• http://getfractal.com/ - kontrola HTML + CSS pro mailové zprávy (podpora v klientech)
• https://cloudconvert.com/svg-to-png - konverze SVG do PNG včetně určení velikosti
• http://b64.io/ - konverze obrázku do base64

source: https://stackoverflow.com/a/51704714

• get into the event detail pahe and add ?eventdeb=1 to the end of URL
• then from More actions menu choose Troubleshooting Info
• later use eid = eventId and organizer = calendarId
• open https://developers.google.com/calendar/api/v3/reference/events/get
• and enter eventId and calendarId (see above)
• agree all the dialogs
• voila!