InvokeAI/invokeai/backend/image_util/util.py

222 lines
7.4 KiB
Python

from math import ceil, floor, sqrt
from typing import Optional
import cv2
import numpy as np
from PIL import Image
class InitImageResizer:
"""Simple class to create resized copies of an Image while preserving the aspect ratio."""
def __init__(self, Image):
self.image = Image
def resize(self, width=None, height=None) -> Image.Image:
"""
Return a copy of the image resized to fit within
a box width x height. The aspect ratio is
maintained. If neither width nor height are provided,
then returns a copy of the original image. If one or the other is
provided, then the other will be calculated from the
aspect ratio.
Everything is floored to the nearest multiple of 64 so
that it can be passed to img2img()
"""
im = self.image
ar = im.width / float(im.height)
# Infer missing values from aspect ratio
if not (width or height): # both missing
width = im.width
height = im.height
elif not height: # height missing
height = int(width / ar)
elif not width: # width missing
width = int(height * ar)
w_scale = width / im.width
h_scale = height / im.height
scale = min(w_scale, h_scale)
(rw, rh) = (int(scale * im.width), int(scale * im.height))
# round everything to multiples of 64
width, height, rw, rh = (x - x % 64 for x in (width, height, rw, rh))
# no resize necessary, but return a copy
if im.width == width and im.height == height:
return im.copy()
# otherwise resize the original image so that it fits inside the bounding box
resized_image = self.image.resize((rw, rh), resample=Image.Resampling.LANCZOS)
return resized_image
def make_grid(image_list, rows=None, cols=None):
image_cnt = len(image_list)
if None in (rows, cols):
rows = floor(sqrt(image_cnt)) # try to make it square
cols = ceil(image_cnt / rows)
width = image_list[0].width
height = image_list[0].height
grid_img = Image.new("RGB", (width * cols, height * rows))
i = 0
for r in range(0, rows):
for c in range(0, cols):
if i >= len(image_list):
break
grid_img.paste(image_list[i], (c * width, r * height))
i = i + 1
return grid_img
def pil_to_np(image: Image.Image) -> np.ndarray:
"""Converts a PIL image to a numpy array."""
return np.array(image, dtype=np.uint8)
def np_to_pil(image: np.ndarray) -> Image.Image:
"""Converts a numpy array to a PIL image."""
return Image.fromarray(image)
def pil_to_cv2(image: Image.Image) -> np.ndarray:
"""Converts a PIL image to a CV2 image."""
return cv2.cvtColor(np.array(image, dtype=np.uint8), cv2.COLOR_RGB2BGR)
def cv2_to_pil(image: np.ndarray) -> Image.Image:
"""Converts a CV2 image to a PIL image."""
return Image.fromarray(cv2.cvtColor(image, cv2.COLOR_BGR2RGB))
def normalize_image_channel_count(image: np.ndarray) -> np.ndarray:
"""Normalizes an image to have 3 channels.
If the image has 1 channel, it will be duplicated 3 times.
If the image has 1 channel, a third empty channel will be added.
If the image has 4 channels, the alpha channel will be used to blend the image with a white background.
Adapted from https://github.com/huggingface/controlnet_aux (Apache-2.0 license).
Args:
image: The input image.
Returns:
The normalized image.
"""
assert image.dtype == np.uint8
if image.ndim == 2:
image = image[:, :, None]
assert image.ndim == 3
_height, _width, channels = image.shape
assert channels == 1 or channels == 3 or channels == 4
if channels == 3:
return image
if channels == 1:
return np.concatenate([image, image, image], axis=2)
if channels == 4:
color = image[:, :, 0:3].astype(np.float32)
alpha = image[:, :, 3:4].astype(np.float32) / 255.0
normalized = color * alpha + 255.0 * (1.0 - alpha)
normalized = normalized.clip(0, 255).astype(np.uint8)
return normalized
raise ValueError("Invalid number of channels.")
def resize_image_to_resolution(input_image: np.ndarray, resolution: int) -> np.ndarray:
"""Resizes an image, fitting it to the given resolution.
Adapted from https://github.com/huggingface/controlnet_aux (Apache-2.0 license).
Args:
input_image: The input image.
resolution: The resolution to fit the image to.
Returns:
The resized image.
"""
h = float(input_image.shape[0])
w = float(input_image.shape[1])
scaling_factor = float(resolution) / min(h, w)
h *= scaling_factor
w *= scaling_factor
h = int(np.round(h / 64.0)) * 64
w = int(np.round(w / 64.0)) * 64
if scaling_factor > 1:
return cv2.resize(input_image, (w, h), interpolation=cv2.INTER_LANCZOS4)
else:
return cv2.resize(input_image, (w, h), interpolation=cv2.INTER_AREA)
def nms(np_img: np.ndarray, threshold: Optional[int] = None, sigma: Optional[float] = None) -> np.ndarray:
"""
Apply non-maximum suppression to an image.
If both threshold and sigma are provided, the image will blurred before the suppression and thresholded afterwards,
resulting in a binary output image.
This function is adapted from https://github.com/lllyasviel/ControlNet.
Args:
image: The input image.
threshold: The threshold value for the suppression. Pixels with values greater than this will be set to 255.
sigma: The standard deviation for the Gaussian blur applied to the image.
Returns:
The image after non-maximum suppression.
Raises:
ValueError: If only one of threshold and sigma provided.
"""
# Raise a value error if only one of threshold and sigma is provided
if (threshold is None) != (sigma is None):
raise ValueError("Both threshold and sigma must be provided if one is provided.")
if sigma is not None and threshold is not None:
# Blurring the image can help to thin out features
np_img = cv2.GaussianBlur(np_img.astype(np.float32), (0, 0), sigma)
filter_1 = np.array([[0, 0, 0], [1, 1, 1], [0, 0, 0]], dtype=np.uint8)
filter_2 = np.array([[0, 1, 0], [0, 1, 0], [0, 1, 0]], dtype=np.uint8)
filter_3 = np.array([[1, 0, 0], [0, 1, 0], [0, 0, 1]], dtype=np.uint8)
filter_4 = np.array([[0, 0, 1], [0, 1, 0], [1, 0, 0]], dtype=np.uint8)
nms_img = np.zeros_like(np_img)
for f in [filter_1, filter_2, filter_3, filter_4]:
np.putmask(nms_img, cv2.dilate(np_img, kernel=f) == np_img, np_img)
if sigma is not None and threshold is not None:
# We blurred - now threshold to get a binary image
thresholded = np.zeros_like(nms_img, dtype=np.uint8)
thresholded[nms_img > threshold] = 255
return thresholded
return nms_img
def safe_step(x: np.ndarray, step: int = 2) -> np.ndarray:
"""Apply the safe step operation to an array.
I don't fully understand the purpose of this function, but it appears to be normalizing/quantizing the array.
Adapted from https://github.com/huggingface/controlnet_aux (Apache-2.0 license).
Args:
x: The input array.
step: The step value.
Returns:
The array after the safe step operation.
"""
y = x.astype(np.float32) * float(step + 1)
y = y.astype(np.int32).astype(np.float32) / float(step)
return y