What happens to pixel size as the digital image matrix size increases?

As the digital image matrix size increases, the pixel size decreases. This relationship is based on the principle that the same physical area is being captured with a higher number of pixels. If a given space (for example, a detector or a sensor area) is divided into a greater number of pixels, each individual pixel must occupy a smaller portion of that area.

In a digital imaging system, the total field of view remains constant, while the number of pixels increases, resulting in a finer resolution. Consequently, the dimensions of each pixel shrink, enabling more detail to be captured within the same physical dimensions of an image. This is particularly important in applications like medical imaging, where finer pixel sizes lead to better image clarity and detail, facilitating more accurate diagnoses and evaluations.

Although some may think pixel size could remain constant or vary randomly, the fundamental principle of spatial resolution in digital imaging ensures that as resolution increases (which implies more pixels), pixel size necessarily decreases.