In recent times mobile photography has made commendable progress, especially in terms of the pixel count. Not many years ago we used to see smartphones with a 2 Mega-pixel camera while we now see 12MP sensors as a common sight even on budget smartphones. In fact we’ve now started to see a few 48 million-pixel or megapixel cameras such as the Samsung GM1 and the Sony IMX586. While there are at least these two models that claim to output a 48MP resolution image, both the sensors do it in very different ways.
To put the entire story in short, the Samsung GM1 is essentially a 12MP sensor and the supported smartphones can output a 48MP resolution image using a technique called interpolation. The IMX587, on the other hand, is a true 48MP sensor that captures all the details and uses no software gimmick. A better understanding of the difference between the two sensors can be achieved by understanding the differences a little more.
The most important hardware in a camera is the CMOS sensor or a CCD in some specific cases. Currently, most smartphones in the market make use of a CMOS sensor to capture an image. The sensor works by converting an optical image into electronic signals, the most important hardware in the sensor is the photosensitive element. While a photosensitive element, by definition, is only sensitive to light and darkness and cannot identify or sensor the different colors, essentially using a photosensitive element directly can result in a black shadow. To get a full-color image we use the concept of RGB color model, this is an additive color model that uses different colors and shades of Red, Blue and Green to generate more vivid images. These images are combined uniquely to produces a wider variety of shades.
This was first tested by Bryce Bayer who is considered as the father of digital imaging, he introduced the world to color photography in digital format by using a filter in front of the photosensitive element. A color filter called the Bayer Filter is used over each photosensitive element and each block here is treated as a pixel block for the image. Each of these photosensitive elements is covered by a specific color that is placed in front of them.
Now analyzing the difference between the IMX586 sensor and the Samsung GM1, pixels are basic display units and is expressed here in terms of squares. Each color block in the illustrations represents a pixel and the more the number pixels, the higher is the resolution of the image. The IMX 586 sensor is Sony’s new CMOS for mobile phones and has an effective pixel count of 48 million or 48 Mega-pixel. This makes it the highest level in the industry and the technical data sheet of the sensor for the mobile phone shooting with it has been completely rewritten. The IMX586’s highlight feature is the use of Bayer array and the array is different from the classic Bayer total of a 2×2 grid. The Bayer array quad has extended it to 4×4 in a way arranged adjacent to the RGB.
In use, the IMX586 Quad Bayer array calculates the pixel color of the surrounding nearby pixels and then converts by using a pixel signal processing independent structure to real-time output a total of 48 million pixels. Essentially, the photosensitive units of the IMX586 can each individually display and output data independent of the other elements and the 48MP photo is straight out of the hardware with no major software tweaking going on.
However, the output of the Samsung GM1 sensor is a little different and uses a traditional 2×2 array to recognize the same color and can only output data collectively. The photos output by the GM1 sensor is not essentially very different from the output of a 12MP sensor. The data displayed on the Samsung Official website confirms this and the specification clearly states a resolution of 4000 x 3000 adding up to 12 million pixels or 12 Mega-pixels. The rest of the work is done on the software end using pixel interpolation to theoretically come up with a 48MP resolution image. The fundamental difference between the IMX586 and the Samsung GM1 is that Sony IMX586 sensor can achieve true 48MP resolution image making the photo have a sharper resolution and the resultant images are also sharper after zooming.