voussoirkit/voussoirkit/imagetools.py

60 lines
1.5 KiB
Python

def fit_into_bounds(
image_width,
image_height,
frame_width,
frame_height,
only_shrink=False,
):
'''
Given the w+h of the image and the w+h of the frame,
return new w+h that fits the image into the frame
while maintaining the aspect ratio.
(1920, 1080, 400, 400) -> (400, 225)
'''
width_ratio = frame_width / image_width
height_ratio = frame_height / image_height
ratio = min(width_ratio, height_ratio)
new_width = int(image_width * ratio)
new_height = int(image_height * ratio)
if only_shrink and (new_width > image_width or new_height > image_height):
return (image_width, image_height)
return (new_width, new_height)
def rotate_by_exif(image):
'''
Rotate the image according to its exif data, so that it will display
correctly even if saved without the exif.
'''
# Thank you Scabbiaza
# https://stackoverflow.com/a/26928142
import PIL.ExifTags
for (ORIENTATION_KEY, val) in PIL.ExifTags.TAGS.items():
if val == 'Orientation':
break
try:
exif = image._getexif()
except AttributeError:
return image
if exif is None:
return image
try:
rotation = exif[ORIENTATION_KEY]
except KeyError:
return image
if rotation == 3:
image = image.rotate(180, expand=True)
elif rotation == 6:
image = image.rotate(270, expand=True)
elif rotation == 8:
image = image.rotate(90, expand=True)
return image