How to convert RGB PIL image to numpy array with 3 channels?

Question

I am loading image with the following code

image = PIL.Image.open(file_path)
image = np.array(image)

It works, but the size of array appears to be (X, X, 4), i.e. it has 4 layers. I would like normal RGB layers. Is it possible?

UPDATE

I found that just removing 4th channel is unsufficcient. The following code was required:

image = PIL.Image.open(file_path)
image.thumbnail(resample_size)
image = image.convert("RGB")
image = np.asarray(image, dtype=np.float32) / 255
image = image[:, :, :3]

Why?

Answer 1

The fourth layer is the transparency value for image formats that support transparency, like PNG. If you remove the 4th value it'll be a correct RGB image without transparency.

EDIT:

Example:

>>> import PIL.Image
>>> image = PIL.Image.open('../test.png')
>>> import numpy as np
>>> image = np.array(image)
>>> image.shape
(381, 538, 4)
>>> image[...,:3].shape
(381, 538, 3)