OpenCv SVM輸出文件格式

Question

我正在實現自己的SVM，而不是使用OpenCV的svm類。我希望我的SVM用於保存其輸出的XML文件，如果願意，可以在將來由OpenCV的SVM加載和使用。我應該爲此做些什麼？

簡而言之：OpenCV用來存儲SVM輸出的格式是什麼？

Answer 1

您可以關注OpenCV的CvSVM :: write函數。

int i, var_count = get_var_count(), df_count, class_count; 
const CvSVMDecisionFunc* df = decision_func; 

cvStartWriteStruct(fs, name, CV_NODE_MAP, CV_TYPE_NAME_ML_SVM); 

write_params(fs); 

cvWriteInt(fs, "var_all", var_all); 
cvWriteInt(fs, "var_count", var_count); 

class_count = class_labels ? class_labels->cols : 
       params.svm_type == CvSVM::ONE_CLASS ? 1 : 0; 

if(class_count) 
{ 
    cvWriteInt(fs, "class_count", class_count); 

    if(class_labels) 
     cvWrite(fs, "class_labels", class_labels); 

    if(class_weights) 
     cvWrite(fs, "class_weights", class_weights); 
} 

if(var_idx) 
    cvWrite(fs, "var_idx", var_idx); 

// write the joint collection of support vectors 
cvWriteInt(fs, "sv_total", sv_total); 
cvStartWriteStruct(fs, "support_vectors", CV_NODE_SEQ); 
for(i = 0; i < sv_total; i++) 
{ 
    cvStartWriteStruct(fs, 0, CV_NODE_SEQ + CV_NODE_FLOW); 
    cvWriteRawData(fs, sv[i], var_count, "f"); 
    cvEndWriteStruct(fs); 
} 

cvEndWriteStruct(fs); 

// write decision functions 
df_count = class_count > 1 ? class_count*(class_count-1)/2 : 1; 
df = decision_func; 

cvStartWriteStruct(fs, "decision_functions", CV_NODE_SEQ); 
for(i = 0; i < df_count; i++) 
{ 
    int sv_count = df[i].sv_count; 
    cvStartWriteStruct(fs, 0, CV_NODE_MAP); 
    cvWriteInt(fs, "sv_count", sv_count); 
    cvWriteReal(fs, "rho", df[i].rho); 
    cvStartWriteStruct(fs, "alpha", CV_NODE_SEQ+CV_NODE_FLOW); 
    cvWriteRawData(fs, df[i].alpha, df[i].sv_count, "d"); 
    cvEndWriteStruct(fs); 
    if(class_count > 1) 
    { 
     cvStartWriteStruct(fs, "index", CV_NODE_SEQ+CV_NODE_FLOW); 
     cvWriteRawData(fs, df[i].sv_index, df[i].sv_count, "i"); 
     cvEndWriteStruct(fs); 
    } 
    else 
     CV_ASSERT(sv_count == sv_total); 
    cvEndWriteStruct(fs); 
} 
cvEndWriteStruct(fs); 
cvEndWriteStruct(fs); 

這裏是如何創建一個CvFileStorage並將其保存到磁盤：

const char* filename = "/xxx/yyy/zzz"; 
const char* modelname = "svm"; 
CvFileStorage* fs = cvOpenFileStorage(filename, 0, CV_STORAGE_WRITE); 
if (fs) { 
    write(fs, modelname); 
} 
cvReleaseFileStorage(&fs); 

通過這樣做，你可以選擇將模型保存爲XML或YAML格式，並使用CvSVM :: read（）加載模型文件。希望這可以幫助。