icvCreateIntHaarFeatures超详细解析（不看你会后悔的）

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/* * icvCreateIntHaarFeatures * * Create internal representation of haar features * * mode: *  0 - BASIC = Viola *  1 - CORE  = All upright *  2 - ALL   = All features *///功能：针对大小为winsize的图像，计算所有的HaarFeature的rect,并存入features 返回输入staticCvIntHaarFeatures* icvCreateIntHaarFeatures( CvSize winsize,                                             int mode, /*   mode=0，只计算如下6种特征haar_x2,haar_y2,haar_x3,haar_y3,haar_y4,haar_x2_y2       mode=1,只计算如下8种特征haar_x2,haar_y2,haar_x3,haar_y3,haar_x4,haar_y4,haar_point       mode=2,计算所以特征，如下：haar_x2,haar_y2,haar_x3,haar_y3,haar_x4,haar_y4,haar_point，tilted_haar_x2，tilted_haar_y2，                                  tilted_haar_x3，tilted_haar_y3，tilted_haar_x4，tilted_haar_y4。*/                                             int symmetric )/*表示目标图形是否为垂直对称.Symmetric 为 1 表示只创建 Haar 特征的中心在左半部分的所有特征，为 0 时创建所有特征。当训练人脸图像时，由于人脸的左右对称性可以设置 Symmetric 为 1，以加速训练。 */{    CvIntHaarFeatures* features = NULL;//存储所有Haar特征的结构体，Haar特征由指针CvTHaarFeature所指向。    CvTHaarFeature haarFeature;        //一个Haar特征由2到3个具有相应权重的矩形组成。                                       //这几个矩形的权重符号相反，并且权重的绝对值跟矩形的大小成反比。/*内存存储器是一个可用来存储诸如序列,轮廓,图形,子划分等动态增长数据结构的底层结构。它是由一系列以同等大小的内存块构成,呈列表型，本句选自https://code.csdn.net/snippets/632568/master/.cpp/raw*/    CvMemStorage* storage = NULL;    CvSeq* seq = NULL;    CvSeqWriter writer;    int s0 = 36; /* minimum total area size of basic haar feature     */    int s1 = 12; /* minimum total area size of tilted haar features 2 */    int s2 = 18; /* minimum total area size of tilted haar features 3 */    int s3 = 24; /* minimum total area size of tilted haar features 4 */    int x  = 0;    int y  = 0;    //(x,y)表示小矩形的位置    int dx = 0;    //dx表示小矩形的宽    int dy = 0;    //dy表示小矩形的高/////////////////////////////////////////////////////////////////////////////////计算缩放因子factor//winsize是训练样本的大小#if 0    float factor = 1.0F;    factor = ((float) winsize.width) * winsize.height / (24 * 24);    s0 = (int) (s0 * factor);    s1 = (int) (s1 * factor);    s2 = (int) (s2 * factor);    s3 = (int) (s3 * factor);#else    s0 = 1;    s1 = 1;    s2 = 1;    s3 = 1;#endif    /* CV_VECTOR_CREATE( vec, CvIntHaarFeature, size, maxsize ) */    storage = cvCreateMemStorage();//功能：创建新序列，并初始化写入部分    cvStartWriteSeq( 0, sizeof( CvSeq ), sizeof( haarFeature ), storage, &writer );    for( x = 0; x < winsize.width; x++ )    {        for( y = 0; y < winsize.height; y++ )        {            for( dx = 1; dx <= winsize.width; dx++ )            {                for( dy = 1; dy <= winsize.height; dy++ )                {                    // haar_x2                    if ( (x+dx*2 <= winsize.width) && (y+dy <= winsize.height) ) {                        if (dx*2*dy < s0) continue;///?????????????????????                        if (!symmetric || (x+x+dx*2 <=winsize.width)) {                            haarFeature = cvHaarFeature( "haar_x2",//类型                                x,    y, dx*2, dy, -1,             //[x,y,dx*2,dy]是一个小矩形左上角的位置和高和宽，-1是其权重                                x+dx, y, dx  , dy, +2 );           //[x,y,dx*2,dy]是一个小矩形左上角的位置和高和宽，2是其权重             //第一个小矩形中的像素和乘以-1，然后加上第二个小矩形的像素和乘以2，也就是水平方向上两个等宽的小矩形，用右边的减去左边的                            /* CV_VECTOR_PUSH( vec, CvIntHaarFeature, haarFeature, size, maxsize, step ) */                            CV_WRITE_SEQ_ELEM( haarFeature, writer );                        }                    }                    // haar_y2                    if ( (x+dx <= winsize.width) && (y+dy*2 <= winsize.height) ) {                        if (dx*2*dy < s0) continue;                        if (!symmetric || (x+x+dx <= winsize.width)) {                            haarFeature = cvHaarFeature( "haar_y2",                                x, y,    dx, dy*2, -1,                                x, y+dy, dx, dy,   +2 );                            CV_WRITE_SEQ_ELEM( haarFeature, writer );                        }                    }                    // haar_x3                    if ( (x+dx*3 <= winsize.width) && (y+dy <= winsize.height) ) {                        if (dx*3*dy < s0) continue;                        if (!symmetric || (x+x+dx*3 <=winsize.width)) {                            haarFeature = cvHaarFeature( "haar_x3",                                x,    y, dx*3, dy, -1,                                x+dx, y, dx,   dy, +3 );                            CV_WRITE_SEQ_ELEM( haarFeature, writer );                        }                    }                    // haar_y3                    if ( (x+dx <= winsize.width) && (y+dy*3 <= winsize.height) ) {                        if (dx*3*dy < s0) continue;                        if (!symmetric || (x+x+dx <= winsize.width)) {                            haarFeature = cvHaarFeature( "haar_y3",                                x, y,    dx, dy*3, -1,                                x, y+dy, dx, dy,   +3 );                            CV_WRITE_SEQ_ELEM( haarFeature, writer );                        }                    }                    if( mode != 0 /*BASIC*/ ) {                        // haar_x4                        if ( (x+dx*4 <= winsize.width) && (y+dy <= winsize.height) ) {                            if (dx*4*dy < s0) continue;                            if (!symmetric || (x+x+dx*4 <=winsize.width)) {                                haarFeature = cvHaarFeature( "haar_x4",                                    x,    y, dx*4, dy, -1,                                    x+dx, y, dx*2, dy, +2 );                                CV_WRITE_SEQ_ELEM( haarFeature, writer );                            }                        }                        // haar_y4                        if ( (x+dx <= winsize.width ) && (y+dy*4 <= winsize.height) ) {                            if (dx*4*dy < s0) continue;                            if (!symmetric || (x+x+dx   <=winsize.width)) {                                haarFeature = cvHaarFeature( "haar_y4",                                    x, y,    dx, dy*4, -1,                                    x, y+dy, dx, dy*2, +2 );                                CV_WRITE_SEQ_ELEM( haarFeature, writer );                            }                        }                    }                    // x2_y2                    if ( (x+dx*2 <= winsize.width) && (y+dy*2 <= winsize.height) ) {                        if (dx*4*dy < s0) continue;                        if (!symmetric || (x+x+dx*2 <=winsize.width)) {                            haarFeature = cvHaarFeature( "haar_x2_y2",                                x   , y,    dx*2, dy*2, -1,                                x   , y   , dx  , dy,   +2,                                x+dx, y+dy, dx  , dy,   +2 );                            CV_WRITE_SEQ_ELEM( haarFeature, writer );                        }                    }                    if (mode != 0 /*BASIC*/) {                        // point                        if ( (x+dx*3 <= winsize.width) && (y+dy*3 <= winsize.height) ) {                            if (dx*9*dy < s0) continue;                            if (!symmetric || (x+x+dx*3 <=winsize.width))  {                                haarFeature = cvHaarFeature( "haar_point",//"haar_point"为3*3的小矩形                                    x   , y,    dx*3, dy*3, -1,                                    x+dx, y+dy, dx  , dy  , +9);                                CV_WRITE_SEQ_ELEM( haarFeature, writer );                            }                        }                    }                    if (mode == 2 /*ALL*/) {                        // tilted haar_x2                                      (x, y, w, h, b, weight)                        if ( (x+2*dx <= winsize.width) && (y+2*dx+dy <= winsize.height) && (x-dy>= 0) ) {                            if (dx*2*dy < s1) continue;                            if (!symmetric || (x <= (winsize.width / 2) )) {                                haarFeature = cvHaarFeature( "tilted_haar_x2",///??????????????????????????????                                    x, y, dx*2, dy, -1,                                    x, y, dx  , dy, +2 );                                CV_WRITE_SEQ_ELEM( haarFeature, writer );                            }                        }                        // tilted haar_y2                                      (x, y, w, h, b, weight)                        if ( (x+dx <= winsize.width) && (y+dx+2*dy <= winsize.height) && (x-2*dy>= 0) ) {                            if (dx*2*dy < s1) continue;                            if (!symmetric || (x <= (winsize.width / 2) )) {                                haarFeature = cvHaarFeature( "tilted_haar_y2",                                    x, y, dx, 2*dy, -1,                                    x, y, dx,   dy, +2 );                                CV_WRITE_SEQ_ELEM( haarFeature, writer );                            }                        }                        // tilted haar_x3                                   (x, y, w, h, b, weight)                        if ( (x+3*dx <= winsize.width) && (y+3*dx+dy <= winsize.height) && (x-dy>= 0) ) {                            if (dx*3*dy < s2) continue;                            if (!symmetric || (x <= (winsize.width / 2) )) {                                haarFeature = cvHaarFeature( "tilted_haar_x3",//////?????????????????????????                                    x,    y,    dx*3, dy, -1,                                    x+dx, y+dx, dx  , dy, +3 );                                CV_WRITE_SEQ_ELEM( haarFeature, writer );                            }                        }                        // tilted haar_y3                                      (x, y, w, h, b, weight)                        if ( (x+dx <= winsize.width) && (y+dx+3*dy <= winsize.height) && (x-3*dy>= 0) ) {                            if (dx*3*dy < s2) continue;                            if (!symmetric || (x <= (winsize.width / 2) )) {                                haarFeature = cvHaarFeature( "tilted_haar_y3",//????????????????????????                                    x,    y,    dx, 3*dy, -1,                                    x-dy, y+dy, dx,   dy, +3 );                                CV_WRITE_SEQ_ELEM( haarFeature, writer );                            }                        }                        // tilted haar_x4                                   (x, y, w, h, b, weight)                        if ( (x+4*dx <= winsize.width) && (y+4*dx+dy <= winsize.height) && (x-dy>= 0) ) {                            if (dx*4*dy < s3) continue;                            if (!symmetric || (x <= (winsize.width / 2) )) {                                haarFeature = cvHaarFeature( "tilted_haar_x4",//??????????????????????                                    x,    y,    dx*4, dy, -1,                                    x+dx, y+dx, dx*2, dy, +2 );                                CV_WRITE_SEQ_ELEM( haarFeature, writer );                            }                        }                        // tilted haar_y4                                      (x, y, w, h, b, weight)                        if ( (x+dx <= winsize.width) && (y+dx+4*dy <= winsize.height) && (x-4*dy>= 0) ) {                            if (dx*4*dy < s3) continue;                            if (!symmetric || (x <= (winsize.width / 2) )) {                                haarFeature = cvHaarFeature( "tilted_haar_y4",//????????????????                                    x,    y,    dx, 4*dy, -1,                                    x-dy, y+dy, dx, 2*dy, +2 );                                CV_WRITE_SEQ_ELEM( haarFeature, writer );                            }                        }                        /*                          // tilted point                          if ( (x+dx*3 <= winsize.width - 1) && (y+dy*3 <= winsize.height - 1) && (x-3*dy>= 0)) {                          if (dx*9*dy < 36) continue;                          if (!symmetric || (x <= (winsize.width / 2) ))  {                            haarFeature = cvHaarFeature( "tilted_haar_point",                                x, y,    dx*3, dy*3, -1,                                x, y+dy, dx  , dy,   +9 );                                CV_WRITE_SEQ_ELEM( haarFeature, writer );                          }                          }                        */                    }                }            }        }    }    seq = cvEndWriteSeq( &writer );//函数cvEndWriteSeq完成写入操作并返回指向被写入元素的序列的地址,                               //同时,函数将截取最后那个不完整的序列块.块的剩余部分返回到内存之后,序列即可以被安全地读和写.    features = (CvIntHaarFeatures*) cvAlloc( sizeof( CvIntHaarFeatures ) +        ( sizeof( CvTHaarFeature ) + sizeof( CvFastHaarFeature ) ) * seq->total );//opencv中所有的内存分配和释放都是通过cvAlloc和cvFree合作完成的.//如果cvAlloc/cvFree不是匹配出现, 那么可以认为出现了内存泄漏.    features->feature = (CvTHaarFeature*) (features + 1);    features->fastfeature = (CvFastHaarFeature*) ( features->feature + seq->total );    features->count = seq->total;    features->winsize = winsize;//复制序列的全部或部分到一个连续内存数组中；    cvCvtSeqToArray( seq, (CvArr*) features->feature );    cvReleaseMemStorage( &storage );//将普通的特征转化为快速计算的haar特征    icvConvertToFastHaarFeature( features->feature, features->fastfeature,                                 features->count, (winsize.width + 1) );    return features;}