《学习OpenCV》课后习题解答7

浅浅的花香味﹌ 2022-07-24 11:25 149阅读 0赞

题目：（P105）  
创建一个结构，结构中包含一个整数，一个CvPoint和一个 CvRect；称结构体为“my\_struct”。  
a. 写两个函数：void Write\_my\_strct(CvFileStorage\* fs, const char \* name, my\_struct\* ms) 和 void read\_my\_struct(CvFileStorage\* fs, CvFileNode\* ms\_node, my\_struct\* ms)  
b. 创建一个元素为my\_struct结构体且长度为10的数组，并将数组写入磁盘和从磁盘读入内存。

解答：

#include<cv.h>
    #include<highgui.h>
    
    typedef struct my_struct {
        int integer;
        CvPoint ptr;
        CvRect rect;
    }my_struct;
    
    void write_my_struct(CvFileStorage* fs, const char* name, my_struct* ms) {
        cvWriteInt(fs, "integer", ms[0].integer);
    
        cvStartWriteStruct(fs, "ptr", CV_NODE_SEQ);
        cvWriteInt(fs, NULL, ms[0].ptr.x);
        cvWriteInt(fs, NULL, ms[0].ptr.y);
        cvEndWriteStruct(fs);
    
        cvStartWriteStruct(fs, "rect", CV_NODE_SEQ);
        cvWriteInt(fs, NULL, ms[0].rect.x);
        cvWriteInt(fs, NULL, ms[0].rect.y);
        cvWriteInt(fs, NULL, ms[0].rect.width);
        cvWriteInt(fs, NULL, ms[0].rect.height);
        cvEndWriteStruct(fs);
    }
    
    void read_my_struct(CvFileStorage* fs, CvFileNode* ms_node, my_struct* ms) {
        int integer = cvReadIntByName(fs, NULL, "integer", 5);
        CvSeq* seq = cvGetFileNodeByName(fs, NULL, "ptr")->data.seq;
        int ptr_x = cvReadInt((CvFileNode*)cvGetSeqElem(seq, 0));
        int ptr_y = cvReadInt((CvFileNode*)cvGetSeqElem(seq, 1));
        seq = cvGetFileNodeByName(fs, NULL, "rect")->data.seq;
        int rect_x = cvReadInt((CvFileNode*)cvGetSeqElem(seq, 0));
        int rect_y = cvReadInt((CvFileNode*)cvGetSeqElem(seq, 1));
        int rect_width = cvReadInt((CvFileNode*)cvGetSeqElem(seq, 2));
        int rect_height = cvReadInt((CvFileNode*)cvGetSeqElem(seq, 3));
        CvPoint ptr = cvPoint(ptr_x, ptr_y);
        CvRect rect = cvRect(rect_x, rect_y, rect_width, rect_height);
        ms->integer = integer;
        ms->ptr.x = ptr_x;
        ms->ptr.y = ptr_y;
        ms->rect.x = rect_x;
        ms->rect.y = rect_y;
        ms->rect.width = rect_width;
        ms->rect.height = rect_height;
    }
    
    int main(int argc, char** argv) {
        my_struct ms[10] = { { 10, cvPoint(5, 5), cvRect(5, 5, 10, 10) } };
        CvFileStorage* sfs = cvOpenFileStorage("E:\\cfg.xml", NULL, CV_STORAGE_WRITE);
        write_my_struct(sfs, "struct", ms);
        cvReleaseFileStorage(&sfs);
    
        my_struct* ms2 = (my_struct*)malloc(sizeof(my_struct));
        CvFileStorage* ofs = cvOpenFileStorage("E:\\cfg.xml", NULL, CV_STORAGE_READ);
        read_my_struct(ofs, NULL, ms2);
        cvReleaseFileStorage(&ofs);
    
        printf("integer: %d\n", ms2->integer);
        printf("ptr: (%d, %d) \n", ms->ptr.x, ms->ptr.y);
        printf("rect: (%d, %d, %d, %d) \n", ms->rect.x, ms->rect.y, ms->rect.width, ms->rect.height);
        getchar();
        return 0;
    }