icvConvertToFastHaarFeature

/*
*icvConvertToFastHaarFeature
*作用：将haar特征转化为快速haar特征
 */
void icvConvertToFastHaarFeature( CvTHaarFeature* haarFeature，       //输入数组
CvFastHaarFeature* fastHaarFeature, //输出数组
int size,                           //size表示数组的大小
int step )                          //step表示积分图的row step，一步可以是8位，比如灰度图；一步也可以是24位，比如RGB图
{
int i = 0;//表示特征的个数
int j = 0;//表示一个特征里小矩形的个数

for( i = 0; i < size; i++ )
{
fastHaarFeature[i].tilted = haarFeature[i].tilted;
if( !fastHaarFeature[i].tilted )//当为直立特征
{
for( j = 0; j < CV_HAAR_FEATURE_MAX; j++ )
{
fastHaarFeature[i].rect[j].weight = haarFeature[i].rect[j].weight;
if( fastHaarFeature[i].rect[j].weight == 0.0F )
{
break;
}
//下面是利用宏的定义把普通的特征转化为能快速计算的haar特征
 CV_SUM_OFFSETS( fastHaarFeature[i].rect[j].p0,
fastHaarFeature[i].rect[j].p1,
fastHaarFeature[i].rect[j].p2,
fastHaarFeature[i].rect[j].p3,
haarFeature[i].rect[j].r, step )
}

}
else               //当为旋转特征时
{
for( j = 0; j < CV_HAAR_FEATURE_MAX; j++ )
{
fastHaarFeature[i].rect[j].weight = haarFeature[i].rect[j].weight;
if( fastHaarFeature[i].rect[j].weight == 0.0F )
{
break;
}
<pre name="code" class="cpp"> CV_TILTED_OFFSETS( fastHaarFeature[i].rect[j].p0, fastHaarFeature[i].rect[j].p1,
 fastHaarFeature[i].rect[j].p2, fastHaarFeature[i].rect[j].p3, haarFeature[i].rect[j].r, step )
 }
 }
 }
}

/*
* get sum image offsets for <rect> corner points
* step - row step (measured in image pixels!) of sum image
*/
//CV_SUM_OFFSETS( p0, p1, p2, p3, rect, step )表示一个垂直矩形的四个顶点，其中，以左上角的点为参考点
#define CV_SUM_OFFSETS( p0, p1, p2, p3, rect, step )                      \
/* (x, y) */                                                          \
(p0) = (rect).x + (step) * (rect).y;                                  \
/* (x + w, y) */                                                      \
(p1) = (rect).x + (rect).width + (step) * (rect).y;                   \
/* (x + w, y) */                                                      \
(p2) = (rect).x + (step) * ((rect).y + (rect).height);                \
/* (x + w, y + h) */                                                  \
(p3) = (rect).x + (rect).width + (step) * ((rect).y + (rect).height);

/*
* get tilted image offsets for <rect> corner points
* step - row step (measured in image pixels!) of tilted image
*/
//CV_TILTED_OFFSETS( p0, p1, p2, p3, rect, step ) 表示一个旋转45度矩形的四个顶点，其中以最上面那个点为参考点（x，y）
#define CV_TILTED_OFFSETS( p0, p1, p2, p3, rect, step )                   \
/* (x, y) */                                                          \
(p0) = (rect).x + (step) * (rect).y;                                  \
/* (x - h, y + h) */                                                  \
(p1) = (rect).x - (rect).height + (step) * ((rect).y + (rect).height);\
/* (x + w, y + w) */                                                  \
(p2) = (rect).x + (rect).width + (step) * ((rect).y + (rect).width);  \
/* (x + w - h, y + w + h) */                                          \
(p3) = (rect).x + (rect).width - (rect).height                        \
+ (step) * ((rect).y + (rect).width + (rect).height);