What represents an image's brightness and color in digital imaging?

The correct choice indicates that pixel value represents an image's brightness and color in digital imaging. Each pixel in a digital image is made up of a specific value that corresponds to its color and brightness. This value is typically expressed in color channels (like red, green, and blue in RGB) and can vary in terms of intensity. A higher pixel value indicates a brighter pixel, and the combination of these values across an image defines its overall color and luminosity.

Other concepts like color depth refer to the number of bits used to represent a color of a single pixel, affecting how many distinct colors can be represented rather than indicating the specific brightness and color of each pixel. Pixel density focuses on how many pixels are present in a given area, influencing sharpness and detail without directly representing brightness or color. Image resolution refers to the dimensions of an image in pixels (width x height) and is related to detail and clarity but does not define brightness or color values for individual pixels.