MoonViT / image_processing_moonvit.py
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import math
import numpy as np
from PIL import Image
from typing import Optional, Union
import torch
from torchvision.transforms import functional as TF
from transformers.image_utils import ImageInput, make_list_of_images, valid_images
from transformers.image_processing_utils import BaseImageProcessor, BatchFeature
from transformers.utils import TensorType
OPENAI_DATASET_MEAN = (0.48145466, 0.4578275, 0.40821073)
OPENAI_DATASET_STD = (0.26862954, 0.26130258, 0.27577711)
class MoonViTImageProcessor(BaseImageProcessor):
model_type = "moonvit"
def __init__(
self,
patch_size: int = 14,
pad_input: bool = False,
image_mean: tuple[float, float, float] = OPENAI_DATASET_MEAN,
image_std: tuple[float, float, float] = OPENAI_DATASET_STD,
in_token_limit: int = 4096,
merge_kernel_size: list[int, int] = [2, 2],
**kwargs,
):
super().__init__(**kwargs)
self.in_token_limit = in_token_limit
self.patch_size = patch_size
self.pad_input = pad_input
self.image_mean = image_mean
self.image_std = image_std
self.merge_kernel_size = merge_kernel_size
def rescale(
self, image: Image.Image, merge_kernel_size: list[int, int] = [2, 2]
) -> Image.Image:
w, h = image.size
patch_size = self.patch_size
if (w // patch_size) * (h // patch_size) > self.in_token_limit:
scale = math.sqrt(self.in_token_limit / ((w // patch_size) * (h // patch_size)))
new_w, new_h = int(w * scale), int(h * scale)
image = image.resize((new_w, new_h), Image.Resampling.BICUBIC)
if self.pad_input:
new_w, new_h = image.size
pad_size_h = merge_kernel_size[0] * patch_size
pad_size_w = merge_kernel_size[1] * patch_size
pad_h = (pad_size_h - new_h % pad_size_h) % pad_size_h
pad_w = (pad_size_w - new_w % pad_size_w) % pad_size_w
image = TF.pad(image, (0, 0, pad_w, pad_h))
else:
new_w, new_h = image.size
new_w = new_w - new_w % patch_size
new_h = new_h - new_h % patch_size
image = TF.center_crop(image, (new_h, new_w))
w, h = image.size
if w // patch_size >= 512 or h // patch_size >= 512:
raise ValueError("Exceed pos emb")
return image
def to_tensor(self, image: Image.Image) -> torch.Tensor:
return TF.to_tensor(image.convert("RGB"))
def normalize(self, image: torch.Tensor) -> torch.Tensor:
return TF.normalize(image, self.image_mean, self.image_std)
def patchify(self, image: torch.Tensor) -> tuple[torch.Tensor, list[int, int]]:
patch_size = self.patch_size
C, H, W = image.shape
patches = image.reshape(C, H // patch_size, patch_size, W // patch_size, patch_size)
patches = patches.permute(1, 3, 0, 2, 4)
patches = patches.contiguous().view(-1, C, patch_size, patch_size)
grid_hw = (H // patch_size, W // patch_size)
return patches, grid_hw
def _preprocess(self, image: ImageInput) -> tuple[torch.Tensor, list[int, int]]:
"""
Preprocess image and patchify it.
Args:
image (`ImageInput`):
Image to preprocess. Expects pixel values ranging from 0 to 255. If pixel values range from 0 to 1, set `do_rescale=False`.
Returns:
patches: torch.Tensor
grid_hw: list[int, int]
"""
image = self.rescale(image, self.merge_kernel_size)
image = self.to_tensor(image)
image = self.normalize(image)
patches, grid_hw = self.patchify(image)
return patches, grid_hw
def preprocess(
self,
images: ImageInput,
return_tensors: Optional[Union[str, TensorType]] = None,
) -> BatchFeature:
images = make_list_of_images(images)
if not valid_images(images):
raise ValueError(
"Invalid image type. Must be of type PIL.Image.Image, numpy.ndarray, "
"torch.Tensor, tf.Tensor or jax.ndarray."
)
pixel_values, image_grid_hws = [], []
for image in images:
patches, image_grid_hw = self._preprocess(image)
pixel_values.append(patches)
image_grid_hws.append(image_grid_hw)
pixel_values = torch.concat(pixel_values, dim=0)
image_grid_hws = np.array(image_grid_hws)
data = {"pixel_values": pixel_values, "image_grid_hws": image_grid_hws}
return BatchFeature(data=data, tensor_type=return_tensors)