import os
import typing as T
from collections import namedtuple
from pathlib import Path
import cv2
from PIL import Image
from tqdm import tqdm
from pycs import app
from pycs.database.File import File
DEFAULT_JPEG_QUALITY = 80
BoundingBox = namedtuple("BoundingBox", "x y w h")
Size = namedtuple("Size", "max_width max_height")
def file_info(data_folder: str, file_name: str, file_ext: str):
"""
Receive file type, frame count and frames per second.
The last two are always None for images.
:param data_folder: path to data folder
:param file_name: file name
:param file_ext: file extension
:return: file type, frame count, frames per second
"""
# determine file type
if file_ext.lower() in ['.jpg', '.png']:
file_type = 'image'
elif file_ext.lower() in ['.mp4']:
file_type = 'video'
else:
raise ValueError(f"Unsupported file extension: {file_ext}!")
# determine frames and fps for video files
if file_type == 'image':
frames = None
fps = None
else:
file_path = os.path.join(data_folder, file_name + file_ext)
video = cv2.VideoCapture(file_path)
frames = int(video.get(cv2.CAP_PROP_FRAME_COUNT))
fps = video.get(cv2.CAP_PROP_FPS)
video.release()
# return values
return file_type, frames, fps
def resize_file(file: File,
project_root: str,
max_width: int,
max_height: int) -> T.Tuple[str, str]:
"""
If file type equals video this function extracts a thumbnail first. It calls resize_image
to resize and returns the resized files directory and name.
:param file: file object
:param project_root: project root folder path
:param max_width: maximum image or thumbnail width
:param max_height: maximum image or thumbnail height
:return: resized file directory, resized file name
"""
abs_file_path = file.absolute_path
# extract video thumbnail
if file.type == 'video':
abs_target_path = os.path.join(os.getcwd(), project_root, 'temp', f'{file.uuid}.jpg')
create_thumbnail(abs_file_path, abs_target_path)
abs_file_path = abs_target_path
# resize image file
abs_target_path = os.path.join(os.getcwd(),
project_root,
'temp',
f'{file.uuid}_{max_width}_{max_height}.jpg')
resized = resize_image(abs_file_path, abs_target_path, max_width, max_height)
# return path
if resized:
return os.path.split(abs_target_path)
return os.path.split(abs_file_path)
def crop_file(file: File, project_root: str, box: BoundingBox,
max_width: int, max_height: int) -> T.Tuple[str, str]:
"""
gets a file for the given file_id, crops the according image to the
bounding box and saves the crops in the temp folder of the project.
:param file: file object
:param project_root: project root folder path
:param max_width: maximum image or thumbnail width
:param max_height: maximum image or thumbnail height
:param box: BoundingBox with relative x, y coordinates and
the relative height and width of the bounding box
:return: directory and file name of the cropped patch
"""
abs_file_path = file.absolute_path
# extract video thumbnail
if file.type == 'video':
abs_target_path = os.path.join(os.getcwd(), project_root, 'temp', f'{file.uuid}.jpg')
create_thumbnail(abs_file_path, abs_target_path)
abs_file_path = abs_target_path
bounding_box_suffix = f"{box.x}_{box.y}_{box.w}_{box.h}"
# crop image file
abs_target_path = os.path.join(os.getcwd(),
project_root,
'temp',
f'{file.uuid}_{bounding_box_suffix}.jpg')
cropped = crop_image(abs_file_path, abs_target_path, box)
if cropped:
abs_file_path = abs_target_path
# resize image
target_file_name = f'{file.uuid}_{max_width}_{max_height}_{bounding_box_suffix}.jpg'
abs_target_path = os.path.join(os.getcwd(),
project_root,
'temp',
target_file_name)
resized = resize_image(abs_file_path, abs_target_path, max_width, max_height)
if resized:
abs_file_path = abs_target_path
# return image
return os.path.split(abs_file_path)
def create_thumbnail(file_path: str, target_path: str) -> None:
"""
extract a thumbnail from a video
:param file_path: path to source file
:param target_path: path to target file
:return:
"""
# return if file exists
if os.path.exists(target_path):
return
# load video
video = cv2.VideoCapture(file_path)
# create thumbnail
_, image = video.read()
cv2.imwrite(target_path, image)
# close video file
video.release()
def resize_image(file_path: str, target_path: str, max_width: int, max_height: int) -> bool:
"""
Resize an image so width < `max_width` and height < `max_height` applies.
If the image is already smaller than the given dimensions no new file is stored.
:param file_path: path to source file
:param target_path: path to target file
:param max_width: maximum image width
:param max_height: maximum image height
:return: `True` if a resize operation was performed or the target file already exists
"""
# return if file exists
if os.path.exists(target_path):
return True
# load full size image
image = Image.open(file_path)
img_width, img_height = image.size
# abort if file is smaller than desired
if img_width < max_width and img_height < max_height:
image.close()
return False
# calculate target size
target_width = int(max_width)
target_height = int(max_width * img_height / img_width)
if target_height > max_height:
target_height = int(max_height)
target_width = int(max_height * img_width / img_height)
# resize image
resized_image = image.resize((target_width, target_height))
# save to file
resized_image.save(target_path, quality=DEFAULT_JPEG_QUALITY)
# close opened files.
image.close()
return True
def crop_image(file_path: str, target_path: str, box: BoundingBox) -> bool:
"""
Crop an image with the given coordinates, width and height.
If however no crop is applied no new file is stored.
:param file_path: path to source file
:param target_path: path to target file
:param box: BoundingBox with relative x, y coordinates and
the relative height and width of the bounding box
:return: `True` if a crop operation was performed or the target file already exists
"""
# return if file exists
if os.path.exists(target_path):
return True
# abort if no crop would be applied
if box.x <= 0 and box.y <= 0 and box.w >= 1 and box.h >= 1:
return False
# load full size image
image = Image.open(file_path)
img_width, img_height = image.size
# calculate absolute crop position
crop_x1 = int(img_width * box.x)
crop_y1 = int(img_height * box.y)
crop_x2 = min(int(img_width * box.w) + crop_x1, img_width)
crop_y2 = min(int(img_height * box.h) + crop_y1, img_height)
# crop image
cropped_image = image.crop((crop_x1, crop_y1, crop_x2, crop_y2))
# save to file
cropped_image.save(target_path, quality=DEFAULT_JPEG_QUALITY)
return True
def find_images(folder,
suffixes: T.Optional[T.List[str]] = None) -> T.List[Path]:
""" walk recursively the folder and find images """
suffixes = suffixes if suffixes is not None else [".jpg", ".jpeg", ".png"]
images: T.List[Path] = []
for root, _, files in os.walk(folder):
for file in files:
fpath = Path(root, file)
if fpath.suffix.lower() not in suffixes:
continue
images.append(fpath)
return images
def generate_thumbnails(project: "Project", sizes = None):
""" generates thumbnails for all image files in the given """
if sizes is None:
sizes = [Size(200, 200), Size(2000, 1200)]
app.logger.info(f"Generating thumbnails for project \"{project.name}\"")
files = list(project.files)
for file in tqdm(files):
for size in sizes:
resize_file(file,
project.root_folder,
size.max_width,
size.max_height)