Possible to "compress" stretched images?

[Leonatus]

I subscribe to the "Tagespost" magazine, whose recipe Pat Stapleton kindly created for me. It is as follows:

#!/usr/bin/env python
# vim:fileencoding=utf-8
from __future__ import unicode_literals, division, absolute_import, print_function
__license__ = 'GPL v3'
__copyright__ = '2020, Pat Stapleton <pat.stapleton at gmail.com>'
'''
Recipe for Die Tagespost
'''
from calibre.web.feeds.news import BasicNewsRecipe


class AdvancedUserRecipe1589629735(BasicNewsRecipe):
    title          = 'Tagespost'
    language       = 'de'
    __author__     = 'Pat Stapleton'
    description = ('Die Tagespost trägt den Untertitel Katholische Wochenzeitung für Politik, Gesellschaft'
        ' und Kultur und ist eine überregionale, wöchentlich im Johann Wilhelm Naumann Verlag in Würzburg erscheinende Zeitung.')
    oldest_article = 7
    max_articles_per_feed = 100
    keep_only_tags = [
        dict(name='article', attrs={'class':'art-detail'})
    ]
    use_embedded_content = False
   

    feeds          = [
        ('Tagespost', 'https://www.die-tagespost.de/storage/rss/rss/die-tagespost-komplett.xml'),
    ]
    extra_css = 'td.textb {font-size: medium;} * { text-align: justify !important; text-decoration: none !important}'
    remove_attributes = ['href']

calibre_most_common_ua = 'Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/80.0.3987.87 Safari/537.36'

I am very pleased because - unlike a previous recipe - images are also downloaded. These images naturally vary in size, but what they have in common is that they are regularly overstretched vertically. My question: Is it possible to "compress" them slightly (e.g. 25%)? A completely proportional adjustment is probably not possible.