RGBA4444

RGBA4444 is a 16-bit per pixel color format in which each of the red, green, blue, and alpha channels is allocated 4 bits. With 4 bits per channel, each component can take 16 discrete levels, so a single pixel has 65,536 possible color values. The four 4-bit components are packed into a 16-bit word, and the order of the channels can vary depending on the specific format (for example RGBA, ARGB, or ABGR arrangements).

Because each channel is only 4 bits wide, RGBA4444 provides reduced color precision compared with 8-bit-per-channel formats. To map the 4-bit values to standard 8-bit color values used for display, a common approach is to scale by 17 (0x11). For example, a 4-bit value of 0x0 maps to 0, and 0xF maps to 255.

RGBA4444 is used in certain graphics pipelines, textures, and image data where memory or bandwidth constraints are important. It is commonly encountered in older or embedded systems and in some texture formats supported by graphics APIs such as OpenGL and DirectX. It offers a smaller memory footprint than 32-bit formats like RGBA8888 but at the cost of color and alpha precision, which can lead to visible banding and less smooth transparency.

Variants of the 4-4-4-4 scheme include different channel orders (for instance RGBA4444, ARGB4444, or ABGR4444) depending on the hardware or API. RGBA4444 is typically compared with other 16-bit formats such as RGBA5551 and RGB565, which balance precision and memory in different ways.

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