Emily Strickland emilyst

Image stacking is a collection of related techniques used in astrophotography which all use multiple images taken by a camera to achieve a more detailed photo than would otherwise be possible. I’ve talked about image stacking in the past, but I hand-waved the statistical parts a bit. In this post, I want to dig into those mathematical details so that you understand why image stacking actually works.

But first, I’ll tell a story about thermometers. We’ll come back to image stacking after that.

Let’s imagine you’re a scientist, and you need to know the temperature of the room you’re in to within a tenth of a degree in order to run an experiment. You dutifully order a super expensive NIST-traceable thermometer online, but on the day it arrives, you open the box only to discover that you got a hundred cheap alcohol thermometers instead.

The expensive thermometer would have done the job to within a hundredth of a degree, but now it’s too late to wait for a new one to arrive, and all you have are these che

	# /usr/local/bin/docker run --name "yt-dlp" --rm -v "/volume1/Media/Clips:/downloads:rw" jauderho/yt-dlp:latest --config-locations /downloads/yt-dlp-config

	--batch-file /downloads/to-download.txt
	--embed-chapters
	--embed-info-json
	--embed-metadata
	--embed-subs
	--embed-thumbnail
	--match-filter 'original_url!*=/shorts/'
	--mtime

	version: "3"

	services:
	db:
	image: postgres:15
	container_name: mastodon-postgres
	restart: unless-stopped
	networks:
	- internal
	sysctls:

	#!/usr/bin/env ruby

	class Hash
	def mash(prefix=nil)
	reduce({}) do \|a, (k,v)\|
	case v
	when Hash then a.merge(v.mash(k.to_s + '_'))
	else a.merge({ "#{prefix}#{k}" => v })
	end
	end

	.─────────.
	( input )
	`─────────'
	│
	▼
	┌────────────┐
	│ fps │
	└────────────┘
	│
	▼

	#!/usr/bin/env python3

	import objc
	from Foundation import (
	NSDate,
	NSDefaultRunLoopMode,
	NSLog,
	NSObject,
	NSRunLoop,
	NSThread,

	#!/usr/bin/env python3

	import threading
	# from multiprocessing import Pool
	# from multiprocessing import Process


	class EventLoopThread(threading.Thread):
	def __init__(self):
	super(EventLoopThread, self).__init__()

	#!/usr/bin/python

	from AppKit import NSWorkspace, \
	NSWorkspaceWillSleepNotification, \
	NSWorkspaceDidWakeNotification, \
	NSObject, \
	NSLog
	from PyObjCTools import AppHelper

	class NotificationHandler(NSObject):

	# /etc/sysctl.d/20-quiet-printk.conf

	kernel.printk = 3 3 3 3