C ++/SIFT/SQL-是否可以有效地比较图像的SIFT描述符和SQL数据库中的SIFT描述符? [英] C++/SIFT/SQL - If there a way to compare efficiently a SIFT descriptor of an image with a SIFT descriptor in a SQL database?

问题描述

我想找到一种方法，可以将图像(查询)的SIFT描述符与包含大量不同图片描述符的SQL数据库中的描述符进行比较.

I would like to find a way which would allow to compare a SIFT descriptor of an image (query) with descriptors in a SQL database which contains lots of descriptors of differents pictures.

实际上，我的最终目的是创建一个应用程序，该程序可以将一个图片与一个数据库(而不是我的设备中)但在一个SQL数据库中的很多图片进行比较.

In fact, my final purpose is to do an application which allow to compare one picture with lots of picture in a database (not in my device) but in a SQL database.

我想到的第一件事是将每个描述符存储在SQL数据库上，并使用蛮力方法或FlanneBased方法将每个描述符与另一个描述符进行比较.问题是，在SQL数据库中，由于匹配背后的数学"(例如，欧几里得距离为sqrt(a²+b²+ ...))，计算匹配要花费很长时间.在庞大的数据库中进行这种比较.

The first thing i thought was to stock each descriptors on the SQL database and compare each descriptors to another one using the Brute Force method or the FlanneBased method. The problem is that,in a SQL database, it would take a long time to compute a matching because of the "mathematics" behind the matching (Euclidean distance for example is sqrt(a²+b² +...) ) and it's not possible to do that kind of comparison in an huge database.

例如，如果我没有记错的话，SIFT描述符包含128个数字，那么想象一下将每个描述符的每个数字都比较在一起的时间.

For example a SIFT descriptor contains 128 numbers if i'm not mistaken so imagine the time comparing each number of each descriptors together.

如果还有另一种方法可以做到这一点?我知道在SQL数据库中，当您使用"SELECT a FROM b WHERE ..."之类的请求时，请求是有效的.

If there another way to do that stuff ? I know in a SQL database, requests are efficient when you use something like "SELECT a FROM b WHERE ..."

因此，我想知道是否存在一种有效存储SIFT描述符的方法?例如，我考虑过将描述符加密"成一条大的字符串链，并且每个链都是唯一的，因此我可以将它们进行比较，但我不知道这是否是一个好的解决方案.

Therefore i wonder if there is a way to stock SIFT descriptors in an efficiently way ? For example i thought about "to crypte" the descriptors into a kind of big string chain and each chain would be unique and therefore i could compare them together but i don't know if it's a good solution.

我已经阅读了这篇文章:比较存储在SIFT中的功能一个mysql数据库，但是对我没有帮助. 谢谢.

I've already read this post : Comparing SIFT features stored in a mysql database but it didn't help me. Thank you.

推荐答案

如果您是我，我宁愿比较代码中的描述符，而不是SQL中的描述符. SQL并非用于此目的.我将执行以下操作:-

If I were you, I would prefer comparing the descriptors in the code, rather than in SQL. SQL isn't meant for that. I would do the following:-

1. Pre-load N descriptors from SQL onto memory.
2. Compare distances to query descriptor, descriptor by descriptor.
3. If distance<threshold, push to possiblematches.
4. When you reach N/2 descriptors, push the next N.
5. Compare all matches, choose the best one or the best D descriptors, as per your requirement.

但是，为此，我宁愿使用OpenCV的内置FileStorage类，该类为XML和YAML文件提供I/O.它解决了手动解析描述符值的麻烦.

However, for this, I'd rather use OpenCV¡s inbuilt FileStorage class which provides I/O onto XML and YAML files; it solves the headache of manually parsing descriptor values.

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