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(To Appear in the Proceedings of SIGGRAPH 2005)
Abstract, via Slashdot:
We present a novel photographic technique called dual photography, which exploits Helmholtz reciprocity to interchange the lights and cameras in a scene. With a video projector providing structured illumination, reciprocity permits us to generate pictures from the viewpoint of the projector, even though no camera was present at that location. The technique is completely image-based, requiring no knowledge of scene geometry or surface properties, and by its nature automatically includes all transport paths, including shadows, interreflections and caustics. In its simplest form, the technique can be used to take photographs without a camera; we demonstrate this by capturing a photograph using a projector and a photo-resistor. If the photo-resistor is replaced by a camera, we can produce a 4D dataset that allows for relighting with 2D incident illumination. Using an array of cameras we can produce a 6D slice of the 8D reflectance field that allows for relighting with arbitrary light fields. Since an array of cameras can operate in parallel without interference, whereas an array of light sources cannot, dual photography is fundamentally a more efficient way to capture such a 6D dataset than a system based on multiple projectors and one camera. As an example, we show how dual photography can be used to capture and relight scenes.
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ABC News reports:
Russia’s Defence Minister Sergei Ivanov says he is sure the Air Force will repel any hostile clouds looking to rain on next week’s Victory Day parade.
Russian pilots are past masters at seeding clouds to make rain fall away from major state events, and Mr Ivanov says they will repeat the feat for the Red Square party celebrating the 60th anniversary of the Allied victory over Nazi Germany.
The party is due to be attended by more than 50 world statesmen and Mr Ivanov says he will guarantee it will be held under a clear sky.
“Only the Defence Ministry can physically ensure a clear sky,” he said in an interview with official daily Rossiskaya Gazeta to be published on Wednesday.
However, Russian meteorologists have suggested his pilots might be up against it, amid predictions of rain for the weekend and most of next week.
The Sunday Times (Britain) reprints:
SECRET AND STRICTLY PERSONAL - UK EYES ONLY
DAVID MANNING
From: Matthew Rycroft
Date: 23 July 2002
S 195 /02
cc: Defence Secretary, Foreign Secretary, Attorney-General, Sir Richard Wilson, John Scarlett, Francis Richards, CDS, C, Jonathan Powell, Sally Morgan, Alastair Campbell
IRAQ: PRIME MINISTER’S MEETING, 23 JULY
Copy addressees and you met the Prime Minister on 23 July to discuss Iraq.
This record is extremely sensitive. No further copies should be made. It should be shown only to those with a genuine need to know its contents.
John Scarlett summarised the intelligence and latest JIC assessment. Saddam’s regime was tough and based on extreme fear. The only way to overthrow it was likely to be by massive military action. Saddam was worried and expected an attack, probably by air and land, but he was not convinced that it would be immediate or overwhelming. His regime expected their neighbours to line up with the US. Saddam knew that regular army morale was poor. Real support for Saddam among the public was probably narrowly based.
C reported on his recent talks in Washington. There was a perceptible shift in attitude. Military action was now seen as inevitable. Bush wanted to remove Saddam, through military action, justified by the conjunction of terrorism and WMD. But the intelligence and facts were being fixed around the policy. The NSC had no patience with the UN route, and no enthusiasm for publishing material on the Iraqi regime’s record. There was little discussion in Washington of the aftermath after military action.
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