What does the term "bit depth" refer to in digital imaging?

Bit depth in digital imaging is a crucial aspect as it defines the number of bits used to characterize the color and intensity of each pixel in an image. A higher bit depth allows more color detail to be exhibited, which translates to smoother gradients and more accurate color representation. For example, an image with a bit depth of 8 bits can represent 256 different colors per channel, while a 16-bit image can represent 65,536 colors per channel. This increase in color information enhances the quality of images, particularly in capturing subtleties and variations in color, which is essential in fields such as medical imaging and professional photography.

In contrast, other concepts like duration, resolution, and compression rate focus on different aspects of the digital image or video. Duration concerns the length of time for video playback, resolution deals with the number of pixels that compose the image (impacting clarity), and compression rate pertains to how much the image file size is reduced, which can affect quality but does not directly relate to how color information is represented at the pixel level. Thus, understanding bit depth is vital when evaluating the quality and detail captured in digital images.