What Is Bit Depth?

Bit depth refers to the number of bits used to represent the color or grayscale information for each pixel in a digital image, display, or video. It determines the range of colors or shades that can be displayed or captured. A higher bit depth means more available colors or shades, resulting in smoother gradients and better image quality, especially in scenarios involving subtle transitions between colors.

How Bit Depth Works

• Each pixel in a digital display is represented by a combination of red, green, and blue (RGB) channels.
• The bit depth applies to each channel. For example: ①. 8-bit per channel = 2⁸ = 256 levels per channel. ②. Combining all three channels (RGB) gives 256 × 256 × 256 = 16.7 million colors (commonly referred to as "True Color"). ③. 10-bit per channel = 2¹⁰ = 1,024 levels per channel, resulting in 1.07 billion colors.
• Higher bit depth allows for more precise representation of subtle tonal differences, reducing artifacts like color banding.

Common Bit Depths

• 8-bit (Standard):Used in most consumer displays, such as standard monitors and TVs. Can handle 16.7 million colors.
• 10-bit (High Dynamic Range - HDR):Found in professional displays, high-end TVs, and HDR-capable devices. Supports 1.07 billion colors, enabling richer gradients and dynamic range.
• 12-bit and Beyond:Used in professional-grade equipment for applications like color grading, medical imaging, or cinematography. Can produce up to 68.7 billion colors (12-bit per channel).

Applications of Bit Depth

Displays: Higher bit depth improves visual quality, especially for HDR content.
Imaging: In photography and medical imaging, higher bit depth captures more detail and subtle variations.
Video Production: Professional workflows often use 10-bit or 12-bit color grading for smoother transitions and realistic visuals.

Why Bit Depth Matters

Insufficient bit depth can result in color banding, where smooth gradients appear as visible steps between colors. For HDR content, at least 10-bit depth is essential to display the wider dynamic range and color gamut.