New camera may capture distant images without long lens

April 17, 2017

Houston, Apr 17: Scientists, including one of Indian origin, have developed a unique camera that can capture detailed images of distant objects without using a long lens, an advance that could lead to telescopes that are less bulky. The system known as SAVI – for “Synthetic Apertures for long-range, subdiffraction-limited Visible Imaging” – does not need a long lens to take a picture of a faraway object, researchers said.The prototype built by researchers reads a spot illuminated by a laser and captures the “speckle” pattern with a camera sensor.

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The prototype built by researchers reads a spot illuminated by a laser and captures the “speckle” pattern with a camera sensor.

Raw data from dozens of camera positions is fed to a computer programme that interprets it and constructs a high-resolution image.Researchers including those from Rice University in the US, built and tested the device that compares interference pat terns between multiple speckled images. Like the technique used to achieve the “Matrix” special effect, the images are taken from slightly different angles, but with one camera that is moved between shots instead of many fired in sequence. The prototype only works with coherent illumination sources such as lasers.

However, it is a step toward a SAVI camera array for use in visible light, researchers said. The speckles serve as reference beams and essentially replace one of the two beams used to create holograms, researchers said. When a laser illuminates a rough surface, the viewer sees grain-like speckles in the dot, as some of the returning light scattered from points on the surface has to go farther and throws the collective wave out of phase. The texture of a piece of paper – or even a fingerprint -is enough to cause the effect.

“Today, the technology can be applied only to coherent (laser) light,” said Ashok Veeraraghavan of Rice University.”That means you cannot apply these techniques to take pictures outdoors and improve resolution for sunlit images -as yet,” Veeraraghavan said.”With a traditional camera, the larger the physical size of the aperture, the better the resolution,” he said.

“If you want an aperture that is half a foot, you may need 30 glass surfaces to remove aberrations and create a focused spot.
This makes your lens very big and bulky,” he added. SAVI"s “synthetic aperture” sidesteps the problem by replacing a long lens with a computer programme the resolves the speckle data into an image, researchers said.

“You can capture interference patterns from a fair distance,” Veeraraghavan said. The research was published in the journal Science Advances.

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News Network
March 13,2020

Bengaluru, Mar 13: In the wake of fresh cases of Covid-19 reported in Karnataka, Infosys Foundation chairperson Sudha Murty has urged the Karnataka government to take steps to shut malls and theatres, saying the coronavirus multiplies in air-conditioned areas.

In a letter to the government, she said preventive measures should be taken to control the spread of coronovirus before it gets worse.

Murty, who also leads the State government-constituted Karnataka Tourism Task Force, said she has discussed the current situation with Chairman and Executive Director of Narayana Health, Devi Prasad Shetty.

She suggested closure of all schools and colleges with immediate effect, malls, theatres and “all air-conditioned areas where the virus multiplies”, and allow only essential services like pharmacy, grocery and petrol bunks.

“It is not scientifically proven that the virus dies in high temperature,” she said pointing to spread of the virus -- despite heat -- in peak summer in Australia and Singapore, which have “summer all 12 months”.

“I request you to vacate one government hospital with at least 500 - 700 beds for this purpose (to deal with coronavirus cases), which requires oxygen lines and pipes,” she said.

“Infosys Foundation, the philanthropic and CSR arm of software major Infosys, would do the civil work and Devi Shetty has agreed to share resources like medical equipment,” she added.

“We would like to work with the government proactively so that we can prevent this as early as possible,” Sudha Murty said.

The total number of confirmed coronavirus positive cases in Karnataka is five, including the 76-year old man from Kalaburagi who died on Tuesday night.

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Agencies
March 15,2020

Cybercriminals continue to exploit public fear of rising coronavirus cases through malware and phishing emails in the guise of content coming from the Centers for Disease Control and Prevention (CDC) in the US and World Health Organisation (WHO), says cybersecurity firm Kaspersky.

In the APAC region, Kaspersky has detected 93 coronavirus-related malware in Bangladesh, 53 in the Philippines, 40 in China, 23 in Vietnam, 22 in India and 20 in Malaysia. 

Single-digit detections were monitored in Singapore, Japan, Indonesia, Hong Kong, Myanmar, and Thailand. 

Along with the consistent increase of 2019 coronavirus cases comes the incessant techniques cybercriminals are using to prey on public panic amidst the global epidemic, the company said in a statement. 

Kaspersky also detected emails offering products such as masks, and then the topic became more commonly used in Nigerian spam emails. Researchers also found scam emails with phishing links and malicious attachments.

One of the latest spam campaigns mimics the World Health Organisation (WHO), showing how cybercriminals recognise and are capitalising on the important role WHO has in providing trustworthy information about the coronavirus.

"We would encourage companies to be particularly vigilant at this time, and ensure employees who are working at home exercise caution. 

"Businesses should communicate clearly with workers to ensure they are aware of the risks, and do everything they can to secure remote access for those self-isolating or working from home," commented David Emm, principal security researcher.

Some malicious files are spread via email. 

For example, an Excel file distributed via email under the guise of a list of coronavirus victims allegedly sent from the World Health Organisation (WHO) was, in fact, a Trojan-Downloader, which secretly downloads and installs another malicious file. 

This second file was a Trojan-Spy designed to gather various data, including passwords, from the infected device and send it to the attacker.

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Agencies
May 30,2020

The GST Council is unlikely to make major changes in the indirect tax structure at its next meeting slated mid June.

A top government source said that the Centre is not in favour of increasing tax rates on any goods or service as it could further impact consumption and demand that is already suppressed due the COVID-19 pandemic and lockdown.

It was widely expected that the GST Council could consider raising tax rates and cess on certain non-essential items to boost revenue for states and the Centre. Several states have reportedly taken an over 80-90 per cent hit in GST collections in April, the official data for which has not yet been released by the Centre.

"The need of the hour is to boost consumption and improve demand. By categorising items into essential and non-essential and then raising taxes on non-essential is not what Centre favours. But, the issue on rates and relief will be decided by the GST Council that is meeting next month," the finance ministry official source quoted above said.

The GST Council is chaired by the Union finance minister and thus the views of the Centre play out strongly in the council meetings.

However, the Council will also have to balance the expectations of the states whose revenues have nosedived after the coronavirus outbreak and wide scale disruption to businesses while they have still not been paid GST compensation since the December-January period.

To the question of wider scale job losses in the period of lockdown as businesses get widely impacted, the official said that the Finance Ministry has asked the labour ministry to collect data on job losses during Covid-19 and is constantly engaging with the ministry to oversee job losses and salary cuts.

On restrictions put on Chinese investment in India, the official clarified that no decision had yet been taken to restrict China through the Foreign Portfolio Investment (FPI) route.

Asked about monetising government debt, the official said that the issue would be looked at when we reach a stage. It has not come to that stage yet.

In the government's over Rs 20 lakh crore economic package, the official defended its structure while suggesting that comparisons with the economic packages of other countries should not be drawn as India's needs were different from others.

"We have gone in more reforms that is needed to give strength to the economy. This is required more in our country," the official source said.

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