Researchers are developing cameras that can take digital snapshots made up of more than a billion pixels….

LAYERED LENS: To take a gigapixel image, which contains more than 1,000 times the amount of information as a megapixel image, in one snapshot requires a special setup. Here, Columbia University researchers propose a ball-shaped lens, half of which is covered by secondary relay lenses, to capture the entire image with minimal distortion.

 

Advances in technology tend to spoil us. PCs just a few years old have nothing on today’s smart phones, and, whereas megapixel images were once the state of the art in digital photography, gigapixel images (composed of at least one billion pixels, or picture elements) are beginning to show up on the Web in vivid detail.

Gigapixel images also hold tremendous potential for providing law enforcement and the military with detailed reconnaissance and surveillance information. Long-distance images taken today by satellites or unmanned aerial vehicles (UAVs) can capture detail down to a license plate number while flying at altitudes too high for these drones to be spotted from the ground. But these images provide only a narrow view, says Ravi Athale, a consultant to the Defense Advanced Research Projects Agency (DARPA) and a senior principal scientist at MITRE Corp. in McLean, Va. He likens UAV images to seeing a battlefield or city through a “soda straw” and satellite images to an injection needle.

 

Through its Advanced Wide Field of View Architectures for Image Reconstruction and Exploitation program, DARPA has for the past year been working on ways to develop a camera that can take a gigapixel-quality image in a single snapshot. This approach is novel, given that today’s gigapixel images actually consist of several megapixel-sized images pieced together digitally to provide a high level of detail over a large area. This is often done using a long-lens digital single-lens reflex (SLR) camera placed atop a motorized mount. Software controls the movement of the camera, which captures a mosaic of hundreds or even thousands of images that, when placed together, create a single, high-resolution scene that maintains its clarity even when the viewer zooms in on a specific area. DARPA plans to invest $25 million over a three-and-a-half-year period in its  program, which includes a component called Maximally scalable Optical Sensor Array Imaging with Computation (MOSAIC).

The single-snapshot approach to gigapixel digital photography has its drawbacks. The equipment is bulky, expensive and complicated. In addition, because it may take several minutes or even hours for the automated camera to shoot all of the individual images required to create the larger mosaic, lighting conditions may change and objects (cars, people, aircraft, etc.) can move into and out of the frames. And stitching together the individual images requires software that must match overlapping points—any errors must be corrected manually.

How it works?

These systems (and those like them) work quite simply in concept, but are actually quite complex. What happens is you need to mount the compact (point and shoot) camera inside the camera system. Then, simply put the camera in the position you want (mounted or sitting on the ground, etc) and you set up your shot. Remember that when you do this it is going to be a huge image, so make sure you place the camera to capture a great surrounding that adds to your image and doesn’t detract.
Once you have the camera set up you let the machine go to work, It will take photos as it rotates through a system and course and actually moves the camera into different positions and takes the photographs. Finally after the image is saved and captured you move to the computer to start editing the huge file together. Make sure you have some processing power, as this will produce 200+ images, and my MacBook Pro with 512mb video/4gb RAM gets killed with a 10 image photoshop file.

Gigapixel images allow you to capture amazing details inside an image. This allows you to zoom in and out using software online to view the picture as a whole, or the intimate details of the work. This creates a level of interaction with your images, something that is often lost online. The user can manipulate the image and create a larger or smaller image cropped to their liking to enjoy.

 

Why not use a digital camera?

Modern frame-exposure professional digital cameras have spatial resolutions ranging of 4-16 megapixels in “35mm D-SLR” formats and up to 22 megapixels for medium format backs. Using such cameras to create gigapixel images requires mosaicing hundreds of individual exposures. Alternatively, strip-sensors can be used to scan the image plane over a few seconds time. Even so, however, large format scanning backs have final image resolutions 1-2 decades below our gigapixel regime and require relatively static scenes, as does the mosaic approach, and are thus generally inappropriate for photos of traffic, people, water, and events. The single-exposure advantage is pronounced in images with crowds of people. The facial expressions of an half a stadium of fans can be captured at passport resolution in a single instant as they react to events on the field.
Using proven techniques allows artists to recreate this effect in many amazing places, from President Obama’s inauguration to the Rocky Mountains, allows for some amazing work to wow you and captivate your imagination.

 

Posted by

Hari Hara Sravan ( MGIT ECE 2ndYear)

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