How can i get the Trimaps of my pictures?

Now, I got a model, I want to use it but I can't, because I have not the Trimaps of my pictures. Are there the script of code to build the Trimaps? How can i get the Trimaps of my pictures?

The principle of the paper requires us to provide two pictures：images and the image's trimap

Get Trimap's code in here:

Deep-Image-Matting-PyTorch/data_gen.py

Line 87 in db6a96d

def gen_trimap(alpha):

But this function need we provide alpha image.
It seems we have to get it by ourself.
Obtained manually by PS or by semantic segmentation model

This is my personal view,I don't know if this is right.

你好，请问你是否能提供预训练模型以供参考？

It depends on trimaps.