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Killing noise - by adding pictures
Note: I rewrote most of the text for clarity, and thanks Michal for your message
Noise, especially at higher ISO numbers, is one of the biggest problems of digital imaging. While some high-end cameras like the Nikon D2X deliver low noise images even at very high ISO settings, the signal-to-noise ratio of my own default camera starts deteriorating significantly shortly above its lowest ISO number (50), resulting in visible noise. While this is overestimated in lots of use cases (noise-free photos even look unnatural), it is annoying in architecture, industry, products and still life photography.
So let's make us of so-called noise removal software like Noise Ninja, shouldn't we? Let's see how this kind of software works: first, it uses lowpass filtering to reduce the contrast of neighbouring pixels (reducing the edges), then, it uses unsharp masking to accent (sharpen) the remaing edges. This assumes that small contrasts are likely to result from noise while larger contrasts are likely to result from photographic details. It has to make such assumption as with just one metered value per pixel available, it simply cannot know what is noise and what is signal. Thus with this kind of technique, fine details are likely to get lost. Adaptive algorithms which also look at neigbouring areas help a lot here, but the problem remains: you pay with a loss of details.
Idea: Let's make use of noise's random character. If you take multiple photos with exactly the same camera settings and croppping, each photo will be different, as on each photo, the noise is distributed differently. So let's take multiple measurements of each pixel's value (take multiple "identical" photos) and average over them: as noise is random, using an average value actually improves the photo's signal to noise ratio. It grows by the square root of the number of shots taken: improvement is largest with the first additional shot and grows smaller with each additional one; doubling the signal over noise requires four extra shots, trippling nine, quadrupling 16 and so on. Just stack all your exposures onto each other in your imaging software (by using layers) and average over the additional shots by setting each layer opacity to (1/(number of layers beneath it + 1)) or 100% - 50% - 33% - 25% - 20% etc. beginning from the bottom of the stack.
Let's see what "doubling the signal over noise" (4 extra shots) looks like in real world. The (otherwise unchanged) photo was deliberately taken at a higher-than-standard ISO number (160, to add noise) and well underexposed (to have lots of low contrast details in the shadows). Details are at original size (100%).
Additive noise removal - example (S:N 1:2)
Left is one exposure, right is with four additional exposures:
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Endangered Machinery: Cathedral
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Fabric filter ← dedusting ← LD/EAF steel mill ← Ruhrstahl Henrichshütte, Hattingen, Germany
Photo taken: March 2004
Status: Closed down
Changes since: torn down
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Posted in category Endangered Machinery
Polizei im Kopf
"Durch eine zu ausgedehnte Sorgfalt des Staates leidet die Energie des Handelns überhaupt und der moralische Charakter. Wer oft und viel geleitet wird, kommt leicht dahin, den Überrest seiner Selbsttätigkeit gleichsam freiwillig zu opfern. Er glaubt sich der Sorge überhoben, die er in fremden Händen sieht, und genug zu tun, wenn er ihre Leitung erwartet und ihr folgt."
Wilhelm von Humboldt 1851
DIE ZEIT zu der spannenden Frage, warum es eigentlich keinen Aufschrei gibt, wenn der Staat die Bürgerrechte mal wieder etwas weiter einschränken will, warum Freiheit nicht wertgeschätzt wird und warum wir gar keine Gedankenpolizei brauchen, wo wir uns doch selbst haben:
Nicht der Staat ist mehr der Feind unserer Freiheit, sondern unser Sicherheitsbedürfnis →
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Erfolg in hysterischer werdenden Zeiten
Die Sheriffs der Bundesländer sollten [...] von vornherein Gesetze aufstellen, [...] die dazu dienen, die freiheitliche Grundordnung zu schützen und zu stützen, anstatt zu versuchen, mit Gummiparagraphen elementare Grundrechte auszuhöhlen.
Das Bundesverfassungsgericht hat das seit 2003 geltende hessische Telefonüberwachungs-Gesetz, das präventive Telekommunikationsüberwachung auf bloßen Verdacht hin erlaubt, praktisch in der Luft zerrissen →
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hebig.org/photos revamping
has begun →
This is ongoing design in public: things are likely to change considerably over time - reload often.
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The Hughpage
When Hugh MacLeod announced to put the Hughtrain on a wiki I wondered what he might be up to - just the Hughtrain open sourced appeared to be a bit thin. Now we know: The Hughpage - "an open-source Craigslist for bloggers":
This wiki is designed to give bloggers a place where they can centrally collate their links for whatever reason. I'll pay for the bandwidth.
Now this is either a totally great idea or a totally insane idea. Maybe a bit of both.
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And now for something completely different
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Tornado jet fighter, thrust reversers mechanism
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Hurry to work, get executed
Having a group of plainclothes policemen blowing away the head of an innocent tube passenger at point blank range in front of unsuspecting passerby just because he may or may not fit into some sort of profile is a great success for the enemy. It is hard to describe how big a disaster Britains new shoot to kill policy is. It is anything terrorists can wish for, and of zero use to not letting them win.
Also see Heiko's posting on this subject.
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Tour de France final(ly)
Today's Single Time Trail marks the last important day of this year's Tour de France. If you want to keep in touch or read back what happened so far, Oskar van Rijswijk's Pro Tour Blog has all the stage reports and all the links, Matthew Deiters offers an RSS feed of the official News Flashes, and there are Google Earth overlays for all stages - nice.
[Thanks Oskar and Matthew for your emails]
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Endangered Machinery: Corus
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Blast furnace 6, blast furnace 7, Corus Ijmuiden, The Netherlands
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Posted in category Endangered Machinery
Dein Mörder, das Opfer
Die Massenmörder von London waren keine ausgegrenzten, ungebildeten, verzweifelten Opfer brutaler rassistischer Unterdrückung, sondern nette, behütete Jungs aus normalen, anständigen Familien. Angeblich wurden sie trotzdem dazu getrieben, wahllos unbeteiligte Menschen abzuschlachten, und zwar, weil sie so arg betroffen über die schlimmen Dinge waren, die der Westen vermeintlich "den Muslimen" in Afghanistan, im Irak oder in Kaschmir angetan haben soll.
Und so langsam setzt sich die Erkenntnis durch, daß das totaler Blödsinn ist >
IM ARCHIV
2005-07-20: Fundamentalismus global
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BeebleX PHP Search Engine
BeebleX is a new web search engine specially geared towards the PHP community. It searches blogs, the php.net mailing lists, the PHP manual, PHP job sites, and you can limit your search to specific resources by prefixing it. Author Marco Tabini has an introduction.
BeebleX >
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60 Tage
Der Köhlerhorst hat also so entschieden, wie fast jeder es erwartet hat - ob da wer schon mal ein Glas Champagner aufmacht und ein paar Möbel bestellt?
ENTFERNT VERWANDT I
Werner Schulz: "Sie beschädigen das Ansehen des Parlamentes" - Rede als MP3 >
ENTFERNT VERWANDT II
Süddeutsche Zeitung: Im historischen Rückblick, was, bitte, wollen die deutschen Konservativen eigentlich? >
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Endangered Machinery: Strictement
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Parking Lot, Seraing blast furnace, Cockerill-Sambre, Liege, Belgium
Photo taken: spring 2005
Changes since: plant closed down
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Posted in category Endangered Machinery
Fundamentalismus global
Islamische Radikalisierung – wie wir sie in diesen Tagen in London und im Irak sehen – halten viele für eine Antwort traditioneller muslimischer Gesellschaften auf die Verwestlichung. [...] Diese Lesart ist falsch. [...] Der terroristische Islamismus ist keine traditionelle, sondern eine höchst moderne Glaubensrichtung. Sie wurzelt in Europa [und] entwickelt sich vor allem in der zweiten Generation der jungen Muslime in Europa. Eine Form dieses Radikalismus, den man »Dschihadismus« nennen kann, ist eine pathologische Folge der Verwestlichung des Islams.
Olivier Roy in DIE ZEIT: Wiedergeboren, um zu töten >
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Entry not found
In the beginning, blogs were celebrated as personal knowledge stores, a perception I've been sceptical of from early on - just because we have blogs, our personal storage capacity for what-to-find-where-data doesn't grow. This blog seems to have reached the point where I cannot find any given past entry just with a Google search for a specific word or two any more. One short entry on the benefits of having people with different backgrounds and perspectives on a team remains lost (but it is probably not worth spending more time with digging deeper for it).
Zooming out, bigger picture of "knowledge recalling": what knowledge applications, blogs and (even more so) wikis need is better search, better search than we have now, plus fast page and fast editor loading. Ross Mayfield calls this Rapid Recall. Speaking of wikis, where it will be of most use, he says:
It let's us simply contribute, knowing that we can recall later. Others can recall, edit it, link or tag it, and it will pop back to top of mind if it is important. We can forget when immediately processing what crosses our desk when we have confidence in rapid recall.
(The second field on which future generations of wiki tools will see vast improvements is user interfaces. Issue include: establishing as a new contributor whats already where in a wiki, establishing the context of a given wikipage, graphical mechanisms to find and connect related pages, moving towards shorter pages, and others. Have a look at Server Side Wiki, an Enterprise Wiki example page, the Socialtext products and at Wikipedia to see what wiki interfaces we have today, and how they already have progressed.)
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Endangered Machinery: Circus
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Circus on a parking lot next to Fürst Leopard colliery
Herten, Germany; May 2004
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Posted in category Endangered Machinery
Important Greasemonkey alert - Update -
Important alert for all Greasemonkey users:
Running a Greasemonkey script on a site can expose the
contents of every file on your local hard drive to that site. Running
a Greasemonkey script with "@include *" (which, BTW, is the default if
no parameter is specified) can expose the contents of every file on
your local hard drive to every site you visit. And, because
GM_xmlhttpRequest can use POST as well as GET, an attacker can quietly
send this information anywhere in the world."
Required actions: uninstall the Greasemonkey extension completely and wait for a patched version which will be due in several days, or update to Greasemonkey 0.3.5 immediately. This version has all functions relevant to the bug blocked.
Also, if you are playing with Joe Gregorio's encrypted data over insecure networks thingy, keep in mind of course to not put private keys in userscripts.
UPDATE: Simon Willison says the bug "illustrates a number of interesting concepts in both web application security and JavaScript", so he helps us Understanding the Greasemonkey vulnerability >
RELATED NEWS
Firefox 1.0.6 and Thunderbird 1.0.6 are out - download now.
IN THE ARCHIVES
2005-04-29 Improving and extending websites with Greasemonkey
2005-06-17 MT-Redland: An RDF Storage Backend for Movable Type
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Altweiß
"Malermeisterbetrieb Steppmüller?"
"Guten Tag, hier Apostolou. Ich beabsichtige meine Wohnung anstreichen zu lassen. Ich möchte Sie zu einem Pitch einladen. Wann können Sie kommen?"
"Pisch? Sie meinen Kostenvoranschlag!?" >
[via Werbeblogger]
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Endangered Machinery: Horizontal view
Click to enlarge
FACILITY: Blast furnace gas pipeline with support and gate valve, transporting gas off Europe's largest blast furnaces.ThyssenKrupp Stahl, Duisburg. Observe the stairs and railtracks to get an impression of its hefty size. If this 3-meters-plus diameter tube had a platform inside of it, you could easily drive your car through it.
HORIZONTAL VIEW: While we normally look at a specific plant and its facilities (vertical view), a horizontal view at specific elements and facilities across several plants can be quite interesting. Only then we give attention to things so ubiquitous that they and their importance normally remain unnoticed, i.e. gates, lanterns, stairs, architectural elements - and tubes and tubes knots. I will show you more of these things in future Endangered Machinery episodes.
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More Burtynsky, Kenna photography
Edward Burtynsky photographs in higher resolution than on his official site - mentioned here back in June - can be found on his Stanford University website where a Flash interface provides a zoom function. Now image these photos as 40 x 50 inches prints. The shipwrecking series is my favourite, and you should not miss Rolf Nobel's series on this subject, either. Click on Fotografie, then Abwrackwerft. Seacoalers is nice, too.
Related: Albert Renger-Patzsch was one of the pioneers of industrial photography, and Wolfgang Moersch has a small collection of early works. Mark Kenna's Ratcliffe Power Station, 1984 - 2003. Mark Kenna's The Rouge, possibly one of the best books on industrial photography ever, though out of print and not to be had below about 250€/300$. An Interview with Michael Kenna.
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Last airworthy Me 109 lost
D-FMWE, the last airworthy Messerschmidt Me 109 worldwide, has been lost in a crash landing this weekend. This is bad news, and of course it did not make it into mainstream media - just one source so far.
[via vowe]
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:: in category Aviation, Air and Space
Endangered Machinery: Hansa Coke Dry Quenching Plant demolished
The Hansa Coke CDQ (Coke Dry Quenching Plant) during one of its last nights
Click to enlarge
Demolition of Hansa Coke's Coke Dry Quenching Plant (Kokstrockenkühlung) took place July 14, 2005 at 14:30. I introduced you to this special plant back in last October - everything you can see on those past photos is gone by now. In a world where preservation of technological milestones is mainly determined by sheer age instead of technical importance, this plant of just 23 years of age has had no chance to not see its share of dynamite. There is no other plant of similar suitability for preservation and documentation than this one in Germany: Hansa Coke's CDQ was a rather small pilot plant (with full everyday use) of limited technological complexity where you could actually see how it worked when looking at it. All we can look at now is this video clip of its demolition:
Click to play video (1.5 MB)
Note that the video clip (like all my photos) is copyright protected and can be licensed - feel free to ask.
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Posted in category Endangered Machinery
Endangered Machinery: Steeler
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Steelworker handling a ladle filled with liquid converter slag
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Posted in category Endangered Machinery
Endangered Machinery: Factory Hall
I
Click to enlarge
II
Click to enlarge
III
Click to enlarge
In a former cold rolling/plate mill
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Posted in category Endangered Machinery
Endangered Machinery: Inside a steel foundry IV
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Step IV: In which we have another look at the electric arc furnace (in the moment the doors of the protective housing opened fully and the furnace roof with the electrode masts and the offgas elbow gets turned away from the shell - ready for tapping)
Prior steps: I, II, III
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Posted in category Endangered Machinery
London blast
London is being hit by a series of subway and surface explosions, the entire Tube system is shut down. This is developing news. First thoughts:
- Network attack: Most likely a coordinated attack on an infrastructure network. Either to drive it down or to observe its behaviour, not aimed at high body count. By-product: widespread confusion or panic among the public.
- Test run character: Generating a live situation in which the behaviour of infrastructure, security, rescue, communications and media networks can be observed under load. An elaborate method of gathering data points for an extended analysis of enemy networks.
- Timing: first day of G8 summit in Scotland, one day after Olympics decision. Remember Istanbul two years ago? Bombs one day before a George Bush summit.
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Gute Sache
Zeit für eine Empfehlung: 24h-bildexpress.de ist einfach klasse. Online-Printdienste gibt es wie Sand am Meer, aber das freundliche Team aus Chemnitz liefert nicht nur 1a Qualität, sondern hält die Ansage "heute bis 17 Uhr geliefert, morgen bei Ihnen" auch zuverlässig ein. Gestern nachmittag um 4 etwas hochgeladen, keine Stunde später war es bereits in der Post, und heute morgen um kurz nach 8 dann hier. Matt-Fotos werden auf schwerem Agfa Sensatis Papier gedruckt, es gibt keinen wilden Randbeschnitt oder keine ungefragt hinzugefügte "Bildoptimierung" wie bei vielen anderen Anbietern, die Farben stimmen, s/w-Fotos haben keinen Farbstich, sehr gut verpackt wird auch, und einen Schwung Gratisfotos zum Testen gibt es für Neukunden obendrein.
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Politik? Wen juckts.
Die öffentlichen Fernseher an der Uni Dortmund zum Zeitpunkt der Vertrauensfrage: Cafeteria Nord: Sat1 Soap. Cafeteria West: Viva. Cafeteria Süd: zwar Übertragung von Phoenix, auf Plasmabildschirm sogar, aber nur im Foyer und ohne Ton. Klasse Leistung. Diskussion über die Geschehnisse? Fehlanzeige. Ob das an einer Uni mit juristischer Fakultät anders ist?
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