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181 lines (156 loc) · 6.83 KB
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# Copyright 2023 The HuggingFace Team. All rights reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
import warnings
from typing import Union
import numpy as np
import PIL
import torch
from PIL import Image
from .configuration_utils import ConfigMixin, register_to_config
from .utils import CONFIG_NAME, PIL_INTERPOLATION
class VaeImageProcessor(ConfigMixin):
"""
Image Processor for VAE
Args:
do_resize (`bool`, *optional*, defaults to `True`):
Whether to downscale the image's (height, width) dimensions to multiples of `vae_scale_factor`.
vae_scale_factor (`int`, *optional*, defaults to `8`):
VAE scale factor. If `do_resize` is True, the image will be automatically resized to multiples of this
factor.
resample (`str`, *optional*, defaults to `lanczos`):
Resampling filter to use when resizing the image.
do_normalize (`bool`, *optional*, defaults to `True`):
Whether to normalize the image to [-1,1]
"""
config_name = CONFIG_NAME
@register_to_config
def __init__(
self,
do_resize: bool = True,
vae_scale_factor: int = 8,
resample: str = "lanczos",
do_normalize: bool = True,
):
super().__init__()
@staticmethod
def numpy_to_pil(images):
"""
Convert a numpy image or a batch of images to a PIL image.
"""
if images.ndim == 3:
images = images[None, ...]
images = (images * 255).round().astype("uint8")
if images.shape[-1] == 1:
# special case for grayscale (single channel) images
pil_images = [Image.fromarray(image.squeeze(), mode="L") for image in images]
else:
pil_images = [Image.fromarray(image) for image in images]
return pil_images
@staticmethod
def numpy_to_pt(images):
"""
Convert a numpy image to a pytorch tensor
"""
if images.ndim == 3:
images = images[..., None]
images = torch.from_numpy(images.transpose(0, 3, 1, 2))
return images
@staticmethod
def pt_to_numpy(images):
"""
Convert a numpy image to a pytorch tensor
"""
images = images.cpu().permute(0, 2, 3, 1).float().numpy()
return images
@staticmethod
def normalize(images):
"""
Normalize an image array to [-1,1]
"""
return 2.0 * images - 1.0
def resize(self, images: PIL.Image.Image) -> PIL.Image.Image:
"""
Resize a PIL image. Both height and width will be downscaled to the next integer multiple of `vae_scale_factor`
"""
w, h = images.size
w, h = (x - x % self.config.vae_scale_factor for x in (w, h)) # resize to integer multiple of vae_scale_factor
images = images.resize((w, h), resample=PIL_INTERPOLATION[self.config.resample])
return images
def preprocess(
self,
image: Union[torch.FloatTensor, PIL.Image.Image, np.ndarray],
) -> torch.Tensor:
"""
Preprocess the image input, accepted formats are PIL images, numpy arrays or pytorch tensors"
"""
supported_formats = (PIL.Image.Image, np.ndarray, torch.Tensor)
if isinstance(image, supported_formats):
image = [image]
elif not (isinstance(image, list) and all(isinstance(i, supported_formats) for i in image)):
raise ValueError(
f"Input is in incorrect format: {[type(i) for i in image]}. Currently, we only support {', '.join(supported_formats)}"
)
if isinstance(image[0], PIL.Image.Image):
if self.config.do_resize:
image = [self.resize(i) for i in image]
image = [np.array(i).astype(np.float32) / 255.0 for i in image]
image = np.stack(image, axis=0) # to np
image = self.numpy_to_pt(image) # to pt
elif isinstance(image[0], np.ndarray):
image = np.concatenate(image, axis=0) if image[0].ndim == 4 else np.stack(image, axis=0)
image = self.numpy_to_pt(image)
_, _, height, width = image.shape
if self.config.do_resize and (
height % self.config.vae_scale_factor != 0 or width % self.config.vae_scale_factor != 0
):
raise ValueError(
f"Currently we only support resizing for PIL image - please resize your numpy array to be divisible by {self.config.vae_scale_factor}"
f"currently the sizes are {height} and {width}. You can also pass a PIL image instead to use resize option in VAEImageProcessor"
)
elif isinstance(image[0], torch.Tensor):
image = torch.cat(image, axis=0) if image[0].ndim == 4 else torch.stack(image, axis=0)
_, _, height, width = image.shape
if self.config.do_resize and (
height % self.config.vae_scale_factor != 0 or width % self.config.vae_scale_factor != 0
):
raise ValueError(
f"Currently we only support resizing for PIL image - please resize your pytorch tensor to be divisible by {self.config.vae_scale_factor}"
f"currently the sizes are {height} and {width}. You can also pass a PIL image instead to use resize option in VAEImageProcessor"
)
# expected range [0,1], normalize to [-1,1]
do_normalize = self.config.do_normalize
if image.min() < 0:
warnings.warn(
"Passing `image` as torch tensor with value range in [-1,1] is deprecated. The expected value range for image tensor is [0,1] "
f"when passing as pytorch tensor or numpy Array. You passed `image` with value range [{image.min()},{image.max()}]",
FutureWarning,
)
do_normalize = False
if do_normalize:
image = self.normalize(image)
return image
def postprocess(
self,
image,
output_type: str = "pil",
):
if isinstance(image, torch.Tensor) and output_type == "pt":
return image
image = self.pt_to_numpy(image)
if output_type == "np":
return image
elif output_type == "pil":
return self.numpy_to_pil(image)
else:
raise ValueError(f"Unsupported output_type {output_type}.")