从blob SQLite读取二进制图像并使用OpenCV imdecode解码它的最佳方法是什么?

时间:2015-09-12 19:30:28

标签: c++ sqlite opencv binary blob

我在C ++中存储和读取来自SQLite数据库的图像文件,存储工作正常,但我无法使用imdecode读取并将字节转换为OpenCV cv :: Mat。这是我的代码:

std::vector<cv::Mat> images;
std::vector<string> names;
std::vector<int> ids;

sqlite3 *db;
if (sqlite3_open("fr.db", &db) != SQLITE_OK)
{
    printf("Open database failed\n");
    return 0;
}

sqlite3_stmt *statement;
const char* sql = "SELECT * FROM Friends";
if (sqlite3_prepare_v2(db, sql, strlen(sql), &statement, 0) != SQLITE_OK)
{
    printf("Open database failed\n");
    return 0;
}

int result = 0;
while (true)
{
    result = sqlite3_step(statement);

    if (result == SQLITE_ROW)
    {
        int id = sqlite3_column_int(statement, 0);
        ids.push_back(id);

        int size = sqlite3_column_bytes(statement, 1);
        std::vector<byte> data((byte)sqlite3_column_blob(statement, 1), size);
        images.push_back(cv::imdecode(data, CV_LOAD_IMAGE_COLOR));

        char* name = (char*)sqlite3_column_text(statement, 2);
        names.push_back(name);
    }
    else
    {
        break;
    }
}

问题是imdecode没有构建cv :: Mat但它返回空的.. 提前谢谢。

0 个答案:

没有答案