utility.py

import os
import math
import time
import datetime
from multiprocessing import Process
from multiprocessing import Queue

import matplotlib
matplotlib.use('Agg')
import matplotlib.pyplot as plt

import numpy as np
import imageio

import torch
import torch.optim as optim
import torch.optim.lr_scheduler as lrs

class timer():
    def __init__(self):
        self.acc = 0
        self.tic()

    def tic(self):
        self.t0 = time.time()

    def toc(self, restart=False):
        diff = time.time() - self.t0
        if restart: self.t0 = time.time()
        return diff

    def hold(self):
        self.acc += self.toc()

    def release(self):
        ret = self.acc
        self.acc = 0

        return ret

    def reset(self):
        self.acc = 0

class checkpoint():
    def __init__(self, args):
        self.args = args
        self.ok = True
        self.log = torch.Tensor()
        now = datetime.datetime.now().strftime('%Y-%m-%d-%H:%M:%S')

        if args.load == '.':
            if args.save == '.': args.save = now
            self.dir = '../experiment/' + args.save
        else:
            self.dir = '../experiment/' + args.load
            if not os.path.exists(self.dir):
                args.load = '.'
            else:
                self.log = torch.load(self.dir + '/psnr_log.pt')
                print('Continue from epoch {}...'.format(len(self.log)))

        if args.reset:
            os.system('rm -rf ' + self.dir)
            args.load = '.'

        def _make_dir(path):
            if not os.path.exists(path): os.makedirs(path)

        _make_dir(self.dir)
        _make_dir(self.get_path('model'))
        _make_dir(self.get_path('results'))

        open_type = 'a' if os.path.exists(self.get_path('log.txt'))else 'w'
        self.log_file = open(self.get_path('log.txt'), open_type)
        with open(self.get_path('config.txt'), open_type) as f:
            f.write(now + '\n\n')
            for arg in vars(args):
                f.write('{}: {}\n'.format(arg, getattr(args, arg)))
            f.write('\n')

        self.n_processes = 8

    def get_path(self, *subdir):
        return os.path.join(self.dir, *subdir)

    def save(self, trainer, epoch, is_best=False):
        trainer.model.save(self.get_path('model'), epoch, is_best=is_best)
        trainer.loss.save(self.dir)
        trainer.loss.plot_loss(self.dir, epoch)

        self.plot_psnr(epoch)
        torch.save(self.log, self.get_path('psnr_log.pt'))
        torch.save(
            trainer.optimizer.state_dict(),
            self.get_path('optimizer.pt')
        )

    def add_log(self, log):
        self.log = torch.cat([self.log, log])

    def write_log(self, log, refresh=False):
        print(log)
        self.log_file.write(log + '\n')
        if refresh:
            self.log_file.close()
            self.log_file = open(self.get_path('log.txt'), 'a')

    def done(self):
        self.log_file.close()

    def plot_psnr(self, epoch):
        axis = np.linspace(1, epoch, epoch)
        label = 'SR on {}'.format(self.args.data_test)
        fig = plt.figure()
        plt.title(label)
        for idx_scale, scale in enumerate(self.args.scale):
            plt.plot(
                axis,
                self.log[:, idx_scale].numpy(),
                label='Scale {}'.format(scale)
            )
        plt.legend()
        plt.xlabel('Epochs')
        plt.ylabel('PSNR')
        plt.grid(True)
        plt.savefig(self.get_path('test_{}.pdf'.format(self.args.data_test)))
        plt.close(fig)

    def begin_background(self):
        self.queue = Queue()

        def bg_target(queue):
            while True:
                if not queue.empty():
                    filename, tensor = queue.get()
                    if filename is None: break
                    imageio.imwrite(filename, tensor.numpy())
        
        self.process = [
            Process(target=bg_target, args=(self.queue,)) \
            for _ in range(self.n_processes)
        ]
        
        for p in self.process: p.start()

    def end_background(self):
        for _ in range(self.n_processes): self.queue.put((None, None))
        while not self.queue.empty(): time.sleep(1)
        for p in self.process: p.join()

    def save_results(self, filename, save_list, scale):
        filename = self.get_path('results', '{}_x{}_'.format(filename, scale))
        postfix = ('SR', 'LR', 'HR')
        for v, p in zip(save_list, postfix):
            normalized = v[0].mul(255 / self.args.rgb_range)
            tensor_cpu = normalized.byte().permute(1, 2, 0).cpu()
            self.queue.put(('{}{}.png'.format(filename, p), tensor_cpu))

def quantize(img, rgb_range):
    pixel_range = 255 / rgb_range
    return img.mul(pixel_range).clamp(0, 255).round().div(pixel_range)

def calc_psnr(sr, hr, scale, rgb_range, benchmark=False):
    diff = (sr - hr).data.div(rgb_range)
    if benchmark:
        shave = scale
        if diff.size(1) > 1:
            convert = diff.new(1, 3, 1, 1)
            convert[0, 0, 0, 0] = 65.738
            convert[0, 1, 0, 0] = 129.057
            convert[0, 2, 0, 0] = 25.064
            diff.mul_(convert).div_(256)
            diff = diff.sum(dim=1, keepdim=True)
    else:
        shave = scale + 6

    valid = diff[:, :, shave:-shave, shave:-shave]
    mse = valid.pow(2).mean()

    return -10 * math.log10(mse)

def make_optimizer(args, my_model):
    trainable = filter(lambda x: x.requires_grad, my_model.parameters())

    if args.optimizer == 'SGD':
        optimizer_function = optim.SGD
        kwargs = {'momentum': args.momentum}
    elif args.optimizer == 'ADAM':
        optimizer_function = optim.Adam
        kwargs = {
            'betas': (args.beta1, args.beta2),
            'eps': args.epsilon
        }
    elif args.optimizer == 'RMSprop':
        optimizer_function = optim.RMSprop
        kwargs = {'eps': args.epsilon}

    kwargs['lr'] = args.lr
    kwargs['weight_decay'] = args.weight_decay
    
    return optimizer_function(trainable, **kwargs)

def make_scheduler(args, my_optimizer):
    if args.decay_type == 'step':
        scheduler = lrs.StepLR(
            my_optimizer,
            step_size=args.lr_decay,
            gamma=args.gamma
        )
    elif args.decay_type.find('step') >= 0:
        milestones = args.decay_type.split('_')
        milestones.pop(0)
        milestones = list(map(lambda x: int(x), milestones))
        scheduler = lrs.MultiStepLR(
            my_optimizer,
            milestones=milestones,
            gamma=args.gamma
        )

    return scheduler