c - 使用 OpenCV C API 计算 CvArr 中所有元素的总和

Question

使用 OpenCV 的基于C语言的 API，我需要计算 OpenCV 数组中所有元素的总和。我使用sum（1）方法。以下是我尝试过的。

/* rgb1 is an OpenCV array */
CvScalar cvSum( const CvArr* rgb1);
printf("%lf", CvScalar.val);

但我得到编译器错误为error: expected primary-expression before ‘.’ token.

Answer 1

'val' is an array of doubles. You need to access it via val[0], and printf it using %f

You also have a bug. What you wrote in not valid C code.
It should be this:

CvScalar sum = cvSum(rgb1);
printf("%f", sum.val[0]);

or if you don't want the variable:

printf("%f", cvSum(rgb1).val[0]);