What is a Pixel (Picture Element)?

Pixel is the smallest homogeneous unit in a color that is part of the digital image, be it a photo, a video frame, or a graphic.

What is a Pixel in Computer Graphics?

Pixels are color dots (grayscale is a monochrome color gamut). By enlarging the digital image (zoom) on a computer screen sufficiently, you can see the pixels in the image. These are created as a series of pixels.

The sequence shows the consistency of the information provided; There is a consistent information matrix for digital use as a whole.

The area where these matrices are reflected is usually rectangular. Representation of the homogeneous pixel in terms of variation in color and density per inch, this variation is empty and defines each point by intensity by area.

In bitmap images or graphics devices, each pixel is encoded with a series of bits of a certain length (called the color depth); For example, a pixel can be encoded with one byte (8 bits) so that each pixel supports 256 variations (28 variations by repeating 2 possible values ​​in a bit taken from 8 to 8).

In true-color images, three bytes are often used to identify color; that is, we can represent a total of 224 colors that add up to 16,777,216 color options in total (32 bits are the same color as 24 bits, but there are 8 bits for transparency).

Color Modes

To convert the numerical information stored by a pixel to color, the color mode we use must be known in addition to the color’s depth and brightness (bit size of the pixel).

RGB (Red-Green-Blue) color mode allows creating a color consisting of three primary colors according to the additional mixing system. In this way, depending on the amount of each user, the results will be seen.

For example, the violet color is obtained by mixing red and blue. Different shades of violet are obtained by changing the ratio that both components interfere.

In RGB mode, it is common to use 8 bits to represent the ratio of each of the three primary components. In this way, when one of the components is 0, it means that it does not interfere with the mixture, and when it is 255 (28-1), it interferes with providing the maximum of this tone.

Most devices used with a computer (monitor, scanner) use RGB mode. A pixel reaches 8 bits (28 colors), 24 bits (224 colors) or 48 bits (240 colors), this ultimate precision value is only achieved with high-end scanners or cameras (using raw or tiff format, not jpg).

Measurement Unit

A megapixel (Mpx) is equivalent to 1 million pixels used in calculations using 1024, which is usually used instead of 1024 for prefixes, due to its compatibility with the use of the system binary.

This unit is often used to express the image resolution of digital cameras; For example, a camera capable of taking pictures at a resolution of 2048 × 1536 pixels is said to be 3.1 megapixels (2048 × 1536 = 3.145.728).

The number of megapixels the digital camera defines the size of the photos it can take and the size of the prints that can be taken, but each megapixel is distributed over an area, and so the difference between 7 and 8 megapixels is less representation than between 3 and 4 because the “x” of a compact disc recorder It is not an exponential measurement.

Digital cameras use light-sensitive electronics such as CCDs (Charge-Coupled Device) or CMOS sensors that record brightness levels according to the pixel level.

On most digital cameras, the CCD is covered with a color filter with red, green, and blue (RGB) colored regions furnished according to the Bayer filter, so each pixel sensor can record the brightness of a single primary color.

The camera adds color information from neighboring pixels using a process called de-mosaicing to create the final image.

Megapixel (Image Size on Screen)

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