tempMat2.at<double>(2, 0)
时间: 2024-05-25 07:19:06 浏览: 18
As an AI language model, I do not have access to the specific value of tempMat2.at<double>(2, 0) as it is dependent on the specific values of the matrix tempMat2. However, in general, this line of code is accessing the value in the third row (index 2) and first column (index 0) of a matrix of double precision floating point numbers.
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s /= tempMat.at<double>(2, 0);
This line of code divides the scalar variable s by the value of the element at row 2 and column 0 in the matrix tempMat, which is presumably a double precision floating point value. This operation effectively scales down the value of s based on the distance between the detected object and the camera, which is represented by the third coordinate (z-axis) in the homogeneous coordinate system. This scaling factor is necessary to convert the homogeneous coordinates to Euclidean coordinates, which have a meaningful physical interpretation.
birdview_points.at<double>(0, cols * i + j)
`birdview_points.at<double>(0, cols * i + j)` 是用来访问 `birdview_points` 矩阵中第一行第 `cols * i + j` 列位置上的元素。由于矩阵 `birdview_points` 中的数据类型为双精度浮点数,因此使用 `at<double>(...)` 函数来访问和修改矩阵中的元素。
具体来说,`at<double>(0, cols * i + j)` 返回 `birdview_points` 矩阵中第一行第 `cols * i + j` 列位置上的元素,并且该元素的数据类型为双精度浮点数。相应地,`at<double>(1, cols * i + j)` 和 `at<double>(2, cols * i + j)` 分别用于访问矩阵中的第二行和第三行的元素。这三行元素分别表示鸟瞰图坐标系下的 x、y、z 三个坐标轴上的坐标。