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> Similar 48MP camera, but what are the differences, Technologies Explained

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TSDieHardHonorFan
post Jan 17 2019, 09:14 PM, updated 3y ago

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Similar 48MP camera, but what are the differences between Sony IMX586 and Samsung GM1 used by Honor View20?

Here’s a conclusion first – GM1's 48 million pixels is actually 12 million pixels in nature. Even if the phone can produce 48-megapixel photos, these are more likely achieved by interpolation. On the other hand, the IMX586 is the real traditional definition of 48 million pixels. Next, we will analyze GM1 and IMX586 from a technical perspective.

The basic principle of smartphone photography

We all know that the most important hardware for the camera is the CMOS/CCD sensor. At present, the sensor used in the smartphones is CMOS. This is a device that converts optical images into electronic signals. Whether it is a camera or a smartphone, one of the main factors in creating digital photos is the photosensitive element. At the same time, as what is defined in the name, the photosensitive element is solely sensitive to brightness but it is unable to sense the color.

If we use the photosensitive element to form an image directly, it will look like a black shadow. This is obviously not the photo we want. So, how do you get a colorful photo? At this point, I will like to introduce the concept of RGB. The RGB color model, also known as the red, green, and blue color model, is an additive color model that mixes red, green, and blue primary colors. These three colors are added together to produce a wide variety of shades. (And the red, green and blue colors cannot be synthesized with other monochromatic light).
Attached Image

Bryce Bayer, the father of digital imaging, created a color photo by adding a filter in front of the photosensitive element based on the RGB color model.

As shown in the figure below, the lower layer of gray is the photosensitive element, and each square represents a pixel block. The color above is the Bayer filter.


Attached Image

Each small square on the filter corresponds to the pixel block of the photosensitive element, in which, a specific color filter covers the front of each pixel.

For example, the leftmost red filter block allows only red light to be projected on the photosensitive element, and the corresponding pixel block only reflects the red light information.

Attached Image

Note that the above picture is a schematic diagram, there is no colour on the photosensitive element, and it only records the degree of brightness.

The Bayer filter transforms black and white to colour, but for the discerning human eyes, one colour per pixel is not enough, so it needs to go through colour restoration in order form a complete colour photo. This whole process is called as the Bayer array.

Let's have a look at the image to see how the Bayer array works:

Attached Image

The first image is the original image, and we used a 120x80 pixel sensor with a Bayer filter to shoot. The second image is the image output of the photosensitive element. As we said in the first part, the photosensitive element can only record the degree of brightness, so what we can we see is a black and white photo. The third picture is the image output after adding the Bayer filter. It shows the flower and grass; however, the image is not clear enough. The fourth picture is the image that is formed through colour reproduction. Although the pixel is too low due to hardware limitations, this is already a qualified photo.

It is not difficult to understand the general flow of digital cameras including mobile phones to take photos:

Photosensitive element → Bayer filter → Colour reproduction

This is the flow of a photo from pressing the shutter to seeing our work on screen, also known as the Bayer array.

IMX586 analysis and comparison with GM1

Firstly, pixels are the basic unit of digital display, in which the essence is an abstract sampling. In order to express it, we usually use squares to represent it. Each color block represents one pixel, and the more pixels, the better the resolution of the image.

Attached Image

The IMX586 is Sony's new stacked CMOS sensor for smartphones. This sensor has an effective pixel count of 48 million, achieving the highest level in the industry. The biggest feature of the IMX586 is the use of Quad Bayer arrays. Unlike the classic Bayer arrays, which are imaged in 2x2 four-divided RGB, the Quad Bayer array is expanded to 4x4 and RGB is arranged adjacent in 2x2. When taking photos with the IMX586 sensor smartphone, the Quad Bayer array allows each pixel to calculate the surrounding color and convert the pixel structure through independent signal processing to form a 48-megapixel HD photo in real time. In other words, the IMX586's 48 million photosensitive units can each display and output data independently. The 48-megapixel photo is directly formed through hardware and requires no software interpolation.

Through the figure below, we can clearly see the characteristics of the Quad Bayer array.

Attached Image

The output of GM1 is shown in the figure below. Although the array is also expanded to 4x4, the biggest difference from the IMX586 is that each 2x2 array can only recognize the same colour and can only form data together. In other words, the photos formed by the GM1 hardware are not essentially different from the photos formed by 12 million sensors.

Attached Image

Data disclosed by Samsung's official website can also prove this point. We can see in the specification table of GM1 that its resolution is 4000×3000, which is 12 million pixels.


Attached Image
Therefore, the fundamental difference between IMX586 and GM1 is that the former can achieve exactly 48 million pixels by transforming the pixel structure, which gives the photo a higher resolution, and it is much clearer when zooming in, which is also the outstanding feature of it.

lkwah86
post Jan 23 2019, 05:14 PM

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View 20 good?
TSDieHardHonorFan
post Jan 25 2019, 04:10 PM

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QUOTE(lkwah86 @ Jan 23 2019, 05:14 PM)
View 20 good?
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VERY HAHA
ballak
post Feb 13 2019, 12:54 PM

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so is it worth to buy view 20 because of the 48mp camera? did it come with depth mp? what about wide?
beebee1314
post Mar 29 2019, 02:57 PM

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QUOTE(DieHardHonorFan @ Jan 25 2019, 04:10 PM)
VERY HAHA
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Good to hear. Bought 27/3. Coming today.

 

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