test_ddgan.py

# ---------------------------------------------------------------
# Copyright (c) 2022, NVIDIA CORPORATION. All rights reserved.
#
# This work is licensed under the NVIDIA Source Code License
# for Denoising Diffusion GAN. To view a copy of this license, see the LICENSE file.
# ---------------------------------------------------------------
import argparse
import torch
import numpy as np
import time
import os
import json
import torchvision
import random

from score_sde.models.ncsnpp_generator_adagn import NCSNpp
from torch.nn.functional import adaptive_avg_pool2d

try:
    from pytorch_fid.fid_score import calculate_activation_statistics, calculate_fid_given_paths, ImagePathDataset, compute_statistics_of_path, calculate_frechet_distance
    from pytorch_fid.inception import InceptionV3
except ImportError:
    pass

try:
    import ImageReward as RM
except ImportError:
    pass


try:
    import clip
except ImportError:
    pass

from encoder import build_encoder
from clip_encoder import CLIPImageEncoder

from model_configs import get_model_config

#%% Diffusion coefficients 
def var_func_vp(t, beta_min, beta_max):
    log_mean_coeff = -0.25 * t ** 2 * (beta_max - beta_min) - 0.5 * t * beta_min
    var = 1. - torch.exp(2. * log_mean_coeff)
    return var

def var_func_geometric(t, beta_min, beta_max):
    return beta_min * ((beta_max / beta_min) ** t)

def extract(input, t, shape):
    out = torch.gather(input, 0, t)
    reshape = [shape[0]] + [1] * (len(shape) - 1)
    out = out.reshape(*reshape)

    return out

def get_time_schedule(args, device):
    n_timestep = args.num_timesteps
    eps_small = 1e-3
    t = np.arange(0, n_timestep + 1, dtype=np.float64)
    t = t / n_timestep
    t = torch.from_numpy(t) * (1. - eps_small)  + eps_small
    return t.to(device)

def get_sigma_schedule(args, device):
    n_timestep = args.num_timesteps
    beta_min = args.beta_min
    beta_max = args.beta_max
    eps_small = 1e-3
   
    t = np.arange(0, n_timestep + 1, dtype=np.float64)
    t = t / n_timestep
    t = torch.from_numpy(t) * (1. - eps_small) + eps_small
    
    if args.use_geometric:
        var = var_func_geometric(t, beta_min, beta_max)
    else:
        var = var_func_vp(t, beta_min, beta_max)
    alpha_bars = 1.0 - var
    betas = 1 - alpha_bars[1:] / alpha_bars[:-1]
    
    first = torch.tensor(1e-8)
    betas = torch.cat((first[None], betas)).to(device)
    betas = betas.type(torch.float32)
    sigmas = betas**0.5
    a_s = torch.sqrt(1-betas)
    return sigmas, a_s, betas

#%% posterior sampling
class Posterior_Coefficients():
    def __init__(self, args, device):
        
        _, _, self.betas = get_sigma_schedule(args, device=device)
        
        #we don't need the zeros
        self.betas = self.betas.type(torch.float32)[1:]
        
        self.alphas = 1 - self.betas
        self.alphas_cumprod = torch.cumprod(self.alphas, 0)
        self.alphas_cumprod_prev = torch.cat(
                                    (torch.tensor([1.], dtype=torch.float32,device=device), self.alphas_cumprod[:-1]), 0
                                        )               
        self.posterior_variance = self.betas * (1 - self.alphas_cumprod_prev) / (1 - self.alphas_cumprod)
        
        self.sqrt_alphas_cumprod = torch.sqrt(self.alphas_cumprod)
        self.sqrt_recip_alphas_cumprod = torch.rsqrt(self.alphas_cumprod)
        self.sqrt_recipm1_alphas_cumprod = torch.sqrt(1 / self.alphas_cumprod - 1)
        
        self.posterior_mean_coef1 = (self.betas * torch.sqrt(self.alphas_cumprod_prev) / (1 - self.alphas_cumprod))
        self.posterior_mean_coef2 = ((1 - self.alphas_cumprod_prev) * torch.sqrt(self.alphas) / (1 - self.alphas_cumprod))
        
        self.posterior_log_variance_clipped = torch.log(self.posterior_variance.clamp(min=1e-20))

def predict_q_posterior(coefficients, x_0, x_t, t):
    mean = (
        extract(coefficients.posterior_mean_coef1, t, x_t.shape) * x_0
        + extract(coefficients.posterior_mean_coef2, t, x_t.shape) * x_t
    )
    var = extract(coefficients.posterior_variance, t, x_t.shape)
    log_var_clipped = extract(coefficients.posterior_log_variance_clipped, t, x_t.shape)
    return mean, var, log_var_clipped



def sample_posterior(coefficients, x_0,x_t, t):
    
    def q_posterior(x_0, x_t, t):
        mean = (
            extract(coefficients.posterior_mean_coef1, t, x_t.shape) * x_0
            + extract(coefficients.posterior_mean_coef2, t, x_t.shape) * x_t
        )
        var = extract(coefficients.posterior_variance, t, x_t.shape)
        log_var_clipped = extract(coefficients.posterior_log_variance_clipped, t, x_t.shape)
        return mean, var, log_var_clipped
    
  
    def p_sample(x_0, x_t, t):
        mean, _, log_var = q_posterior(x_0, x_t, t)
        
        noise = torch.randn_like(x_t)
        
        nonzero_mask = (1 - (t == 0).type(torch.float32))

        return mean + nonzero_mask[:,None,None,None] * torch.exp(0.5 * log_var) * noise
            
    sample_x_pos = p_sample(x_0, x_t, t)
    
    return sample_x_pos

def sample_from_model(coefficients, generator, n_time, x_init, T, opt, cond=None):
    x = x_init
    with torch.no_grad():
        for i in reversed(range(n_time)):
            t = torch.full((x.size(0),), i, dtype=torch.int64).to(x.device)
            
            t_time = t
            latent_z = torch.randn(x.size(0), opt.nz, device=x.device)#.to(x.device)
            x_0 = generator(x, t_time, latent_z, cond=cond)
            x_new = sample_posterior(coefficients, x_0, x, t)
            x = x_new.detach()
        
    return x


def sample(generator, x_init, cond=None):
    return sample_from_model(
        generator.pos_coeff, generator, n_time=generator.config.num_timesteps, x_init=x_init, 
        T=generator.time_schedule, opt=generator.config, cond=cond
    )

def sample_from_model_classifier_free_guidance(coefficients, generator, n_time, x_init, T, opt, text_encoder, cond=None, guidance_scale=0):
    x = x_init
    null = text_encoder([""] * len(x_init), return_only_pooled=False)
    #latent_z = torch.randn(x.size(0), opt.nz, device=x.device)
    with torch.no_grad():
        for i in reversed(range(n_time)):
            t = torch.full((x.size(0),), i, dtype=torch.int64).to(x.device)
            t_time = t
            
            latent_z = torch.randn(x.size(0), opt.nz, device=x.device)
            
            x_0_uncond = generator(x, t_time, latent_z, cond=null)
            
            #latent_z = torch.randn(x.size(0), opt.nz, device=x.device)
            
            x_0_cond = generator(x, t_time, latent_z, cond=cond)

            eps_uncond = (x - torch.sqrt(coefficients.alphas_cumprod[i]) * x_0_uncond) / torch.sqrt(1 - coefficients.alphas_cumprod[i])
            eps_cond = (x - torch.sqrt(coefficients.alphas_cumprod[i]) * x_0_cond) / torch.sqrt(1 - coefficients.alphas_cumprod[i])
            
            # eps = eps_uncond + guidance_scale * (eps_cond - eps_uncond)
            eps = eps_uncond * (1 - guidance_scale) + eps_cond * guidance_scale
            x_0 = (1/torch.sqrt(coefficients.alphas_cumprod[i])) * (x - torch.sqrt(1 - coefficients.alphas_cumprod[i]) * eps)
            #x_0 = x_0_uncond * (1 - guidance_scale) + x_0_cond * guidance_scale

            # Dynamic thresholding
            q = opt.dynamic_thresholding_quantile
            #print("Before", x_0.min(), x_0.max())
            if q:
                shape = x_0.shape
                x_0_v = x_0.view(shape[0], -1)
                d = torch.quantile(torch.abs(x_0_v), q, dim=1, keepdim=True)
                d.clamp_(min=1)
                x_0_v = x_0_v.clamp(-d, d) / d
                x_0 = x_0_v.view(shape)
            #print("After", x_0.min(), x_0.max())
            
            x_new = sample_posterior(coefficients, x_0, x, t)
            
            # Dynamic thresholding
            # q = args.dynamic_thresholding_percentile
            # shape = x_new.shape
            # x_new_v = x_new.view(shape[0], -1)
            # d = torch.quantile(torch.abs(x_new_v), q, dim=1, keepdim=True)
            # d = torch.maximum(d, torch.ones_like(d))
            # d.clamp_(min = 1.)
            # x_new_v = torch.clamp(x_new_v, -d, d) / d
            # x_new = x_new_v.view(shape)
            x = x_new.detach()
        
    return x


def sample_from_model_classifier_free_guidance_convolutional(coefficients, generator, n_time, x_init, T, opt, text_encoder, cond=None, guidance_scale=0, split_input_params=None):
    x = x_init
    null = text_encoder([""] * len(x_init), return_only_pooled=False)
    #latent_z = torch.randn(x.size(0), opt.nz, device=x.device)
    ks = split_input_params["ks"]  # eg. (128, 128)
    stride = split_input_params["stride"]  # eg. (64, 64)
    uf = split_input_params["vqf"]
    with torch.no_grad():
        for i in reversed(range(n_time)):
            t = torch.full((x.size(0),), i, dtype=torch.int64).to(x.device)
            t_time = t
            latent_z = torch.randn(x.size(0), opt.nz, device=x.device)
            
            fold, unfold, normalization, weighting = get_fold_unfold(x, ks, stride, split_input_params, uf=uf)
            x = unfold(x)
            x = x.view((x.shape[0], -1, ks[0], ks[1], x.shape[-1])) 
            x_new_list = []
            for j in range(x.shape[-1]):
                x_0_uncond = generator(x[:,:,:,:,j], t_time, latent_z, cond=null)            
                x_0_cond = generator(x[:,:,:,:,j], t_time, latent_z, cond=cond)

                eps_uncond = (x[:,:,:,:,j] - torch.sqrt(coefficients.alphas_cumprod[i]) * x_0_uncond) / torch.sqrt(1 - coefficients.alphas_cumprod[i])
                eps_cond = (x[:,:,:,:,j] - torch.sqrt(coefficients.alphas_cumprod[i]) * x_0_cond) / torch.sqrt(1 - coefficients.alphas_cumprod[i])
                
                eps = eps_uncond * (1 - guidance_scale) + eps_cond * guidance_scale
                x_0 = (1/torch.sqrt(coefficients.alphas_cumprod[i])) * (x[:,:,:,:,j] - torch.sqrt(1 - coefficients.alphas_cumprod[i]) * eps)
                q = args.dynamic_thresholding_quantile
                if q:
                    shape = x_0.shape
                    x_0_v = x_0.view(shape[0], -1)
                    d = torch.quantile(torch.abs(x_0_v), q, dim=1, keepdim=True)
                    d.clamp_(min=1)
                    x_0_v = x_0_v.clamp(-d, d) / d
                    x_0 = x_0_v.view(shape)
                x_new = sample_posterior(coefficients, x_0, x[:,:,:,:,j], t)
                x_new_list.append(x_new)
            
            o = torch.stack(x_new_list, axis=-1) 
            #o = o * weighting
            o = o.view((o.shape[0], -1, o.shape[-1])) 
            decoded = fold(o)
            decoded = decoded / normalization
            x = decoded.detach()
        
    return x

def sample_from_model_clip_guidance(coefficients, generator, clip_model, n_time, x_init, T, opt, texts, cond=None, guidance_scale=0):
    x = x_init
    text_features = torch.nn.functional.normalize(clip_model.forward_text(texts), dim=1)
    n_time = 16
    for i in reversed(range(n_time)):
        t = torch.full((x.size(0),), i%4, dtype=torch.int64).to(x.device)
        t_time = t            
        latent_z = torch.randn(x.size(0), opt.nz, device=x.device)
        x.requires_grad = True
        x_0 = generator(x, t_time, latent_z, cond=cond)
        x_new = sample_posterior(coefficients, x_0, x, t)
        x_new_n = (x_new + 1) / 2
        image_features = torch.nn.functional.normalize(clip_model.forward_image(x_new_n), dim=1)
        loss = (image_features*text_features).sum(dim=1).mean()
        x_grad, = torch.autograd.grad(loss, x)
        lr = 3000
        x = x.detach()
        print(x.min(),x.max(), lr*x_grad.min(), lr*x_grad.max())
        x += x_grad * lr

        with torch.no_grad():
            x_0 = generator(x, t_time, latent_z, cond=cond)
            x_new = sample_posterior(coefficients, x_0, x, t)

        x = x_new.detach()
        print(i)
    return x

def meshgrid(h, w):
    y = torch.arange(0, h).view(h, 1, 1).repeat(1, w, 1)
    x = torch.arange(0, w).view(1, w, 1).repeat(h, 1, 1)

    arr = torch.cat([y, x], dim=-1)
    return arr
def delta_border(h, w):
        """
        :param h: height
        :param w: width
        :return: normalized distance to image border,
         wtith min distance = 0 at border and max dist = 0.5 at image center
        """
        lower_right_corner = torch.tensor([h - 1, w - 1]).view(1, 1, 2)
        arr = meshgrid(h, w) / lower_right_corner
        dist_left_up = torch.min(arr, dim=-1, keepdims=True)[0]
        dist_right_down = torch.min(1 - arr, dim=-1, keepdims=True)[0]
        edge_dist = torch.min(torch.cat([dist_left_up, dist_right_down], dim=-1), dim=-1)[0]
        return edge_dist

def get_weighting(h, w, Ly, Lx, device, split_input_params):
    weighting = delta_border(h, w)
    weighting = torch.clip(weighting, split_input_params["clip_min_weight"],
                            split_input_params["clip_max_weight"], )
    weighting = weighting.view(1, h * w, 1).repeat(1, 1, Ly * Lx).to(device)

    if split_input_params["tie_braker"]:
        L_weighting = delta_border(Ly, Lx)
        L_weighting = torch.clip(L_weighting,
                                    split_input_params["clip_min_tie_weight"],
                                    split_input_params["clip_max_tie_weight"])

        L_weighting = L_weighting.view(1, 1, Ly * Lx).to(device)
        weighting = weighting * L_weighting
    return weighting

def get_fold_unfold(x, kernel_size, stride, split_input_params, uf=1, df=1):  # todo load once not every time, shorten code
    """
    :param x: img of size (bs, c, h, w)
    :return: n img crops of size (n, bs, c, kernel_size[0], kernel_size[1])
    """
    bs, nc, h, w = x.shape

    # number of crops in image
    Ly = (h - kernel_size[0]) // stride[0] + 1
    Lx = (w - kernel_size[1]) // stride[1] + 1

    if uf == 1 and df == 1:
        fold_params = dict(kernel_size=kernel_size, dilation=1, padding=0, stride=stride)
        unfold = torch.nn.Unfold(**fold_params)

        fold = torch.nn.Fold(output_size=x.shape[2:], **fold_params)

        weighting = get_weighting(kernel_size[0], kernel_size[1], Ly, Lx, x.device, split_input_params).to(x.dtype)
        normalization = fold(weighting).view(1, 1, h, w)  # normalizes the overlap
        weighting = weighting.view((1, 1, kernel_size[0], kernel_size[1], Ly * Lx))

    elif uf > 1 and df == 1:
        fold_params = dict(kernel_size=kernel_size, dilation=1, padding=0, stride=stride)
        unfold = torch.nn.Unfold(**fold_params)

        fold_params2 = dict(kernel_size=(kernel_size[0] * uf, kernel_size[0] * uf),
                            dilation=1, padding=0,
                            stride=(stride[0] * uf, stride[1] * uf))
        fold = torch.nn.Fold(output_size=(x.shape[2] * uf, x.shape[3] * uf), **fold_params2)

        weighting = get_weighting(kernel_size[0] * uf, kernel_size[1] * uf, Ly, Lx, x.device, split_input_params).to(x.dtype)
        normalization = fold(weighting).view(1, 1, h * uf, w * uf)  # normalizes the overlap
        weighting = weighting.view((1, 1, kernel_size[0] * uf, kernel_size[1] * uf, Ly * Lx))

    elif df > 1 and uf == 1:
        fold_params = dict(kernel_size=kernel_size, dilation=1, padding=0, stride=stride)
        unfold = torch.nn.Unfold(**fold_params)

        fold_params2 = dict(kernel_size=(kernel_size[0] // df, kernel_size[0] // df),
                            dilation=1, padding=0,
                            stride=(stride[0] // df, stride[1] // df))
        fold = torch.nn.Fold(output_size=(x.shape[2] // df, x.shape[3] // df), **fold_params2)

        weighting = get_weighting(kernel_size[0] // df, kernel_size[1] // df, Ly, Lx, x.device, split_input_params).to(x.dtype)
        normalization = fold(weighting).view(1, 1, h // df, w // df)  # normalizes the overlap
        weighting = weighting.view((1, 1, kernel_size[0] // df, kernel_size[1] // df, Ly * Lx))

    else:
        raise NotImplementedError

    return fold, unfold, normalization, weighting

class ObjectFromDict:
    def __init__(self, d):
        self.__dict__ = d

def load_model(config, path, device="cpu"):
    config = ObjectFromDict(config)
    print(config)
    text_encoder = build_encoder(name=config.text_encoder, masked_mean=config.masked_mean)
    print(text_encoder)
    config.cond_size = text_encoder.output_size
    netG = NCSNpp(config)
    print(netG)
    ckpt = torch.load(path, map_location="cpu")
    print("CK", ckpt)
    for key in list(ckpt.keys()):
        if key.startswith("module"):
            ckpt[key[7:]] = ckpt.pop(key)
    netG.load_state_dict(ckpt)
    netG.eval()
    netG.pos_coeff = Posterior_Coefficients(config, device)
    netG.text_encoder = text_encoder
    netG.config = config
    netG.time_schedule = get_time_schedule(config, device)
    netG = netG.to(device)
    return netG


#%%


def sample_and_test(args):
    torch.manual_seed(args.seed)
    device = 'cuda' if torch.cuda.is_available() else 'cpu'
    to_range_0_1 = lambda x: (x + 1.) / 2.     
    if args.epoch_id == -1:
        epochs = range(1000)
    else:
        epochs = [args.epoch_id]
    if args.compute_image_reward:
        #image_reward = RM.load("ImageReward-v1.0", download_root=".").to(device)
        image_reward = RM.load("ImageReward.pt", download_root=".").to(device)
    cfg = get_model_config(args.name)
    for epoch in epochs:
        args.epoch_id = epoch

        path = './saved_info/dd_gan/{}/{}/netG_{}.pth'.format(cfg['dataset'], args.name, args.epoch_id)
        next_path = './saved_info/dd_gan/{}/{}/netG_{}.pth'.format(cfg['dataset'], args.name, args.epoch_id+1)
        print(path)
        if not os.path.exists(path):
            continue
        if not os.path.exists(next_path):
            break
        print("PATH", path)
        suffix = '_' + args.eval_name if args.eval_name else ""
        dest = './saved_info/dd_gan/{}/{}/eval_{}{}.json'.format(cfg['dataset'], args.name, args.epoch_id, suffix)
        if (args.compute_fid or args.compute_clip_score or args.compute_image_reward) and  os.path.exists(dest):
            continue
        print("Load epoch", args.epoch_id, "checkpoint")

        netG = load_model(cfg, path, device=device)
        save_dir = "./generated_samples/{}".format(cfg['dataset'])
        
        if not os.path.exists(save_dir):
            os.makedirs(save_dir)
        

        if args.compute_fid or args.compute_clip_score or args.compute_image_reward:
            # Evaluate
            random.seed(args.seed)
            texts = open(args.cond_text).readlines()
            texts = [t.strip() for t in texts]
            if args.nb_images_for_fid:
                random.shuffle(texts)
                texts = texts[0:args.nb_images_for_fid]
            print("Text size:", len(texts))
            i = 0
            if args.compute_fid:
                dims = 2048
                block_idx = InceptionV3.BLOCK_INDEX_BY_DIM[dims]
                inceptionv3 = InceptionV3([block_idx]).to(device)

            if args.compute_clip_score:
                CLIP_MEAN = [0.48145466, 0.4578275, 0.40821073]
                CLIP_STD = [0.26862954, 0.26130258, 0.27577711]
                clip_model, preprocess = clip.load(args.clip_model, device)
                clip_mean = torch.Tensor(CLIP_MEAN).view(1,-1,1,1).to(device)
                clip_std = torch.Tensor(CLIP_STD).view(1,-1,1,1).to(device)

            if args.compute_fid:
                if not args.real_img_dir.endswith("npz"):
                    real_mu, real_sigma = compute_statistics_of_path(
                        args.real_img_dir, inceptionv3, args.batch_size, dims, device, 
                        resize=args.image_size,
                    )
                    np.savez("inception_statistics.npz", mu=real_mu, sigma=real_sigma)
                else:
                    stats = np.load(args.real_img_dir)
                    real_mu = stats['mu']
                    real_sigma = stats['sigma']

                fake_features = []
            
            if args.compute_clip_score:
                clip_scores = []
            if args.compute_image_reward:
                image_rewards = []
            
            for b in range(0, len(texts), args.batch_size):
                text = texts[b:b+args.batch_size]
                with torch.no_grad():
                    cond = netG.text_encoder(text)
                    bs = len(text)
                    t0 = time.time()
                    x_t_1 = torch.randn(bs, cfg['num_channels'], cfg['image_size'], cfg['image_size']).to(device)
                    if args.guidance_scale:
                        fake_sample = sample_from_model_classifier_free_guidance(pos_coeff, netG, args.num_timesteps, x_t_1,T,  args, text_encoder, cond=cond, guidance_scale=args.guidance_scale)
                    else:
                        fake_sample = sample(generator=netG, x_init=x_t_1, cond=cond)
                    fake_sample = to_range_0_1(fake_sample)
               
                    if args.compute_fid:
                        with torch.no_grad():
                            pred = inceptionv3(fake_sample)[0]
                        # If model output is not scalar, apply global spatial average pooling.
                        # This happens if you choose a dimensionality not equal 2048.
                        if pred.size(2) != 1 or pred.size(3) != 1:
                            pred = adaptive_avg_pool2d(pred, output_size=(1, 1))
                        pred = pred.squeeze(3).squeeze(2).cpu().numpy()
                        fake_features.append(pred)

                    if args.compute_clip_score:
                        with torch.no_grad():
                            clip_ims = torch.nn.functional.interpolate(fake_sample, (224, 224), mode="bicubic")
                            clip_ims = (clip_ims - clip_mean) / clip_std
                            clip_txt = clip.tokenize(text, truncate=True).to(device)
                            imf = clip_model.encode_image(clip_ims)
                            txtf = clip_model.encode_text(clip_txt)
                            imf = torch.nn.functional.normalize(imf, dim=1)
                            txtf = torch.nn.functional.normalize(txtf, dim=1)
                            clip_scores.append(((imf * txtf).sum(dim=1)).cpu())

                    if args.compute_image_reward:
                        for k, img in enumerate(fake_sample):
                            img = img.cpu().numpy().transpose(1,2,0)
                            img = img * 255
                            img = img.astype(np.uint8)
                            text_k = text[k]
                            score = image_reward.score(text_k, img)
                            image_rewards.append(score)
                    if i % 10 == 0:
                        print('evaluating batch ', i, time.time() - t0)
                    #break
                i += 1

            results = {}
            if args.compute_fid:
                fake_features = np.concatenate(fake_features)
                fake_mu = np.mean(fake_features, axis=0)
                fake_sigma = np.cov(fake_features, rowvar=False)
                fid =  calculate_frechet_distance(real_mu, real_sigma, fake_mu, fake_sigma)
                results['fid'] = fid
            if args.compute_clip_score:
                clip_score = torch.cat(clip_scores).mean().item()
                results['clip_score'] = clip_score
            if args.compute_image_reward:
                reward = np.mean(image_rewards)
                results['image_reward'] = reward
            results.update(vars(args))
            with open(dest, "w") as fd:
                json.dump(results, fd)
            print(results)
        else:        
            # just generate some samples
            if args.cond_text.endswith(".txt"):
                texts = open(args.cond_text).readlines()
                texts = [t.strip() for t in texts]
            else:
                texts = [args.cond_text] * args.batch_size
            clip_guidance = False
            if clip_guidance:
                cond = text_encoder(texts, return_only_pooled=False)
                clip_image_model = CLIPImageEncoder().to(device)
                x_t_1 = torch.randn(len(texts), args.num_channels,args.image_size*args.scale_factor_h, args.image_size*args.scale_factor_w).to(device)
                fake_sample = sample_from_model_clip_guidance(pos_coeff, netG, clip_image_model, args.num_timesteps, x_t_1,T,  args, texts, cond=cond, guidance_scale=args.guidance_scale)
                fake_sample = to_range_0_1(fake_sample)
                torchvision.utils.save_image(fake_sample, './samples_{}.jpg'.format(args.dataset))

            else:
                cond = netG.text_encoder(texts)
                x_t_1 = torch.randn(len(texts), cfg['num_channels'], cfg['image_size'] * args.scale_factor_h, cfg['image_size'] * args.scale_factor_w).to(device)
                t0 = time.time()
                if args.guidance_scale:
                    if args.scale_factor_h > 1 or args.scale_factor_w > 1:
                        if args.scale_method == "convolutional":
                            split_input_params = {
                                "ks": (cfg['image_size'], cfg['image_size']),
                                "stride": (150,  150),
                                "clip_max_tie_weight": 0.5,
                                "clip_min_tie_weight": 0.01,
                                "clip_max_weight": 0.5,
                                "clip_min_weight": 0.01,

                                "tie_braker": True,
                                'vqf': 1,
                            }
                            fake_sample = sample_from_model_classifier_free_guidance_convolutional(pos_coeff, netG, args.num_timesteps, x_t_1,T,  args, text_encoder, cond=cond, guidance_scale=args.guidance_scale, split_input_params=split_input_params)
                        elif args.scale_method == "larger_input":
                            netG.attn_resolutions = [r * args.scale_factor_w for r in netG.attn_resolutions]
                            fake_sample = sample_from_model_classifier_free_guidance(pos_coeff, netG, args.num_timesteps, x_t_1,T,  args, text_encoder, cond=cond, guidance_scale=args.guidance_scale)
                    else:
                        fake_sample = sample_from_model_classifier_free_guidance(pos_coeff, netG, args.num_timesteps, x_t_1,T,  args, text_encoder, cond=cond, guidance_scale=args.guidance_scale)
                else:
                    fake_sample = sample(generator=netG, x_init=x_t_1, cond=cond)

                print(time.time() - t0)
                fake_sample = to_range_0_1(fake_sample)
                torchvision.utils.save_image(fake_sample, 'samples.jpg')            

if __name__ == '__main__':
    parser = argparse.ArgumentParser('ddgan parameters')
    parser.add_argument('--name', type=str, default="", help="model config name")
    parser.add_argument('--batch-size', type=int, default=16)
    parser.add_argument('--seed', type=int, default=1024, help='seed used for initialization')

    # by default, we just generate samples and save them to samples.jpg
    # for evaluation, one or several of the following should be set to True
    parser.add_argument('--compute-fid', action='store_true', default=False,
                            help='whether or not compute FID')
    parser.add_argument('--compute-clip-score', action='store_true', default=False,
                            help='whether or not compute CLIP score')
    parser.add_argument('--compute-image-reward', action='store_true', default=False,
                            help='whether or not compute CLIP score')

    # clip model for clip evaluation
    parser.add_argument('--clip-model', type=str,default="ViT-L/14")

    # nb images to use for FID evaluation
    parser.add_argument('--nb-images-for-fid', type=int, default=0)

    # eval name to use when saving the evaluation results
    parser.add_argument('--eval-name', type=str,default="")

    # epoch to use for evaluation, if -1, iterate over all epochs (for evaluation)
    parser.add_argument('--epoch-id', type=int,default=-1)


    parser.add_argument('--guidance-scale', type=float,default=0)
    parser.add_argument('--dynamic-thresholding-quantile', type=float,default=0)

    # either a text, or a .txt file, where each line is a prompt
    parser.add_argument('--scale-factor-h', type=int,default=1)
    parser.add_argument('--scale-factor-w', type=int,default=1)
    parser.add_argument('--scale-method', type=str,default="convolutional")
    parser.add_argument('--cond-text', type=str,default="a chair in the form of an avocado")

    args = parser.parse_args()
    sample_and_test(args)