encoder.py

import argparse

import numpy as np
from scipy.misc import imread, imresize, imsave

import torch
from torch.autograd import Variable

parser = argparse.ArgumentParser()
parser.add_argument(
    '--model', '-m', required=True, type=str, help='path to model')
parser.add_argument(
    '--input', '-i', required=True, type=str, help='input image')
parser.add_argument(
    '--output', '-o', required=True, type=str, help='output codes')
parser.add_argument('--cuda', '-g', action='store_true', help='enables cuda')
parser.add_argument(
    '--iterations', type=int, default=16, help='unroll iterations')
args = parser.parse_args()

image = imread(args.input, mode='RGB')
image = torch.from_numpy(
    np.expand_dims(
        np.transpose(image.astype(np.float32) / 255.0, (2, 0, 1)), 0))
batch_size, input_channels, height, width = image.size()
assert height % 32 == 0 and width % 32 == 0

image = Variable(image, volatile=True)

import network

encoder = network.EncoderCell()
binarizer = network.Binarizer()
decoder = network.DecoderCell()

encoder.eval()
binarizer.eval()
decoder.eval()

encoder.load_state_dict(torch.load(args.model))
binarizer.load_state_dict(
    torch.load(args.model.replace('encoder', 'binarizer')))
decoder.load_state_dict(torch.load(args.model.replace('encoder', 'decoder')))

encoder_h_1 = (Variable(
    torch.zeros(batch_size, 256, height // 4, width // 4), volatile=True),
               Variable(
                   torch.zeros(batch_size, 256, height // 4, width // 4),
                   volatile=True))
encoder_h_2 = (Variable(
    torch.zeros(batch_size, 512, height // 8, width // 8), volatile=True),
               Variable(
                   torch.zeros(batch_size, 512, height // 8, width // 8),
                   volatile=True))
encoder_h_3 = (Variable(
    torch.zeros(batch_size, 512, height // 16, width // 16), volatile=True),
               Variable(
                   torch.zeros(batch_size, 512, height // 16, width // 16),
                   volatile=True))

decoder_h_1 = (Variable(
    torch.zeros(batch_size, 512, height // 16, width // 16), volatile=True),
               Variable(
                   torch.zeros(batch_size, 512, height // 16, width // 16),
                   volatile=True))
decoder_h_2 = (Variable(
    torch.zeros(batch_size, 512, height // 8, width // 8), volatile=True),
               Variable(
                   torch.zeros(batch_size, 512, height // 8, width // 8),
                   volatile=True))
decoder_h_3 = (Variable(
    torch.zeros(batch_size, 256, height // 4, width // 4), volatile=True),
               Variable(
                   torch.zeros(batch_size, 256, height // 4, width // 4),
                   volatile=True))
decoder_h_4 = (Variable(
    torch.zeros(batch_size, 128, height // 2, width // 2), volatile=True),
               Variable(
                   torch.zeros(batch_size, 128, height // 2, width // 2),
                   volatile=True))

if args.cuda:
    encoder = encoder.cuda()
    binarizer = binarizer.cuda()
    decoder = decoder.cuda()

    image = image.cuda()

    encoder_h_1 = (encoder_h_1[0].cuda(), encoder_h_1[1].cuda())
    encoder_h_2 = (encoder_h_2[0].cuda(), encoder_h_2[1].cuda())
    encoder_h_3 = (encoder_h_3[0].cuda(), encoder_h_3[1].cuda())

    decoder_h_1 = (decoder_h_1[0].cuda(), decoder_h_1[1].cuda())
    decoder_h_2 = (decoder_h_2[0].cuda(), decoder_h_2[1].cuda())
    decoder_h_3 = (decoder_h_3[0].cuda(), decoder_h_3[1].cuda())
    decoder_h_4 = (decoder_h_4[0].cuda(), decoder_h_4[1].cuda())

codes = []
res = image - 0.5
for iters in range(args.iterations):
    encoded, encoder_h_1, encoder_h_2, encoder_h_3 = encoder(
        res, encoder_h_1, encoder_h_2, encoder_h_3)

    code = binarizer(encoded)

    output, decoder_h_1, decoder_h_2, decoder_h_3, decoder_h_4 = decoder(
        code, decoder_h_1, decoder_h_2, decoder_h_3, decoder_h_4)

    res = res - output
    codes.append(code.data.cpu().numpy())

    print('Iter: {:02d}; Loss: {:.06f}'.format(iters, res.data.abs().mean()))

codes = (np.stack(codes).astype(np.int8) + 1) // 2

export = np.packbits(codes.reshape(-1))

np.savez_compressed(args.output, shape=codes.shape, codes=export)