Since the development of smart phones, the pixel level of mainstream products has reached 8 million levels, such as iPhone 5, Samsung Galaxy Note 2, Xiaomi 2, Meizu MX, etc., and even several products of tens of millions of levels have appeared in the market. At present, according to the pixel level, the highest is Nokia PureView 808, which won the crown with 41 million pixels. With the continuous improvement of technology, cameras are gradually developing in the direction of high pixels. Of course, pixels are only one of the criteria to measure the shooting ability, and do not represent the overall performance of the camera, which we will mention in the next article.
By definition, pixels refer to the basic coding of basic pigments and their grayscale. Pixels can be represented by a number, for example, 300000 pixels, which represents 640 pixels horizontally and 480 pixels vertically. The total number is 640 × 480=307200 pixels, which is the traditional 300000 pixels. The larger the number of pixels, the larger the resolution of the still image taken, and the corresponding space occupied by a picture will also increase. For example, the pixel size of a traditional 6-inch photo is 1440 × 960, or 1.3 million pixels, while the number of pixels of an 8-inch photo is 3 million pixels. If you need to make a large area picture such as a poster, you need to use a larger pixel picture, otherwise it will be unclear.
Pixel also includes two concepts: "effective pixel" and "maximum pixel". The number of effective pixels refers to the pixel value that actually participates in photosensitive imaging, while the value of the maximum pixel is the real pixel of the photosensitive device. This data usually includes the non imaging part of the photosensitive device.
What are effective pixels? The effective pixel number refers to the pixel value that actually participates in photosensitive imaging. Generally, digital pictures are stored in pixels, and each pixel is the smallest unit of area in a digital picture. The larger the pixel, the larger the area of the picture. The only way to increase the area of a picture is to increase the area of the pixel if no more light enters the photosensitive device, which may affect the sharpness and clarity of the picture. When the pixel area is unchanged, the digital camera can obtain the largest picture pixel, which is the effective pixel.
The largest pixel is obtained after interpolation. The interpolation operation uses the DSP chip inside the digital device to automatically generate new pixel points by using the nearest interpolation, linear interpolation and other operation methods when the image needs to be magnified, and insert them into the gap near the original pixel, so as to achieve the purpose of increasing the total number of pixels and increasing the pixel density. For example, 2.1 million pixels can be interpolated to 4 million pixels, which depends on the interpolation method and type used by the device.
In fact, the image quality obtained after interpolation operation cannot be compared with the image of real photosensitive imaging. In practical application, there is still some gap between the picture sharpness effect taken with the largest pixel and the effect taken with the effective pixel.
At present, in domestic mobile phones, the pixel value of some products is obtained through interpolation, which is actually the largest pixel rather than the effective pixel. There is still some gap between its actual effect and the products with effective pixels. This phenomenon is more common in counterfeit mobile phones, which is not difficult to explain why the shooting effect of many counterfeit mobile phones is not enough. Of course, there are other factors that affect the shooting effect in the past. Here we only refer to the products with the largest nominal pixel.
For ordinary consumers who are not in the industry, "maximum pixel" is actually a misleading behavior. In particular, some manufacturers use the maximum pixel as an effective pixel for propaganda, which is very offensive. Consumers need to pay attention to the process of purchasing products. This phenomenon rarely occurs in the products of international first-line manufacturers, but occasionally occurs in domestic counterfeit computers. Here we should commend those manufacturers who tell the truth, such as the Big Cola mobile phone just released a few days ago. Although the 5 million effective pixel pixels are not very mainstream, at least they have not created some interpolated "high pixel cameras" to deceive consumers.
