Explanation:
“Pixel” is a contraction for “picture element.”
A digital image can be described through multiple formats. In the case of RGB pixels, each pixel corresponds to three 8-bit binary values. A binary value of 00000000 usually indicates no intensity of the associated colors (red, green, or blue), whereas 11111111 indicates maximum intensity of that color. The intensity of the color used in pixel rendering is according to its binary value.*
A pixel coded with three 8-bit color values reflects a portion of the image. The proportion of the image that this represents varies based on resolution, which is usually denoted by the number of horizontal or vertical pixels. For example, an image having 4096 pixels in width and 3072 pixels in height would comprise around 12.6 million samples. Some coding systems relate pixel size to linear measurements: 160 pixels per inch implies that the aforementioned image would be rendered at 25.6 inches wide and 19.2 inches tall. Depending on the rendering device, pixels may not always be square (resolution can be different in each direction).
Light entering the camera is sampled by circuits sensitive to different colors. These circuits' outputs are digitized and properly combined to ensure that for a given pixel, the RGB values correspond to the same spatial location in the image.
In a rendering device, various processes that create color are synchronized (registered) to ensure that the red, green, and blue values merge correctly at the accurate image position. Additional processing might be done to accommodate the color-rendering capabilities of the device utilized, aiming to ensure that the colors produced closely match those from the original scene captured by the camera.
In brief, the process of representing pixels in a scene involves binary values that denote the red, green, and blue (RGB) color components, which are interpreted by a rendering device (such as a display or printer) to replicate the original colors as faithfully as possible.
