Dead pixels are dots of a raster with violations. They cannot correctly convey information about the color of the image and can be found not only on smartphone screens, but also in the sensors of many digital cameras or in the RAM of video cards.
A broken pixel itself is an exclusively visual defect that does not interfere with the functionality of the device; in practice, there are practically no ideal matrices with the complete safety of all crystals. However, a damaged pixel can cause inconvenience to the smartphone owner when viewing images and video files.
It is possible to meet dead pixels in four different variations:
- Cold (extinct) – in any type of image, a black dot is transmitted, such pixels are incurable and arise due to a defect in the control layer of the matrix.
- Hot – white dots on a color image, such pixels are distinguished by an incorrect dependence of the displayed signal on the control signal.
- Dependent – the pixel gives incorrect data and at the same time depends on neighboring sections of the matrix.
- Stuck – a fixed colored dot associated with a problem in the operation of the liquid crystal matrix. Not found on OLED devices.
Why do pixels appear on a smartphone screen?
There are three main reasons why dead pixels can appear on a smartphone screen. These are manufacturing defects, the influence of third-party factors and hardware and software failures. Most of the reasons involve the impact on the crystals of the LCD substrate.
If we consider manufacturing defects, then damaged matrices in this matter can be divided into 4 types:
- There are no dead pixels at all.
- There are no critical dead pixels, other types – no more than two.
- No more than five dead pixels, no more than fifteen others.
- Faulty matrices (the number of dead pixels, in addition to five dead ones, exceeds fifteen in total).
If the problem with pixels arose as a result of a software and hardware failure, it is easy to solve it in a service center, and some are able to fix the defect at home.
With regard to the occurrence of dead pixels as a result of external influences, power failures, overheating or hypothermia of the smartphone, strong impact or falling on a hard surface, as well as proximity to a strong electromagnetic field source can have a negative effect.
Owners of LCD monitors and other equipment equipped with screens often face such a problem as dead pixels, which are a defect. The appearance of a dead pixel is always the same and does not change when the picture on the screen changes.
They come in several types: white dot, dark dot, colored dot. The first and third types can be eliminated, but the second one cannot be removed. When buying a new LCD monitor and, moreover, a used one, it is imperative to check it for dead pixels, which are very common in used models, but also in new ones.
Which monitors often have dead pixels
First of all, dead pixels are found on inexpensive Chinese-made monitors, which go on sale already with many defects, after a few weeks of active operation, defects increase.
On monitors from well-established companies, such defects are quite rare. In any case, the screen must be checked with software that detects defects. It is not always possible to visually find dead pixels, but if it is not possible to check the monitor using the program, then you need to change the image on the monitor, then you will be able to find damaged pixels that, with certain screen colors, may not be visible to the naked eye. You need to inspect the screen completely, even in the corners.
Damaged pixels are a common occurrence with LCD monitors that have been in use. They most often appear as a result of mechanical impacts on the monitor screen, shocks, pressures, falls, and after a certain period of operation.
Distinctive features of pixel art
A “pixelated” image differs from a “non-pixelated” one by technology – manual editing of the image pixel by pixel. Therefore, pixel art differs from other types of computer art in its small size, limited color palette, and (usually) lack of anti-aliasing.
Pixel graphics use only the simplest tools of raster graphics editors, such as “pencil”, “straight”, or “fill”.
The “rule of good taste” is to use the minimum number of colors; ideally, standard 16 colors available on the vast majority of video subsystems, even the earliest ones: three bits encode R, G, B signals in them and the fourth bit encodes brightness.
Advantages
- One of the easiest computer art styles to learn (a simple pixel art can be drawn without any special artistic ability).
- Requires little memory due to the use of palette formats with a small number of colors.
- Even with very poor color reproduction, the pixel pattern does not lose its expressiveness.
- The most beautiful graphic style available on systems with a limited color palette.
- Looks good on screens with sharp pixel boundaries (like LCDs).
Flaws
- Poorly tolerates automatic scaling (when you change the resolution, the picture needs to be redrawn).
- Practically inaccessible for automatic rendering systems.
- On low-quality monitors (interlaced CRTs, some LCDs with analog input), the “mesh” toning may flicker.