Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Spanish scientists design a procedure for detecting shadows in satellite images

02.06.2008
Scientists from the University of Malaga have devised a procedure for accurately identifying shadows in high-resolution images captured by satellites, making it possible to obtain more precise information on streets, buildings, vehicles, crops and other elements detected from space.

The results of this research have been passed to a company in the Parque Tecnológico de Andalucía (Andalusia Technology Park) which is already applying them in satellite image processing and detection of urban changes.

The Professor of the IT Engineering School at the University of Malaga and co-author of the study, Vicente Arévalo, explained to SINC that high-resolution images provided by current satellites and planes “have opened a new era in the field of teledetection, and that resolution enhancement also means that shadows, something inherent in any image, take on special significance”.

For example, shadows fall on buildings, cars or street furniture, the researcher commented, and in an aerial photograph “it is very important to detect what is or is not a shadow to correctly identify the elements that appear in it”.

Arévalo pointed out that the identification of shadows enables the subsequent application of specific information recovery techniques, as well as the preparation of three-dimensional designs. Thanks to the shadows, IT engineers can estimate, amongst other parameters, the height of elements in a landscape, such as a house.

To carry out this study, researchers have used images captured by the QuickBird satellite, also used for capturing aerial photographs of the Google Earth virtual atlas. Images obtained with this satellite have a 60 cm/pixel resolution, i.e. 60 cm of the real terrain captured in a pixel (the smallest unit comprising a digital image, defined by its brightness and colour). Once the image has been taken, its colour components are analysed and the so-called “seeds”, small groups of pixels that have a greater probability of being shadows, are identified through circles. To these “seeds” other surrounding pixels are added which are significant statistically for detecting the shadowy areas of the photo as accurately as possible in a process in which other tools such as edge detectors are also used.

The method developed by Andalusian researchers has been successfully tested in images obtained under different lighting conditions, in both urban and rural areas. For example, in a field of olive trees, it is easy to quantify the trees and see their size more accurately if shadows are properly identified in the high resolution images.

However, scientists’ main line of work is to detect urban changes, seeing how certain areas of cities change over time. Their studies make it possible to detect things ranging from earth movements or changes in the area to discovering whether anyone has built a swimming pool on their land. “We do not judge the legality of these types of actions”, Arévalo said, but the high resolution images of areas do help the work of surveyors.

SINC Team | alfa
Further information:
http://www.plataformasinc.es

More articles from Information Technology:

nachricht Stable magnetic bit of three atoms
21.09.2017 | Sonderforschungsbereich 668

nachricht Drones can almost see in the dark
20.09.2017 | Universität Zürich

All articles from Information Technology >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: The pyrenoid is a carbon-fixing liquid droplet

Plants and algae use the enzyme Rubisco to fix carbon dioxide, removing it from the atmosphere and converting it into biomass. Algae have figured out a way to increase the efficiency of carbon fixation. They gather most of their Rubisco into a ball-shaped microcompartment called the pyrenoid, which they flood with a high local concentration of carbon dioxide. A team of scientists at Princeton University, the Carnegie Institution for Science, Stanford University and the Max Plank Institute of Biochemistry have unravelled the mysteries of how the pyrenoid is assembled. These insights can help to engineer crops that remove more carbon dioxide from the atmosphere while producing more food.

A warming planet

Im Focus: Highly precise wiring in the Cerebral Cortex

Our brains house extremely complex neuronal circuits, whose detailed structures are still largely unknown. This is especially true for the so-called cerebral cortex of mammals, where among other things vision, thoughts or spatial orientation are being computed. Here the rules by which nerve cells are connected to each other are only partly understood. A team of scientists around Moritz Helmstaedter at the Frankfiurt Max Planck Institute for Brain Research and Helene Schmidt (Humboldt University in Berlin) have now discovered a surprisingly precise nerve cell connectivity pattern in the part of the cerebral cortex that is responsible for orienting the individual animal or human in space.

The researchers report online in Nature (Schmidt et al., 2017. Axonal synapse sorting in medial entorhinal cortex, DOI: 10.1038/nature24005) that synapses in...

Im Focus: Tiny lasers from a gallery of whispers

New technique promises tunable laser devices

Whispering gallery mode (WGM) resonators are used to make tiny micro-lasers, sensors, switches, routers and other devices. These tiny structures rely on a...

Im Focus: Ultrafast snapshots of relaxing electrons in solids

Using ultrafast flashes of laser and x-ray radiation, scientists at the Max Planck Institute of Quantum Optics (Garching, Germany) took snapshots of the briefest electron motion inside a solid material to date. The electron motion lasted only 750 billionths of the billionth of a second before it fainted, setting a new record of human capability to capture ultrafast processes inside solids!

When x-rays shine onto solid materials or large molecules, an electron is pushed away from its original place near the nucleus of the atom, leaving a hole...

Im Focus: Quantum Sensors Decipher Magnetic Ordering in a New Semiconducting Material

For the first time, physicists have successfully imaged spiral magnetic ordering in a multiferroic material. These materials are considered highly promising candidates for future data storage media. The researchers were able to prove their findings using unique quantum sensors that were developed at Basel University and that can analyze electromagnetic fields on the nanometer scale. The results – obtained by scientists from the University of Basel’s Department of Physics, the Swiss Nanoscience Institute, the University of Montpellier and several laboratories from University Paris-Saclay – were recently published in the journal Nature.

Multiferroics are materials that simultaneously react to electric and magnetic fields. These two properties are rarely found together, and their combined...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

“Lasers in Composites Symposium” in Aachen – from Science to Application

19.09.2017 | Event News

I-ESA 2018 – Call for Papers

12.09.2017 | Event News

EMBO at Basel Life, a new conference on current and emerging life science research

06.09.2017 | Event News

 
Latest News

Rainbow colors reveal cell history: Uncovering β-cell heterogeneity

22.09.2017 | Life Sciences

Penn first in world to treat patient with new radiation technology

22.09.2017 | Medical Engineering

Calculating quietness

22.09.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>