图像处理算法基础（二）---线性变换和伽马变换

1.灰度线性变换：F(x)=a*f(x)+b

int IMGChange(IplImage *src,IplImage *dest, float slope,float intercept)
{
 if(NULL == src)
  return -1;

 if(src->nChannels!=1 || dest->nChannels!=1)
 {
  cout<<"It's not gray image!"<   return -1;
 }
 float gray = 0; 
 for(int i = 0;i < src->height;i++){ 
  for(int j = 0; j < src->width; j++){ 
 
   gray = (float)src->imageData[src->widthStep * i + j ];
   gray = slope*gray + intercept;
   dest->imageData[dest->widthStep * i + j ]=gray;
        } 
    } 
 return 0;
}

当slope=-1   intercept=255即为图像反转

2.伽马变换，s=c*（r）γ，可用于图像增强等预处理。

int IMGgammaChange(IplImage *src,IplImage *dest, double gamma,double comp)
{
 if(NULL == src)
  return -1;

 if(src->nChannels!=1 || dest->nChannels!=1)
 {
  cout<<"It's not gray image!"<   return -1;
 }
 double gray = 0; 
 for(int i = 0;i < src->height;i++){ 
  for(int j = 0; j < src->width; j++){ 
 
   gray = (double)src->imageData[src->widthStep * i + j ];
   gray =pow((gray+comp)/255.0,gamma)*255;
   dest->imageData[dest->widthStep * i + j ]=gray;
        } 
    } 
 return 0;
}