def draw_concat(Gs, Zs, reals, NoiseAmp, in_s, mode, m_noise, m_image, opt,
                index_image, cuda_device):

    G_z = in_s

    if len(Gs) > 0:
        if mode == 'rand':
            count = 0
            pad_noise = int(((opt.ker_size - 1) * opt.num_layer) / 2)
            for scale_idx, (G) in enumerate(Gs):

                Z_opt = torch.cat([Zs[idx][scale_idx] for idx in index_image],
                                  dim=0)
                real_curr = torch.cat(
                    [reals[idx][scale_idx] for idx in index_image], dim=0)
                real_next = torch.cat(
                    [reals[idx][1:][scale_idx] for idx in index_image], dim=0)
                noise_amp = torch.cat(
                    ([NoiseAmp[id][scale_idx]
                      for id in range(opt.num_images)]),
                    dim=0).to(cuda_device)

                if count == 0:
                    z = functions.generate_noise([
                        1, Z_opt.shape[2] - 2 * pad_noise,
                        Z_opt.shape[3] - 2 * pad_noise
                    ],
                                                 device=cuda_device,
                                                 num_samp=real_curr.shape[0])
                    z = z.expand(real_curr.shape[0], 3, z.shape[2], z.shape[3])
                else:
                    z = functions.generate_noise([
                        opt.nc_z, Z_opt.shape[2] - 2 * pad_noise,
                        Z_opt.shape[3] - 2 * pad_noise
                    ],
                                                 device=cuda_device,
                                                 num_samp=real_curr.shape[0])

                noise_amp_tensor = torch.full(
                    [1, z.shape[1], z.shape[2], z.shape[3]],
                    noise_amp[0][0].item(),
                    dtype=torch.float).to(cuda_device)

                for i in range(1, opt.num_images):
                    temp = torch.full([1, z.shape[1], z.shape[2], z.shape[3]],
                                      noise_amp[i][0].item(),
                                      dtype=torch.float).to(cuda_device)
                    noise_amp_tensor = torch.cat((noise_amp_tensor, temp),
                                                 dim=0)

                z = m_noise(z)
                G_z = G_z[:, :, 0:real_curr.shape[2], 0:real_curr.shape[3]]
                G_z = m_image(G_z)

                z_in = m_noise(noise_amp_tensor) * z + G_z
                padded_id_z_in = pad_image_id(z_in, index_image)

                G_z_temp = G(padded_id_z_in.detach(), G_z)
                if isinstance(G_z_temp, list):

                    G_z_temp = [tens.to(cuda_device) for tens in G_z_temp]
                    G_z_temp = torch.cat(G_z_temp)
                G_z = imresize(torch.unsqueeze(G_z_temp[0], dim=0),
                               1 / opt.scale_factor, opt)
                for id in range(1, opt.num_images):
                    G_z = torch.cat(
                        (G_z,
                         imresize(torch.unsqueeze(G_z_temp[id], dim=0),
                                  1 / opt.scale_factor, opt)),
                        dim=0)

                G_z = G_z[:, :, 0:real_next.shape[2], 0:real_next.shape[3]]

                count += 1

        if mode == 'rec':
            count = 0

            for scale_idx, (G) in enumerate((Gs)):

                Z_opt = torch.cat([Zs[idx][scale_idx] for idx in index_image],
                                  dim=0)
                real_curr = torch.cat(
                    [reals[idx][scale_idx] for idx in index_image], dim=0)
                real_next = torch.cat(
                    [reals[idx][1:][scale_idx] for idx in index_image], dim=0)
                noise_amp = torch.cat(
                    ([NoiseAmp[id][scale_idx]
                      for id in range(opt.num_images)]),
                    dim=0).to(cuda_device)

                noise_amp_tensor = torch.full(
                    [1, Z_opt.shape[1], Z_opt.shape[2], Z_opt.shape[3]],
                    noise_amp[0][0].item(),
                    dtype=torch.float).to(cuda_device)
                for i in range(1, opt.num_images):
                    temp = torch.full(
                        [1, Z_opt.shape[1], Z_opt.shape[2], Z_opt.shape[3]],
                        noise_amp[i][0].item(),
                        dtype=torch.float).to(cuda_device)
                    noise_amp_tensor = torch.cat((noise_amp_tensor, temp),
                                                 dim=0)

                G_z = G_z[:, :, 0:real_curr.shape[2], 0:real_curr.shape[3]]
                G_z = m_image(G_z)
                z_in = noise_amp_tensor * Z_opt + G_z

                padded_id_z_in = pad_image_id(z_in, index_image)
                G_z_temp = G(padded_id_z_in.detach(), G_z)
                if isinstance(G_z_temp, list):
                    G_z_temp = [tens.to(cuda_device) for tens in G_z_temp]
                    G_z_temp = torch.cat(G_z_temp)
                G_z = imresize(torch.unsqueeze(G_z_temp[0], dim=0),
                               1 / opt.scale_factor, opt)

                for id in range(1, opt.num_images):
                    G_z = torch.cat(
                        (G_z,
                         imresize(torch.unsqueeze(G_z_temp[id], dim=0),
                                  1 / opt.scale_factor, opt)),
                        dim=0)

                G_z = G_z[:, :, 0:real_next.shape[2], 0:real_next.shape[3]]
                count += 1

    return G_z
def train(opt, Gs, Zs, reals, NoiseAmp):
    reals, Zs, NoiseAmp, in_s, scale_num = functions.collect_reals(
        opt, reals, Zs, NoiseAmp)
    nfc_prev = 0
    for index_image in range(int(opt.num_images)):
        NoiseAmp[index_image] = []

    while scale_num < opt.stop_scale + 1:

        opt.nfc = min(opt.nfc_init * pow(2, math.floor(scale_num / 4)),
                      opt.size_image)
        opt.min_nfc = min(opt.min_nfc_init * pow(2, math.floor(scale_num / 4)),
                          opt.size_image)
        D_curr, G_curr = init_models(opt)

        index_arr_flag = 0

        for epoch in range(opt.num_epochs):

            optimizerD = optim.Adam(D_curr.parameters(),
                                    lr=opt.lr_d,
                                    betas=(opt.beta1, 0.999))
            optimizerG = optim.Adam(G_curr.parameters(),
                                    lr=opt.lr_g,
                                    betas=(opt.beta1, 0.999))
            schedulerD = torch.optim.lr_scheduler.MultiStepLR(
                optimizer=optimizerD, milestones=[500], gamma=opt.gamma)
            schedulerG = torch.optim.lr_scheduler.MultiStepLR(
                optimizer=optimizerG, milestones=[1000], gamma=opt.gamma)

            print(" ")
            print("this is class: ", opt.pos_class)
            print("size image: ", opt.size_image)
            print("num images: ", opt.num_images)
            print("index of download: ", opt.index_download)
            print("num transforms: ", opt.num_transforms)
            print(" ")

            index_image = range(int(opt.num_images))
            G_curr = functions.reset_grads(G_curr, True)
            D_curr = functions.reset_grads(D_curr, True)

            opt.out_ = functions.generate_dir2save(opt)
            opt.global_outf = '%s/%d' % (opt.out_, scale_num)
            if os.path.exists(opt.global_outf):
                shutil.rmtree(opt.global_outf)
            opt.outf = [
                '%s/%d/index_image_%d' % (opt.out_, scale_num, id)
                for id in index_image
            ]
            try:
                for j in opt.outf:
                    try:
                        os.makedirs(j)
                    except:
                        pass
            except OSError as err:
                print("OS error: {0}".format(err))
                pass

            for id in index_image:
                plt.imsave('%s/real_scale%d.png' % (opt.outf[id], id),
                           functions.convert_image_np(reals[id][scale_num]),
                           vmin=0,
                           vmax=1)
            if (nfc_prev == opt.nfc):
                G_curr.load_state_dict(
                    torch.load('%s/%d/netG.pth' % (opt.out_, scale_num - 1)))
                D_curr.load_state_dict(
                    torch.load('%s/%d/netD.pth' % (opt.out_, scale_num - 1)))
                nfc_prev = 0

            if not index_arr_flag:
                real = torch.cat([reals[id][scale_num] for id in index_image],
                                 dim=0)
                opt.nzx = real.shape[2]
                opt.nzy = real.shape[3]
                opt.receptive_field = opt.ker_size + (
                    (opt.ker_size - 1) *
                    (opt.num_layer - 1)) * opt.stride  # 11
                pad_noise = int(((opt.ker_size - 1) * opt.num_layer) / 2)  # 5
                m_noise = nn.ZeroPad2d(int(pad_noise))
                z_opt = functions.generate_noise([1, opt.nzx, opt.nzy],
                                                 device=opt.device)
                z_opt = m_noise(
                    z_opt.expand(real.shape[0], 3, opt.nzx, opt.nzy))

            elif index_arr_flag:
                z_opt = torch.cat(([Zs[id][scale_num] for id in index_image]),
                                  dim=0)

            in_s, G_curr = train_single_scale(D_curr, G_curr, reals, Gs, Zs,
                                              in_s, NoiseAmp, opt, index_image,
                                              z_opt, optimizerD, optimizerG,
                                              schedulerD, schedulerG,
                                              index_arr_flag)
            if not index_arr_flag:
                for id in index_image:
                    Zs[id].append(z_opt[id:id + 1])
                    NoiseAmp[id].append(opt.noise_amp[id:id + 1])
            else:
                for id in index_image:
                    NoiseAmp[id][scale_num] = opt.noise_amp[id:id + 1]

            index_arr_flag = True

            G_curr = functions.reset_grads(G_curr, False)
            G_curr.eval()
            D_curr = functions.reset_grads(D_curr, False)
            D_curr.eval()

        Gs.append(G_curr)
        torch.save(Zs, '%s/Zs.pth' % (opt.out_))
        torch.save(Gs, '%s/Gs.pth' % (opt.out_))
        torch.save(reals, '%s/reals.pth' % (opt.out_))
        torch.save(NoiseAmp, '%s/NoiseAmp.pth' % (opt.out_))

        scale_num += 1
        nfc_prev = opt.nfc
        del D_curr, G_curr, optimizerD, optimizerG
        torch.cuda.empty_cache()

    return
def train_single_scale(netD,
                       netG,
                       reals,
                       Gs,
                       Zs,
                       in_s,
                       NoiseAmp,
                       opt,
                       index_image,
                       z_opt,
                       optimizerD,
                       optimizerG,
                       schedulerD,
                       schedulerG,
                       is_passing_im_before,
                       centers=None):

    real = torch.cat([reals[id][len(Gs)] for id in index_image], dim=0)
    pad_noise = int(((opt.ker_size - 1) * opt.num_layer) / 2)
    pad_image = int(((opt.ker_size - 1) * opt.num_layer) / 2)

    m_noise = nn.ZeroPad2d(int(pad_noise))
    m_image = nn.ZeroPad2d(int(pad_image))
    alpha = opt.alpha

    errD2plot = []
    errG2plot = []
    D_real2plot = []
    z_opt2plot = []

    for epoch in range(opt.niter):

        if Gs == []:
            noise_ = functions.generate_noise([1, opt.nzx, opt.nzy],
                                              device=opt.device,
                                              num_samp=real.shape[0])
            noise_ = m_noise(noise_.expand(real.shape[0], 3, opt.nzx, opt.nzy))
        else:
            noise_ = functions.generate_noise([opt.nc_z, opt.nzx, opt.nzy],
                                              device=opt.device,
                                              num_samp=real.shape[0])
            noise_ = m_noise(noise_)

        ############################
        # (1) Update D network: maximize D(x) + D(G(z))
        ###########################

        for p in netD.parameters():
            p.requires_grad = True  # to avoid computation

        for j in range(opt.Dsteps):
            netD.zero_grad()
            reals_arr = []
            num_transforms = 0
            for index_transform, pair in enumerate(opt.list_transformations):
                num_transforms += 1
                flag_color, is_flip, tx, ty, k_rotate = pair
                real_transform = apply_augmentation(real, is_flip, tx, ty,
                                                    k_rotate,
                                                    flag_color).to(opt.device)
                real_transform = torch.squeeze(real_transform)
                reals_arr.append(real_transform)
            opt.num_transforms = num_transforms

            num_transforms_range = range(opt.num_transforms)
            real_transform = torch.stack(reals_arr)
            if opt.num_images > 1:
                real_transform = real_transform.reshape(
                    -1, real_transform.shape[2], real_transform.shape[3],
                    real_transform.shape[4])

            output = netD(real_transform)
            if isinstance(output, list):
                id_padding = [
                    torch.full((opt.num_images, 1, output[0].shape[2],
                                output[0].shape[3]),
                               id,
                               dtype=torch.float)
                    for id in num_transforms_range
                ]
            else:
                id_padding = [
                    torch.full(
                        (opt.num_images, 1, output.shape[2], output.shape[3]),
                        id,
                        dtype=torch.float).to(opt.device)
                    for id in num_transforms_range
                ]

            errD_real = get_err_D_real_and_backward(output, id_padding,
                                                    opt.device_ids)
            D_x = -errD_real.item()

            # train with fake - this is the first time in this scale
            if (j == 0) & (epoch == 0):
                if (Gs == []) & (is_passing_im_before == False):
                    prev = torch.full(
                        [real.shape[0], opt.nc_z, opt.nzx, opt.nzy],
                        0,
                        device=opt.device,
                        dtype=torch.long)
                    in_s = prev
                    prev = m_image(prev)
                    z_prev = torch.full(
                        [real.shape[0], opt.nc_z, opt.nzx, opt.nzy],
                        0,
                        device=opt.device,
                        dtype=torch.long)
                    z_prev = m_noise(z_prev)
                    opt.noise_amp = torch.full([real.shape[0], 1],
                                               1,
                                               dtype=torch.long).to(opt.device)
                    opt.noise_amp_tensor = torch.full(
                        [real.shape[0], opt.nc_z, opt.nzx, opt.nzy],
                        1,
                        dtype=torch.long).to(opt.device)

                else:
                    prev = draw_concat(Gs,
                                       Zs,
                                       reals,
                                       NoiseAmp,
                                       in_s,
                                       'rand',
                                       m_noise,
                                       m_image,
                                       opt,
                                       index_image,
                                       cuda_device=opt.device)
                    prev = m_image(prev)
                    z_prev = draw_concat(Gs,
                                         Zs,
                                         reals,
                                         NoiseAmp,
                                         in_s,
                                         'rec',
                                         m_noise,
                                         m_image,
                                         opt,
                                         index_image,
                                         cuda_device=opt.device)
                    criterion = nn.MSELoss(reduction='none')
                    opt.noise_amp = torch.cat(([
                        NoiseAmp[id][len(Gs) - 1]
                        for id in range(opt.num_images)
                    ]),
                                              dim=0).to(opt.device)

                    if not is_passing_im_before:
                        temp = criterion(real, z_prev)

                        RMSE = torch.sqrt(temp)
                        opt.noise_amp_init_tensor = torch.full(
                            [real.shape[0], opt.nc_z, opt.nzx, opt.nzy],
                            opt.noise_amp_init,
                            dtype=torch.float).to(opt.device)
                        opt.noise_amp = opt.noise_amp_init_tensor * RMSE
                        opt.noise_amp = torch.unsqueeze(torch.mean(
                            torch.flatten(opt.noise_amp, start_dim=1), dim=1),
                                                        dim=1)
                        opt.noise_amp_tensor = torch.full(
                            [1, opt.nc_z, opt.nzx, opt.nzy],
                            opt.noise_amp[0][0].item(),
                            dtype=torch.float).to(opt.device)
                        for i in range(1, real.shape[0]):
                            temp = torch.full([1, opt.nc_z, opt.nzx, opt.nzy],
                                              opt.noise_amp[i][0].item(),
                                              dtype=torch.float).to(opt.device)
                            opt.noise_amp_tensor = torch.cat(
                                (opt.noise_amp_tensor, temp), dim=0)

                    else:
                        opt.noise_amp = torch.cat(([
                            NoiseAmp[id][len(Gs) - 1]
                            for id in range(opt.num_images)
                        ]),
                                                  dim=0).to(opt.device)
                        opt.noise_amp_tensor = torch.full(
                            [1, opt.nc_z, opt.nzx, opt.nzy],
                            opt.noise_amp[0][0].item(),
                            dtype=torch.float).to(opt.device)
                        for i in range(1, real.shape[0]):
                            temp = torch.full([1, opt.nc_z, opt.nzx, opt.nzy],
                                              opt.noise_amp[i][0].item(),
                                              dtype=torch.float).to(opt.device)
                            opt.noise_amp_tensor = torch.cat(
                                (opt.noise_amp_tensor, temp), dim=0)
                    z_prev = m_image(z_prev)
            else:
                prev = draw_concat(Gs,
                                   Zs,
                                   reals,
                                   NoiseAmp,
                                   in_s,
                                   'rand',
                                   m_noise,
                                   m_image,
                                   opt,
                                   index_image,
                                   cuda_device=opt.device)
                prev = m_image(prev)
            if Gs == []:
                noise = noise_
            else:
                noise = m_noise(opt.noise_amp_tensor) * noise_ + prev
            padded_id_noise = pad_image_id(noise, index_image)
            fake = netG(padded_id_noise.detach(), prev)
            if isinstance(fake, list):
                fake = [tens.to(opt.device) for tens in fake]
                fake = torch.cat(fake)
            fakes_arr = []

            for index_transform, pair in enumerate(opt.list_transformations):
                flag_color, is_flip, tx, ty, k_rotate = pair
                fake_transform = apply_augmentation(fake.detach(), is_flip, tx,
                                                    ty, k_rotate,
                                                    flag_color).to(opt.device)
                fake_transform = torch.squeeze(fake_transform)
                fakes_arr.append(fake_transform)
            fake_transform = torch.stack(fakes_arr)
            if opt.num_images > 1:
                fake_transform = fake_transform.reshape(
                    -1, fake_transform.shape[2], fake_transform.shape[3],
                    fake_transform.shape[4])
            output = netD(fake_transform)
            errD_fake = get_err_D_fake_and_backward(output, opt.num_transforms,
                                                    opt.num_images,
                                                    opt.device_ids)
            if isinstance(output, list):
                output = [tens.to(opt.device) for tens in output]
                output = torch.cat(output)
            D_G_z = output.mean().item()
            errD = errD_real + errD_fake
            if j == opt.Dsteps - 1 and index_transform == opt.num_transforms - 1 and (
                    epoch % 50 == 0 or epoch == (opt.niter - 1)):
                print("errD real: ", D_x, "errD fake: ", D_G_z)

            optimizerD.step()

        errD2plot.append(errD.detach())

        ############################
        # (2) Update G network: maximize D(G(z))
        ###########################

        for p in netD.parameters():
            p.requires_grad = False  # to avoid computation

        for j in range(opt.Gsteps):
            netG.zero_grad()
            padded_id_noise = pad_image_id(noise, index_image)
            fake = netG(padded_id_noise, prev)
            if isinstance(fake, list):
                fake = [tens.to(opt.device) for tens in fake]
                fake = torch.cat(fake)
            fakes_arr_G = []

            for index_transform, pair in enumerate(opt.list_transformations):
                flag_color, is_flip, tx, ty, k_rotate = pair
                fake_transform_G = apply_augmentation(
                    fake, is_flip, tx, ty, k_rotate, flag_color).to(opt.device)
                fake_transform_G = torch.squeeze(fake_transform_G)
                fakes_arr_G.append(fake_transform_G)
            fake_transform_G = torch.stack(fakes_arr_G)
            if opt.num_images > 1:
                fake_transform_G = fake_transform_G.reshape(
                    -1, fake_transform_G.shape[2], fake_transform_G.shape[3],
                    fake_transform_G.shape[4])
            output = netD(fake_transform_G)
            if isinstance(output, list):
                id_padding = [
                    torch.full((opt.num_images, 1, output[0].shape[2],
                                output[0].shape[3]),
                               id,
                               dtype=torch.float).to(opt.device)
                    for id in num_transforms_range
                ]
            else:
                id_padding = [
                    torch.full(
                        (opt.num_images, 1, output.shape[2], output.shape[3]),
                        id,
                        dtype=torch.float).to(opt.device)
                    for id in num_transforms_range
                ]
            errG = get_err_G_fake_and_backward(output, id_padding,
                                               opt.device_ids)

            if alpha != 0:
                loss = nn.MSELoss()
                Z_opt = m_noise(opt.noise_amp_tensor) * z_opt + z_prev
                padded_id_Z_opt = pad_image_id(Z_opt.detach(), index_image)
                negG_output = netG(padded_id_Z_opt.detach(), z_prev)
                if isinstance(output, list):
                    negG_output = [tens.to(opt.device) for tens in negG_output]
                    negG_output = torch.cat(negG_output)
                rec_loss = alpha * loss(negG_output, real)

                rec_loss.backward(retain_graph=True)
                rec_loss = rec_loss.detach()

            else:
                Z_opt = z_opt
                rec_loss = 0
            if j == opt.Gsteps - 1 and index_transform == opt.num_transforms - 1 and (
                    epoch % 50 == 0 or epoch == (opt.niter - 1)):
                print("errG fake: ",
                      errG.detach().item(), "rec loss: ",
                      rec_loss.detach().item())

            optimizerG.step()

        errG2plot.append(errG.detach() + rec_loss)
        D_real2plot.append(D_x)
        z_opt2plot.append(rec_loss)

        if (epoch % 25 == 0 or epoch == (opt.niter - 1)):
            print('scale %d:[%d/%d]' % (len(Gs), epoch, opt.niter))
            print(" ")

        if index_transform == opt.num_transforms - 1 and (
                epoch % 150 == 0 or epoch == (opt.niter - 1)):
            for j, id in enumerate(opt.outf):
                plt.imsave('%s/fake_sample_epoch%d.png' % (id, epoch),
                           functions.convert_image_np(fake[j:j + 1].detach()),
                           vmin=0,
                           vmax=1)
            padded_id_Z_opt = pad_image_id(Z_opt.detach(), index_image)
            G_z_opt = netG(padded_id_Z_opt.detach(), z_prev.detach())
            if isinstance(G_z_opt, list):
                G_z_opt = [tens.to(opt.device) for tens in G_z_opt]
                G_z_opt = torch.cat(G_z_opt)
            for j, id in enumerate(opt.outf):
                plt.imsave('%s/G(z_opt)_epoch%d.png' % (id, epoch),
                           functions.convert_image_np(G_z_opt[j:j +
                                                              1].detach()),
                           vmin=0,
                           vmax=1)
            torch.save(z_opt, '%s/z_opt.pth' % (opt.global_outf))
        schedulerD.step()
        schedulerG.step()

    functions.save_networks(netG, netD, z_opt, opt)
    return in_s, netG
コード例 #4
0
def SinGAN_generate(Gs,Zs,reals,NoiseAmp,opt,in_s=None,scale_v=1,scale_h=1,n=0,gen_start_scale=0,num_samples=200):

    if in_s is None:
        in_s = torch.full(reals[0][0].shape, 0, device=opt.device, dtype=torch.long)
    images_cur = []
    index_image = range(int(opt.num_images))

    for scale_idx, (G) in enumerate(Gs):
        Z_opt = torch.cat([Zs[idx][scale_idx] for idx in index_image], dim=0)
        noise_amp = torch.cat(([NoiseAmp[id][scale_idx] for id in range(opt.num_images)]), dim=0).cuda()
        pad1 = ((opt.ker_size-1)*opt.num_layer)/2
        m = nn.ZeroPad2d(int(pad1))
        nzx = (Z_opt.shape[2]-pad1*2)*scale_v
        nzy = (Z_opt.shape[3]-pad1*2)*scale_h
        images_prev = images_cur
        images_cur = []

        for i in range(0,num_samples,1):
            if n == 0:
                z_curr = functions.generate_noise([1,nzx,nzy], device=opt.device)
                z_curr = z_curr.expand(1,3,z_curr.shape[2],z_curr.shape[3])
                z_curr = m(z_curr)
            else:
                z_curr = functions.generate_noise([opt.nc_z,nzx,nzy], device=opt.device)
                z_curr = m(z_curr)

            if images_prev == []:
                I_prev = m(in_s)
            else:
                I_prev_temp = images_prev[i]
                I_prev = imresize(torch.unsqueeze(I_prev_temp[0], dim=0), 1 / opt.scale_factor, opt)
                for id in range(1, opt.num_images):
                    I_prev = torch.cat((I_prev, imresize(torch.unsqueeze(I_prev_temp[id], dim=0), 1 / opt.scale_factor, opt)),
                                    dim=0)
                if opt.mode != "SR":
                    I_prev = I_prev[:, :, 0:round(scale_v * reals[0][n].shape[2]), 0:round(scale_h * reals[0][n].shape[3])]
                    I_prev = m(I_prev)
                    I_prev = I_prev[:,:,0:z_curr.shape[2],0:z_curr.shape[3]]
                    I_prev = functions.upsampling(I_prev,z_curr.shape[2],z_curr.shape[3])
                else:
                    I_prev = m(I_prev)

            if n < gen_start_scale:
                z_curr = Z_opt

            noise_amp_tensor = torch.full([1, z_curr.shape[1], z_curr.shape[2], z_curr.shape[3]], noise_amp[0][0].item(),
                                          dtype=torch.float).cuda()
            for j in range(1, opt.num_images):
                temp = torch.full([1, z_curr.shape[1], z_curr.shape[2], z_curr.shape[3]],
                                  noise_amp[j][0].item(), dtype=torch.float).cuda()
                noise_amp_tensor = torch.cat((noise_amp_tensor, temp), dim=0)
            z_in = noise_amp_tensor*(z_curr)+I_prev
            padded_id_Z_opt = pad_image_id(z_in, index_image)


            I_curr = G(padded_id_Z_opt.detach(),I_prev)

            if n == len(Gs)-1:
                if opt.mode == 'train':
                    dir2save = '%s/RandomSamples/%s/gen_start_scale=%d' % (opt.out, opt.input_name[:-4], gen_start_scale)
                else:
                    dir2save = functions.generate_dir2save(opt)
                try:
                    os.makedirs(dir2save)
                except OSError:
                    pass
                if (opt.mode != "harmonization") & (opt.mode != "editing") & (opt.mode != "SR") & (opt.mode != "paint2image"):
                    for j in range(opt.num_images):

                        plt.imsave('%s/%d%d.png' % (dir2save, i,j), functions.convert_image_np(I_curr[j].unsqueeze(dim=0).detach()), vmin=0,vmax=1)
            images_cur.append(I_curr)
        n+=1
    return I_curr.detach()