m_hDC,0,0,nWidth,nheigt);
- ……
2、比较: 对地址直接操作最快,不需要多余的转换。
三、用数组进行处理
如果处理比较复杂的话,可把所有点颜色全部读到一个二维数组里面,然后对这个数组进行读写和处理。 再把处理后的图像显示出来。最方便的是可以进行一些自己需要的预处理,比如我是这样做的。
首先定义一个相关头文件和源文件处理相关内存操作
//MYIMAGE.h
- #if !defined(MyIMAGE)
- #define MyIMAGE
- #if _MSC_VER > 1000
- #pragma once
- #endif // _MSC_VER > 1000
- #include "windows.h"
- // 灰度图
- typedef byte **MYIMAGE;/*二维数组的数组名就是一个指向指针的指针,a的作用相当于**a,而a->[0],相当于a[0][0]*/
- //彩色图
- typedef struct MYCOLORIMAGESTRUCT
- {
- MYIMAGE r, g, b;
- }MYCOLORIMAGE;
- ////// 8bit图像操作
- // 8bit图像分配
- MYIMAGE MyImageAlloc(int height,int width);
- // 8bit图像释放
- void MyImageFree(MYIMAGE a, int height);
- // 8bit图像拷贝
- bool MyImageCopy(MYIMAGE dest, MYIMAGE source, int width, int height);
- // 8bit图像设置
- void MyImageSet(MYIMAGE a, int value, int width, int height);
- ////// 24bit图像操作
- // 24bit图像分配
- MYCOLORIMAGE MyColorImageAlloc(int height,int width);
- // 24bit图像释放
- void MyColorImageFree(MYCOLORIMAGE a, int height);
- // 24bit图像拷贝
- bool MyColorImageCopy(MYCOLORIMAGE dest, MYCOLORIMAGE source, int width, int height);
- // 24bit图像设置
- void MyColorImagSet(MYCOLORIMAGE a, int value, int width, int height);
- // 彩色图像转灰度图象
- bool MyColorToGray(MYIMAGE outGrayImg, MYCOLORIMAGE inColorImg, int width, int Height);
- #endif MyIMAGE
//MYIMAGE.cpp
- #include "StdAfx.h"
- #include "MYIMAGE.h"
- //灰度图像
- /**************my分配内存空间***************/
- MYIMAGE MyImageAlloc(int height,int width)
- {
- MYIMAGE a = (MYIMAGE) new MYIMAGE*[height];//数组指针
- int i;
- byte* pTemp;
- pTemp = new UCHAR[height*width];
- for(i = 0; i < height; i++)
- {
- a[i] = pTemp + width * i;
- }
- return a;
- }
- /*********释放内存空间***************/
- void MyImageFree(MYIMAGE a, int height)
- {
- delete[] a[0];
- delete a;
- }
- /*******拷贝************/
- bool MyImageCopy(MYIMAGE dest, MYIMAGE source, int width, int height)
- {
- if(dest == NULL || source == NULL || width <= 0 || height <= 0)
- return false;
- int i = 0;
- for(i = 0; i < height; i++)
- {
- memcpy(dest[i], source[i], sizeof(UCHAR) * width);
- }
- return true;
- }
- /*******赋值*******/
- void MyImageSet(MYIMAGE a, int value, int width, int height)
- {
- int i;
- for(i = 0; i < height; i++)
- {
- memset(a[i], value, sizeof(UCHAR) * width);
- }
- }
- //彩色图像
- /**************my彩色图像分配内存空间**********************/
- MYCOLORIMAGE MyColorImageAlloc(int height,int width)
- {
- //MYCOLORIMAGE a = (MYCOLORIMAGE) new char[sizeof(MYIMAGE) * 3];
- MYCOLORIMAGE a;
- a.r = MyImageAlloc(height,width);
- a.g = MyImageAlloc(height,width);
- a.b = MyImageAlloc(height,width);
- return a;
- }
- /****************my彩色图像空间内存释放*********************/
- void MyColorImageFree(MYCOLORIMAGE a, int height)
- {
- /*
- MyImageFree(a->r, height);
- MyImageFree(a->g, height);
- MyImageFree(a->b, height);
- delete a;
- */
- MyImageFree(a.r, height);
- MyImageFree(a.g, height);
- MyImageFree(a.b, height);
- }
- /***************my彩色图像拷贝******************/
- bool MyColorImageCopy(MYCOLORIMAGE dest, MYCOLORIMAGE source, int width, int height)
- {
- /*
- if(dest == NULL || source == NULL || width <= 0 || height <= 0)
- return false;
- int i = 0;
- for(i = 0; i < height; i++)
- {
- memcpy(dest->r[i], source->r[i], sizeof(UCHAR) * width);
- memcpy(dest->g[i], source->g[i], sizeof(UCHAR) * width);
- memcpy(dest->b[i], source->b[i], sizeof(UCHAR) * width);
- }
- return true;
- */
- if(dest.r == NULL || source.r == NULL || width <= 0 || height <= 0)
- return false;
- for(int i = 0; i < height; i++)
- {
- memcpy(dest.r[i], source.r[i], sizeof(UCHAR) * width);
- memcpy(dest.g[i], source.g[i], sizeof(UCHAR) * width);
- memcpy(dest.b[i], source.b[i], sizeof(UCHAR) * width);
- }
- return true;
- }
- /**********my彩色图像赋值*****************/
- void MyColorImagSet(MYCOLORIMAGE a, int value, int width, int height)
- {
- int i;
- for(i = 0; i < height; i++)
- {
- memset(a.r[i], value, sizeof(UCHAR) * width);
- memset(a.g[i], value, sizeof(UCHAR) * width);
- memset(a.b[i], value, sizeof(UCHAR) * width);
- }
- }
- /**********my彩色图转为灰度图**************/
- bool MyColorToGray(MYIMAGE outGrayImg, MYCOLORIMAGE inColorImg, int width, int Height)
- {
- if(outGrayImg == NULL || inColorImg.r == NULL || width <= 0 || Height <= 0)
- return false;
- for(int j = 0; j < Height; j++)
- {
- for(int i = 0; i < width; i++)
- {
- outGrayImg[j][i] = (int)(0.3 * inColorImg.r[j][i] + 0.59 * inColorImg.g[j][i] + 0.11 * inColorImg.b[j][i]);
- }
- }
- return TRUE;
- }
然后一些预处理操作,如格式间转换:
//ImageTransform.h
- #if !defined(ImageTransform)
- #define ImageTransform
- #if _MSC_VER > 1000
- #pragma once
- #endif // _MSC_VER > 1000
- //#include "ximage.h"
- #include "MYIMAGE.h"
- #include "atlimage.h"
- //CImage到MYIMAGE之间的格式转换
- //灰度
- // CImage转换成MYIMAGE
- BOOL CxImageToMYIMAGE(MYIMAGE destpImgbuf, CImage& sourpCxImage, int nImgWidth, int nImgHeight);
- // MYIMAGE转换成CImage
- BOOL MYIMAGEToCxImage(CImage& destpCxImage, MYIMAGE sourpImgbuf, int nImgWidth, int nImgHeight);
- //彩色
- // CImage转换成MYCOLORIMAGE
- BOOL CxxImageToMYIMAGE(MYCOLORIMAGE destpImgbuf, CImage& sourpCxImage, int nImgWidth, int nImgHeight);
- // MYCOLORIMAGE转换成CImage
- BOOL MYIMAGEToCxxImage(CImage& destpCxImage, MYCOLORIMAGE sourpImgbuf, int nImgWidth, int nImgHeight);
- #endif ImageTransform
//ImageTransform.cpp
- #include "StdAfx.h"
- #include "ImageTransform.h"
- //灰度
- // CImage转换成MYIMAGE
- BOOL CxImageToMYIMAGE(MYIMAGE destpImgbuf, CImage& sourpCxImage, int nImgWidth, int nImgHeight)
- {
- // 参数检查
- if(destpImgbuf == NULL || sourpCxImage == NULL || nImgWidth <= 0 || nImgHeight <= 0)
- return FALSE;
- int i, j;
- COLORREF rgb;
- //8位灰度图转存为8位灰度图
- if(sourpCxImage.GetBPP()/8 ==1)
- {
- for(j = 0; j < nImgHeight; j++)
- {
- for(i = 0; i < nImgWidth; i++)
- {
- destpImgbuf[j][i] = (byte)sourpCxImage.GetPixel(i, j);
- }
- }
- }
- //24位灰度图象转换为8位灰度图
- else if(sourpCxImage.GetBPP()/8==3)
- {
- for(j = 0; j < nImgHeight; j++)
- {
- for(i = 0; i < nImgWidth; i++)
- {
- rgb = sourpCxImage.GetPixel(i, j);
- destpImgbuf[j][i] = GetRValue(rgb);
- }
- }
- }
- return TRUE;
- }
- // MYIMAGE转换成CImage
- BOOL MYIMAGEToCxImage(CImage& destpCxImage, MYIMAGE sourpImgbuf, int nImgWidth, int nImgHeight)
- {
- // 参数检查
- if(destpCxImage == NULL || sourpImgbuf == NULL || nImgWidth <= 0 || nImgHeight <= 0)
- return FALSE;
- int i, j;
- //8位灰度图转换为24位灰度图
- for(j = 0; j < nImgHeight; j++)
- {
- for(i = 0; i < nImgWidth; i++)
- {
- destpCxImage.SetPixelRGB(i, j, sourpImgbuf[j][i],sourpImgbuf[j][i],sourpImgbuf[j][i]);
- }
- }
- return TRUE;
- }
- //24位真彩色
- //CImage转换成MYCOLORIMAGE
- BOOL CxxImageToMYIMAGE(MYCOLORIMAGE destpImgbuf, CImage& sourpCxImage, int nImgWidth, int nImgHeight)
- {
- // 参数检查
- if(destpImgbuf.r == NULL || sourpCxImage == NULL || nImgWidth <= 0 || nImgHeight <= 0)
- return FALSE;
- int i, j;
- COLORREF rgb;
- //24位转换为24位存储
- for(j = 0; j < nImgHeight; j++)
- {
- for(i = 0; i < nImgWidth; i++)
- {
- rgb=sourpCxImage.GetPixel(i, j);
- destpImgbuf.r[j][i] = GetRValue(rgb);
- destpImgbuf.g[j][i] = GetGValue(rgb) ;
- destpImgbuf.b[j][i] = GetBValue(rgb) ;
- }
- }
- return TRUE;
- }
- //MYCOLORIMAGE转换成CImage
- BOOL MYIMAGEToCxxImage(CImage& destpCxImage, MYCOLORIMAGE sourpImgbuf, int nImgWidth, int nImgHeight)
- {
- // 参数检查
- if(destpCxImage == NULL || sourpImgbuf.r == NULL || nImgWidth <= 0 || nImgHeight <= 0)
- return FALSE;
- int i, j;
- //24位转换为24位存储
- for(j = 0; j < nImgHeight; j++)
- {
- for(i = 0; i < nImgWidth; i++)
- {
- destpCxImage.SetPixelRGB(i, j,sourpImgbuf.r[j][i],sourpImgbuf.g[j][i],sourpImgbuf.b[j][i]);
- }
- }
- return TRUE;
- }
1、程序示例,一个Laplacian算子进行锐化的例子。
- //模版系数取1
- if (m_Image.IsNull())
- return;
- BeginWaitCursor();
- if (!m_Img.IsNull())
- m_Img.Destroy();
- m_Img.Create( m_Image.GetWidth(), m_Image.GetHeight(), 24,0);
- int nWidth = m_Image.GetWidth();
- int nHeight = m_Image.GetHeight();
- MYIMAGE RData=NULL;
- MYIMAGE GData=NULL;
- MYIMAGE BData=NULL;
- RData=MyImageAlloc(nHeight,nWidth);
- GData=MyImageAlloc(nHeight,nWidth);
- BData=MyImageAlloc(nHeight,nWidth);
- COLORREF color ;
- for(int j = 0;j<nWidth;j++)
- for(int i = 0;i<nHeight; i++)
- {
- color = m_Image.GetPixel(j,i);
- RData[i][j]= GetRValue(color);
- GData[i][j]= GetGValue(color);
- BData[i][j]= GetBValue(color);
- }
- int templ[9] = {0,-1,0,-1,4,-1,0,-1,0};
- for (int i = 1; i < nWidth-1; i++)
- {
- for (int j = 1; j < nHeight-1; j++)
- {
- int r = 0, g= 0, b = 0;
- int index = 0;
- //模版1
- for (int col = -1; col <= 1; col++)
- {
- for (int row = -1; row <= 1; row++)
- {
- r+= RData[j+row][i+col] * templ[index];
- g+= GData[j+row][i+col] * templ[index];
- b+= BData[j+row][i+col] * templ[index];
- index++;
- }
- }
- if ( r < 0 ) r = -r;
- else if ( r > 255 ) r = 255;
- if ( g < 0 ) g = -g;
- else if ( g > 255 ) g = 255;
- if ( b < 0 ) b = -b;
- else if ( b > 255 ) b = 255;
- m_Img.SetPixelRGB(i,j,r,g,b);
- }
- }
- MyImageFree(RData, nHeight);
- MyImageFree(GData, nHeight);
- MyImageFree(BData, nHeight);
- Invalidate();
- EndWaitCursor();
2、比较:比较方便也比较快