What is camera interpolation in the phone and what is it for?

The mobile phone market is filled with models with cameras with huge resolutions. There are even relatively inexpensive smartphones with sensors with a resolution of 16-20 megapixels. The unknowing buyer chases the "cool" camera and gives preference to the phone whose camera resolution is higher. He does not even know that he is caught with the bait of marketers and sellers.

What is resolution?

The camera resolution is a parameter that indicates the final size of the image. It determines only how much the resulting image will be large, that is, its width and height in pixels. Important: the quality of the picture does not change. The photo may turn out to be substandard, but big due to permission.

Permission does not affect the quality. It was impossible not to mention this in the context of interpolation of the smartphone's camera. Now you can go directly to the point.

What is camera interpolation in the phone?

Camera interpolation is an artificial increase in the resolution of an image. It is the image, not the size of the matrix. That is, it is a special software, thanks to which a snapshot with a resolution of 8 Mp is interpolated to 13 Mp or more (or less).

If we draw an analogy, then the camera interpolation is similar to a magnifying glass or a binocular. These devices magnify the image, but do not make it more qualitative or detailed. So if the interpolation is indicated in the characteristics of the phone, the actual resolution of the camera may be lower than the stated resolution. It's not bad and not good, it's just there.

What is it for?

Interpolation came up to increase the size of the image, nothing more. Now it's a trick of marketers and manufacturers who are trying to sell the product. They are large numbers indicate on the advertising poster the resolution of the camera phone and position it as an advantage or something good. Not only does the resolution itself not affect the quality of the photos, so it can still be interpolated.

Literally 3-4 years ago many manufacturers were chasing the number of megapixels and in different ways tried to shove them into their smartphones with as many sensors as possible. So there were smart phones with cameras with a resolution of 5, 8, 12, 15, 21 Mp. Photographing, they could at the same time as the cheapest soap dispensers, but the buyers, after seeing the sticker "Camera on 18 Mp", immediately wanted to buy such a phone. With the advent of interpolation, selling such smartphones has become easier because of the ability to artificially add megapixels to the camera. Of course, the quality of the photo has started to grow with time, but certainly not because of resolution or interpolation, but because of natural progress in terms of developing sensors and software.

Technical side

What is the camera interpolation in the phone technically, because all the text above only described the main idea?

With the help of special software, new pixels are drawn in the image. For example, to enlarge the image in 2 times after each line of pixels in the picture, a new line is added. Each pixel in this new line is filled with color. The color of the fill is calculated by a special algorithm. The very first way is to fill the new line with the colors that the nearest pixels have. The result of such processing will be awful, but this method requires a minimum of computational operations.

Most often, another method is used. That is, a new row of pixels is added to the original image. Each pixel is filled with a color, which, in turn, is calculated as the average value of the neighboring pixels. This method gives better results, but requires more computational operations.

Fortunately, modern mobile processors are fast, and in practice the user does not notice how the program is editing the image, trying to artificially increase its size.

There are many advanced methods and algorithms for interpolation, which are constantly improved: the boundaries between colors change, the lines become more precise and clear. It does not matter how all these algorithms are built. The very idea of camera interpolation is banal and is unlikely to get used to in the near future. With the help of interpolation it is impossible to make the image more detailed, add new details or improve it in any other way. Only in movies, a small blurry picture after applying a pair of filters becomes clear. In practice, this can not be.

Do you need interpolation?

Many users, in their ignorance, ask questions on different forums how to make the camera interpolation, believing that it will improve the quality of images. In fact, interpolation will not only not improve the quality of the picture, but it can even make it worse, because new pixels will be added to the photos, and because of the not always accurate calculation of the colors for the fill in the photo there may be unedited sections, granularity. As a result, the quality falls.

So interpolation in the phone is a marketing ploy that is completely unnecessary. It can increase not only the photo resolution, but also the cost of the smartphone itself. Do not fall for the tricks of sellers and manufacturers.