4bitsperchannel

4bitsperchannel refers to a color representation in which each color component—red, green, and blue—is encoded with 4 bits. With 4 bits per channel, each channel has 16 possible values, yielding 16 × 16 × 16 = 4096 distinct colors in an RGB color space. The per-pixel storage is 12 bits, often stored in a 16-bit word with unused bits or padding depending on the format.

In practice, 4bpc is uncommon in modern image and display systems, which typically use 8 bits per channel (24-bit color) or higher for HDR workflows. Historically, some early computer graphics, embedded devices, or retro-style assets used 4bpc to reduce memory bandwidth and storage requirements. When used, pixel data may be packed as 12 bits per pixel, or stored as a 16-bit value with the extra bits unused or reserved, and sometimes mapped through a palette.

Advantages of 4bpc include lower memory usage and simpler hardware design, which can be important for constrained systems. The main disadvantages are limited color resolution and noticeable banding in gradients, along with reduced tonal fidelity. Dithering can mitigate some artifacts but cannot fully compensate for the limited color depth.

Although largely superseded by higher bit depths, 4bitsperchannel remains relevant in historical contexts, constrained-device graphics, and discussions of color depth trade-offs. It also serves as a reference point for understanding how increasing per-channel precision impacts color accuracy and memory requirements.

See also: color depth, RGB color model, 12-bit color, 8-bit color, dithering, palette-based images.