numpy操作：将绿色转换为红色(numpy operation: convert green to red)

numpy操作：将绿色转换为红色(numpy operation: convert green to red)

我有想要转换为红色的图像，以防有绿色。 如果有红色，我想保留它。

图像处于numpy数组中，如下所示：

x.shape（50,15,3）

在第一个实例中，我想取第三维（R和G）的前两个元素的最大值，并将相应的值设置为R（第一个元素）。 然后我想设置第三个维度零的第二个元素（G）。

我怎样才能做到这一点？ 基本上它需要是这样的：

x[:,:,0] = max(x[:,:,0],x[:,:,1]) x[:,:,1] = 0

I have images that I would like to convert to red in case there is any green. If there's red, I'd like to keep it.

The images are in numpy arrays as follows:

x.shape (50, 15, 3)

In a fist instance I would like to take the max value of the first two elements of the third dimension (R and G) and set the corresponding value to R (the first element). Then I would like to set the second element (G) of the third dimension zo zero.

How can I do this? Essentially it woul need to be something like that:

x[:,:,0] = max(x[:,:,0],x[:,:,1]) x[:,:,1] = 0

最满意答案

看来你已经想出了第二步。 这是迈出第一步的一种方法 -

x[...,0] = x[...,:2].max(axis=-1)

或者，我们也可以使用np.maximum进行元素方式的最大计算 -

x[...,0] = np.maximum(x[...,0], x[...,1])

或者，我们也可以使用masking -

mask = x[...,0] < x[...,1] x[mask,0] = x[mask,1]

It seems you have already figured out the second step. Here's one way to do the first step -

x[...,0] = x[...,:2].max(axis=-1)

Alternatively, we can also use np.maximum for the element-wise max computation -

x[...,0] = np.maximum(x[...,0], x[...,1])

Alternatively, we can also use masking -

mask = x[...,0] < x[...,1] x[mask,0] = x[mask,1]