app.py

import gradio as gr
from PIL import Image
import torchvision
from torchvision import transforms
import torch
import matplotlib.pyplot as plt
import numpy as np
from models.modelNetA import Generator as GA
from models.modelNetB import Generator as GB
from models.modelNetC import Generator as GC

# load model
modeltype2path = {
    'ModelA': 'DTM_exp_train10%_model_a/g-best.pth',
    'ModelB': 'DTM_exp_train10%_model_b/g-best.pth',
    'ModelC': 'DTM_exp_train10%_model_c/g-best.pth',
}
DEVICE='cpu'
MODELS_TYPE = list(modeltype2path.keys())
generators = [GA(), GB(), GC()]

for i in range(len(generators)):
    generators[i] = torch.nn.DataParallel(generators[i])
    state_dict = torch.load(modeltype2path[MODELS_TYPE[i]], map_location=torch.device('cpu'))
    generators[i].load_state_dict(state_dict)
    generators[i] = generators[i].module.to(DEVICE)
    generators[i].eval()

preprocess = transforms.Compose([
    transforms.Grayscale(),
    transforms.ToTensor()
])

def predict(input_image, model_name):
    pil_image = Image.fromarray(input_image.astype('uint8'), 'RGB')
    # transform image to torch and do preprocessing
    torch_img = preprocess(pil_image).to(DEVICE).unsqueeze(0).to(DEVICE)
    # model predict
    with torch.no_grad():
        output = generators[MODELS_TYPE.index(model_name)](torch_img)
    sr, sr_dem_selected = output[0], output[1]
    # transform torch to image
    sr = sr.squeeze(0).cpu()
    torchvision.utils.save_image(sr, 'sr_pred.png')
    sr = np.array(Image.open('sr_pred.png'))

    sr_dem_selected = sr_dem_selected.squeeze().cpu().detach().numpy()
    fig, ax = plt.subplots()
    im = ax.imshow(sr_dem_selected, cmap='jet', vmin=0, vmax=np.max(sr_dem_selected))
    plt.colorbar(im, ax=ax)
    fig.canvas.draw()
    data = np.frombuffer(fig.canvas.tostring_rgb(), dtype=np.uint8)
    data = data.reshape(fig.canvas.get_width_height()[::-1] + (3,))
    # return correct image
    return sr, data

iface = gr.Interface(
    fn=predict, 
    inputs=[
        gr.Image(shape=(512,512)),
         gr.inputs.Radio(MODELS_TYPE)
    ], 
    outputs=[
        gr.Image(),
        gr.Image()
    ],
    examples=[
        ["demo_imgs/fake.jpg", MODELS_TYPE[0]] # use real image
    ],
    title="DTM Estimation",
    description="This demo predict a DTM..."
)
iface.launch()