PureView Technology, the secret behind the nokia's 41 megapixel camera
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Transcript of PureView Technology, the secret behind the nokia's 41 megapixel camera
PureViewOptimization & Evaluation
Techniques in Image Processing
Puru AgrawalCSE – 4TH Sem
SSIPMT - Raipur
What is a Pixel…??
It is the smallest controllable element of a picture represented
on the screen.
Pixels
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How a pixel saves information…??
Single Pixel Combination of Pixels
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Image Sensors
• An image sensor is a device that converts an optical image into an electronic signal.• Measured in number of
pixels.• Size determines the
amount of light falling on it.
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Megapixel
• A megapixel (MP or Mpix) is one million pixels.• Number of image sensor elements
of digital cameras.• Example, a camera that makes a 2048 ×
1536 pixel image is commonly said to have "3.2 megapixels“.
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Myth
• More Megapixels results in better imagesReality- Megapixel increases image size
and not quality.
• More Megapixels better focus.Reality- Focus depends on optical parts of
camera and not on sensors.
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Problems with existing digital cameras
• Poor low light performance.• Loss in quality at
digital zooming.• Low image quality.
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PureView Technology
• Developed by NOKIA inspired by the imagery system used in satellites.
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PureView
Super High Resolution
Image Sensor (41 Mpix)
Techniques like Pixel
Oversampling and
Interpolation
Good Optics and Image Processor
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High resolution image sensors
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High resolution image sensors
Mobile Phones
Digital Cameras
PureView Sensors
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Pixel Oversampling
Sampling means how many pixels are used to produce a details. Thus oversampling means combining several pixels to form one super pixel.
• Possible only when using a large image sensor.• It eliminates noise from images.• Better zooming.• Better low light pictures and videos.• Combines 7 pixels to 1 super pixel.
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Pixel Oversampling
Without Oversampling With Oversampling13
Zoom to Oversampling output graph
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Interpolation
Interpolation works by using known data to estimate values at unknown points.
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Image interpolation works in two directions, and tries to achieve a best approximation of a pixel's color and intensity based on the values at surrounding pixels. The following example illustrates how resizing / enlargement works:
Interpolation
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Zooming
Digital zoom is a method of decreasing (narrowing) the apparent angle of view of a digital photographic or video image.
Zooming in PureView
Due to large image sensors zooming results in use of only a part of the image sensor. Thus providing lossless zoom.
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Examples of PureView
Nokia 808 PureView
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Nokia Lumia 92020
Future
• PureView uses big image processors. With advancement in processors this technology will also develop.• Better Optics smaller in size will add to its utility.• Even larger image sensors will add to better
working of techniques like Pixel Oversampling and interpolation.
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Thank you…