home / Problems/ Smartphone camera interpolation. What is camera interpolation in a phone and what is it for? What is camera interpolation in phone

Smartphone camera interpolation. What is camera interpolation in a phone and what is it for? What is camera interpolation in phone

A built-in camera is not the last thing when choosing a smartphone. For many, this parameter is important, so many, when looking for a new smartphone, pay attention to how many megapixels are declared in the camera. At the same time, knowledgeable people know that they are not the point. So let's take a look at what to look for when choosing a smartphone with a good camera.

How a smartphone will shoot depends on which camera module is installed in it. It looks like in the photo (the modules of the front and main cameras look about the same). It fits easily into the body of a smartphone and is usually attached with a ribbon cable. This method makes it easy to replace it in the event of a breakdown.

Sony is the monopoly on the market. It is her cameras, in the overwhelming majority, that are used in smartphones. OmniVision and Samsung are also involved in production.

The smartphone manufacturer itself is also important. In fact, a lot depends on the brand, and a self-respecting company will equip its device with a really good camera. But let's figure out what determines the quality of shooting a smartphone point by point.

CPU

Are you surprised? It is the processor that will start processing the image when it receives data from the photomatrix. No matter how high-quality the matrix is, a weak processor will not be able to process and transform the information it receives from it. This applies not only to video recording in high resolution and fast frame rate change, but also to the creation of high-resolution images.

Of course, the more frames per second change, the greater the load on the processor.

Among people who understand phones, or think that they understand, there is an opinion that smartphones with American Qualcomm processors shoot better than smartphones based on Taiwanese MediaTek processors. I will not refute or confirm this. Well, the fact that there are no smartphones with excellent cameras on low-performance Chinese Spreadtrum processors, as of 2016, is already a fact.

Megapixels

The picture consists of pixels (dots), which are formed by the photomatrix during shooting. Of course, the more pixels, the better the image should be, the higher its clarity. In cameras, this parameter is indicated as megapixels.

Megapixels (Mp, Mpx, Mpix) is a measure of the resolution of photos and videos (number of pixels). One megapixel equals one million pixels.

Take, for example, the Fly IQ4516 Tornado Slim smartphone. It shoots photos at a maximum resolution of 3264x2448 pixels (3264 color dots in width and 2448 in height). We multiply 3264 beeps by 2448 beeps, it turns out 7,990,272 pixels. The number is large, therefore it is translated into the meaning of Mega. That is, the number of 7,990,272 pixels is approximately 8 million pixels, that is, 8 megapixels.

In theory, more squeaks means a clearer picture. But do not forget about noise, about the deterioration of shooting in low light, etc.

Interpolation

Unfortunately, many Chinese smartphone manufacturers do not hesitate to programmatically increase the resolution. This is called interpolation. When the camera can take a picture at a maximum resolution of 8 megapixels, and it is programmatically increased to 13 megapixels. Of course, the quality is better not to become. How not to be deceived in such a case? Search the Internet for information on which camera module is used in your smartphone. In the characteristics of the module, it is indicated in what resolution it shoots. If you have not found information about the module, there is already a reason to be wary. Sometimes the characteristics of a smartphone can honestly indicate that the camera is interpolated, for example, from 13 megapixels to 16 megapixels.

Software

Don't underestimate software that handles digital image and presenting it to us in the final form as we see it on the screen. It detects color reproduction, removes noise, provides image stabilization (when the smartphone in the hand twitches when shooting), etc. Not to mention the various shooting modes.

Camera matrix

The type of matrix (CCD or CMOS) and its size are important. It is she who captures the image and transfers it to the processor for processing. The resolution of the camera depends on the matrix.

Aperture (aperture)

When choosing a smartphone with a good camera, you should pay attention to this parameter. Roughly speaking, it indicates how much light the matrix receives through the optics of the module. The bigger, the better. Less set - more noise. The aperture is denoted by the letter F followed by a slash (/). After the slash, the aperture value is indicated, and the smaller it is, the better. As an example, it is indicated like this: F / 2.2, F / 1.9. Often quoted in technical characteristics smartphone.

A camera with an f / 1.9 aperture will shoot better in low light than a camera with an f / 2.2 aperture, since it has more light on the sensor. But stabilization is also important in this case, both software and optical.

Optical stabilization

Smartphones are rarely equipped with optical stabilization. As a rule, these are expensive devices with an advanced camera. Such a device can be called a camera phone.

Shooting with a smartphone is carried out with a moving hand and optical stabilization is used to prevent blurring of the image. There may be hybrid stabilization (software + optical). Optical stabilization is especially important at long shutter speeds, when, due to insufficient illumination, a picture can be taken for 1-3 seconds in a special mode.

Flash

The flash can be LED and xenon. The latter will provide much the best photos in the absence of light. There is a dual LED flash. Rarely, but there may be two: LED and xenon. This is the most the best way... Implemented in the Samsung M8910 Pixon12 camera phone.

As you can see, how the smartphone will shoot depends on many parameters. So when choosing, in the characteristics, you should pay attention to the name of the module, aperture, the presence optical stabilization... It is best to search the Internet for reviews of a particular phone, where you can see examples of pictures, as well as the author's opinion on the camera.

Market mobile phones filled with models with cameras with huge resolutions. Even relatively inexpensive smartphones with sensors with a resolution of 16-20 Mp. An ignorant customer is chasing a "cool" camera and prefers a phone with a higher resolution. He does not even know that he is falling for the bait of marketers and salespeople.

What is permission?

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

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

What is phone camera interpolation?

Camera interpolation is an artificial increase in the resolution of an image. That is, images, not That is, this is special software, thanks to which a picture with a resolution of 8 megapixels is interpolated to 13 megapixels or more (or less).

By analogy, camera interpolation is similar to binoculars. These devices enlarge the image, but do not make it better or more detailed. So if interpolation is indicated in the specifications for the phone, then the actual resolution of the camera may be lower than stated. This is neither bad nor good, it just is.

What is it for?

Interpolation was invented to increase the size of the image, nothing more. This is now a ploy by marketers and manufacturers who are trying to sell a product. They indicate in large numbers on the advertising poster the resolution of the phone's camera and position it as an advantage or something good. Not only does resolution by itself not affect the quality of photos, it can also be interpolated.

Literally 3-4 years ago, many manufacturers were chasing the number of megapixels and different ways tried to cram them into their smartphones sensors with as much a large number... This is how smartphones appeared with cameras with a resolution of 5, 8, 12, 15, 21 megapixels. At the same time, they could take pictures like the cheapest soap dishes, but buyers, seeing the sticker "18 megapixel camera", immediately wanted to buy such a phone. With the advent of interpolation, selling such smartphones has become easier due to the possibility of artificially adding megapixels to the camera. Of course, the quality of the photo began to increase over time, but certainly not due to resolution or interpolation, but due to natural progress in terms of sensor development and software.

The technical side

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

With the help of special software, new pixels are "drawn" on the image. For example, to enlarge the image by 2 times, a new line is added after each line of pixels in the picture. Each pixel on this new line is filled with color. The fill color is calculated by a special algorithm. The very first way is to fill new line the colors of the nearest pixels. The result of such processing will be terrible, but this method requires a minimum of 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 interpolation methods and algorithms that are constantly being improved: the transition boundaries between colors are improved, the lines become more accurate and clear. It doesn't matter how all these algorithms are built. The very idea of camera interpolation is trivial and is unlikely to take root in the near future. Interpolation cannot make an image more detailed, add new details, or improve it in any other way. Only in movies does a small blurry picture become clear after applying a couple of filters. In practice, this cannot be.

Do you need interpolation?

Many users, unknowingly, ask questions on various forums on how to interpolate the camera, believing that this 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 due to not always accurate calculation colors for filling in the photo can be non-detailed areas, graininess. As a result, the quality drops.

So phone interpolation is a marketing gimmick 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.

Camera interpolation is an artificial increase in the resolution of an image. It is the image, not the size of the matrix. That is, this is special software, thanks to which a picture with a resolution of 8 megapixels is interpolated to 13 megapixels or more (or less). By analogy, camera interpolation is like a magnifying glass or binoculars. These devices enlarge the image, but do not make it better or more detailed. So if interpolation is indicated in the specifications for the phone, then the actual resolution of the camera may be lower than stated. This is neither bad nor good, it just is.

Literally 3-4 years ago, many manufacturers were chasing the number of megapixels and in various ways tried to cram sensors with as many sensors as possible into their smartphones. This is how smartphones appeared with cameras with a resolution of 5, 8, 12, 15, 21 megapixels. At the same time, they could take pictures like the cheapest soap dishes, but buyers, seeing the sticker "18 megapixel camera", immediately wanted to buy such a phone. With the advent of interpolation, selling such smartphones has become easier due to the possibility of artificially adding megapixels to the camera. Of course, photo quality began to improve over time, but certainly not because of resolution or interpolation, but because of natural progress in terms of sensor and software development.

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

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

Another method is most often used. That is, new lines of pixels are added to the original image. Each pixel is filled with color, which, in turn, is calculated as the average of 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. smartphone camera interpolation There are many advanced interpolation methods and algorithms that are constantly being improved: the transition boundaries between colors are improved, the lines become more accurate and clear. It doesn't matter how all these algorithms are built. The very idea of camera interpolation is trivial and is unlikely to take root in the near future. Interpolation cannot make an image more detailed, add new details, or improve it in any other way. Only in movies does a small blurry picture become clear after applying a couple of filters. In practice, this cannot be.
.html

What is camera interpolation?

Everyone has modern smartphones there are built-in cameras that allow you to enlarge the received images using special algorithms. From a mathematical point of view, interpolation is a method of detecting intermediate values of a number based on an available set of discrete parameters.

The interpolation effect is somewhat similar to the effect of a magnifying glass. Smartphone software does not increase image clarity or sharpness. It simply expands the picture to the required size. Some smartphone manufacturers write on the packaging of their products that the built-in camera has a resolution of "up to 21 megapixels". Most often, we are talking about an interpolated image, which is of low quality.

Interpolation types

Nearest Neighbor Method

The method is considered basic and belongs to the category of the simplest algorithms. Pixel parameters are determined based on one closest point. As a result of mathematical calculations, the size of each pixel is doubled. Using the nearest pixel method does not require a lot of computational power.

Bilinear interpolation

The pixel value is determined based on the data about the four nearest points captured by the camera. The result of the calculations is a weighted averaging of the parameters of the 4 pixels that surround the original point. Bilinear interpolation allows you to smooth transitions between color boundaries of objects. Images obtained using this method are significantly superior in quality to images interpolated by the nearest pixel method.

Bicubic interpolation

The color value of the desired point is calculated based on the parameters of the 16 nearest pixels. The points that are closest are given the maximum weight in the calculation. Bicubic interpolation is actively used by the software of modern smartphones and allows you to get a fairly high-quality image. Application of the method requires significant power. central processing unit and high-resolution built-in camera.

In order not to ask unnecessary questions:

Advantages and disadvantages

Science fiction films often show how a camera captures the face of a passer-by and transmits digital information to a computer. The machine enlarges the image, recognizes the photograph and finds the person in the database. In real life, interpolation does not add new detail to an image. It simply enlarges the original image using a mathematical algorithm, improving its quality to an acceptable level.

Interpolation defects

The most common defects that occur when scaling images are:

Stepping;
Blurriness;
Halo effect.

All interpolation algorithms allow maintaining a certain balance of the listed defects. Reducing the aliasing will necessarily cause an increase in image blur and halo appearance. Increasing the sharpness of the image will lead to an increase in the blurring of the picture, etc. In addition to the listed defects, interpolation can cause various graphic "noises" that can be observed at maximum magnification of the image. We are talking about the appearance of "random" pixels and textures unusual for the given subject.

Main characteristics

Matrix

Type of
The matrix installed in the webcam can be of two types: CCD and CMOS.
Traditionally, CCD is considered to provide more high quality images, better color reproduction, less noise. However, the cost of such a matrix is much higher than another type of matrix.
CMOS-matrix is manufactured according to the technology traditional for integrated circuits, so it costs less. It should be noted that modern CMOS sensors have almost caught up with their CCD counterparts in image quality.

Megapixels
from 0.1 to 16
How large quantity photosensitive elements (pixels, English pixels) are located on the matrix of the webcam, the more accurate and detailed image can be obtained.
The simplest models of webcams have a matrix of 0.1 million pixels, which allows you to get an image with a resolution of 352x288. This camera can only be used for communication via the Internet.
Cameras with a 0.3-megapixel matrix are capable of displaying 640x480 pixels. The picture when communicating via the Internet will be much better. In addition to video conferencing, such a camera can be used to shoot short videos.
Cameras with a resolution of 1.3-2 million pixels. can also be used as cameras and take photos with decent resolution.

Color depth
10 to 32 bit
The more bits are used to convey color, the more different tints the camera can display.
Cameras with 24-bit color depth (8-bit for each color) have the potential to provide excellent color reproduction. However, other parameters also affect the overall picture quality: properties of the camera lens, resolution of the photosensitive matrix, etc.
In some models of webcams, manufacturers claim to support 32-bit color.

Permission

Resolution (video)
The higher the maximum resolution of the webcam matrix in video recording mode, the more accurate and detailed the image can be obtained. Resolution - the number of dots that make up the image horizontally and vertically.
For those who plan to use a webcam only for video conferencing over the Internet, both the simplest models with a resolution of 352x288 and modifications with more high resolution 640x480.
Among modern cameras, there are also models with an even higher resolution. They can be used for video recording at home.

Resolution (photo)
Resolution refers to the number of dots that make up the image horizontally and vertically. The higher the resolution of the webcam in photography mode, the more accurate and detailed the image can be obtained.
If you plan to use your webcam in photo mode, then pay attention to models with a resolution of 1280x1024 and 1600x1200.
The photo resolution of a webcam is often higher than its resolution in video transmission mode.

Interpolated Resolution (Video)
The higher the maximum interpolated resolution of the webcam in video recording mode, the more accurate and detailed the image can be obtained. Resolution - the number of dots that make up the image horizontally and vertically.

Interpolated resolution (photo)
The higher the maximum interpolated resolution of the webcam in photo shooting mode, the more accurate and detailed the image can be obtained. Resolution - the number of dots that make up the image horizontally and vertically.
Interpolated (or artificially increased) resolution is obtained programmatically using mathematical algorithms. In this case, the amount of detail in the image remains unchanged. An interpolated resolution image usually looks slightly better than the original, but you shouldn't take high values seriously.

Interpolated megapixel resolution (photo)
from 1.2 to 20 Mpix
In some cases, manufacturers indicate not the vertical and horizontal resolution, but the number of pixels that make up the matrix with this resolution.

Frame frequency

Maximum
from 9 to 90 Hz
The maximum frame rate in video mode determines the quality of the video stream. With a slow frame rate, the image is updated not often enough and moving objects on the screen move in jerks.
At 15 frames per second, jerky movement is very noticeable on the screen; at 30 fps, the movement becomes smooth.
The frame rate in many cases depends on the resolution of the transmitted video. For example, at 352x288, a webcam is capable of generating a video stream at a frame rate of 30 Hz, while at a resolution of 640x480, the frame rate is reduced to 15 Hz.
It should be noted that the quality of the image transmitted over the Internet depends not only on the webcam itself, but also on the speed and reliability of the network connection.

For 352x288
15 to 60 Hz
Maximum frame rate in video mode at 352x288 resolution (For details, see "Maximum frame rate").

For 640x480
15 to 60 Hz
Maximum frame rate in video mode at 640x480 resolution (For details, see "Maximum frame rate").

For 1280x720
8 to 90 Hz
Maximum frame rate in video mode at a resolution of 1280x720 (For details, see "Maximum frame rate").

For 1280x1024
from 6 to 30 Hz
Maximum frame rate in video mode at a resolution of 1280x1024 (For details, see "Maximum frame rate").

For 1600x1200
5 to 30 Hz
Maximum frame rate in video mode at 1600x1200 (see "Maximum frame rate" for details).

For 1920x1080
5 to 60 Hz
Maximum frame rate in video mode at 1920x1080 resolution (See "Maximum frame rate" for details).

Focusing

Automatic
The autofocus webcam delivers clear, focused images every time. For example, if, while communicating on the Internet, a person accidentally moves away from the camera and leaves the field of focus, the autofocus itself will reconfigure the optical system, and the image will be sharp again. It should be noted that most of the simplest models of webcams do not have such a function.

Manual
To get a sharp and clear image, some webcam models are equipped with a manual focus function. Have simple models the ring on the camera lens is used for this. With "advanced" cameras, focus can be adjusted directly in the program, management work devices. These models often have an automatic focusing function (see "Automatic focusing"), while manual focusing is used in cases where the automation cannot cope with the task at hand.

Zoom

Optic
4 to 10x
Some webcam models have a zoom lens.
Changing the value of the focal length leads to a visual "approach" or "removal" of the subject. The optical zoom ratio shows how many times the lens can change the scale of the shooting. The higher the number, the more options the operator using the webcam has.

Digital
from 2 to 10x
Some webcam models have a digital zoom function that allows you to magnify the image, which is equivalent to getting closer to your subject.
Digital image enlargement is performed programmatically by increasing the pixel size of the image. With a large matrix resolution, such an increase can be performed without a noticeable deterioration in image quality.
The zoom ratio shows how many times the lens can change the scale of the shooting.

Viewing angles and rotation

Lens angle of view
from 42 to 180 degrees
The angle of view of a webcam lens determines how much of the space falls into the frame. It depends on the size of the photosensitive matrix and the parameters of the camera lens.
The wide-angle lens (70-90 degree viewing angle) allows you to capture more objects without compromising image quality.

Tilt angle
from 25 to 270 degrees

Tilt angle up
15 to 60 degrees
Many models are designed with the ability to tilt the camera, which makes it possible to quickly redirect the lens in the desired direction. The larger the tilt angle, the more convenient it is to work with the camera.

Downward tilt angle
15 to 90 degrees
Many models are designed with the ability to tilt the camera, which makes it possible to quickly redirect the lens in the desired direction. The larger the tilt angle, the more convenient it is to work with the camera.

Horizontal rotation angle
from 55 to 360 degrees
Many models are designed to allow the camera to rotate horizontally while keeping the stand unchanged. Some webcams can be rotated 360 degrees around a vertical axis. The larger the angle of rotation, the more comfortable it is to work with the camera.

Functionality

Connection
To connect a webcam to a computer, USB 1.1 or USB 2.0 interfaces are used.
For USB 1.1, the maximum data transfer rate is only 12 Mbps, which usually results in the 640x480 video transfer rate being limited to 15 frames per second. USB 1.1 can be found in the simplest webcam models.
USB 2.0 provides a transmission speed of 480 Mbps, which no longer imposes tangible restrictions on the quality of the video image. For example, you can stream video at 640x480 pixels at 30 frames per second.

Wi-Fi
Webcam support Wi-Fi connections, thanks to which the user can broadcast the video on wireless network on a tablet, smartphone or computer, conduct online broadcasting and control the web-camera from the connected device.

Microphone
Depending on the model, the webcam may have a built-in microphone or an optional microphone. Some of the simplest models may not have a microphone.
If there is a built-in microphone in the webcam, the signal is transmitted via USB interface together with the video signal, so there is no need for an additional cable. The microphone sensitivity is adjusted using the program that controls the operation of the webcam.
In some cases, the webcam does not have a built-in microphone, but it comes bundled. The main disadvantage of such a microphone is that it must be separately connected to the corresponding connector. sound card computer. Sometimes cameras are equipped not with a separate microphone, but with a headset (see "Headset Included").
The simplest models may not have a microphone at all. To transfer sound, you will need to purchase a microphone or headset separately and connect this device to your sound card.

Mount on the monitor
In order to free up space on the table, many models of webcams can be mounted on the monitor using a special mount.

Mechanical tracking drive
The mechanical tracking drive rotates the camera using a special mechanism and allows you to automatically keep the user's face, which is in the camera's field of view, in the center of the transmitted image.
For many models, the face tracking function is implemented using software (see "Face tracking function"). The range within which this function works is very limited. The mechanically driven models have much better user tracking.

Snapshot button
The button on the webcam body for taking a photo is similar to the shutter button in a conventional camera. Thus, to turn a webcam into a camera, it is enough to point the lens at the subject, press a button and get a photo.

Face tracking function
The face tracking function automatically keeps the user's face in the camera's field of view in the center of the transmitted image. This simplifies the choice of camera location and improves the convenience of video conferencing.
For most models, the face tracking function is implemented using software. However, there are also cameras on the market, in which the tracking of the user's face is performed using a special drive (see "Mechanical tracking drive").

Curtain
The design provided for the presence of a shutter on the camera lens will protect the lenses from dust, and the user from accidental / unforeseen recording.

Backlight
The built-in backlight is designed to improve the image in low light conditions.

Compatibility

Windows compatible
Availability of drivers for working with operating systems from the Windows family.

MacOS compatibility
Availability of drivers for working with operating systems from the MacOS family.
The parameter will be important for those who plan to connect a webcam to Apple computer(macOS compatible). While Windows support almost all webcams, the manufacturers guarantee work with MacOS only for some.

Linux Compatibility
Availability of drivers for working with operating systems from the Linux family.
The parameter will be important for those who plan to connect a webcam to a Linux computer. While Windows support almost all webcams, manufacturers guarantee work with Linux only for some.

Compatible operating systems
Detailed list of compatible operating systems with name and version.

Additional Information

Case included
The cover will be useful for those who plan to take a webcam on trips.

Headset included
The headset is convenient to use for communication via the Internet. Headsets are often supplied with webcams that do not have a built-in microphone (see "Microphone").

Length of cable
from 0.45 to 5 m
The longer the cable connecting the webcam to the computer, the more freely you can move the webcam. If you plan on using your camera for home video filming, then a long cable will come in handy.

Dimensions (edit)

Width
from 20 to 185 mm

Height
from 15 to 236 mm
This parameter can be important for those who plan to take a webcam on trips.

Depth
from 9 to 183 mm
This parameter can be important for those who plan to take a webcam on trips.

The weight
from 23 to 350 g
This parameter can be important for those who plan to take a webcam on trips.