linear1gamma

Linear1gamma is a term encountered in digital imaging and rendering pipelines to describe a color encoding in which the numeric values are linearly proportional to scene luminance, corresponding to a gamma transfer function with an exponent of 1.0. In effect, data labeled as linear1gamma uses no gamma correction; the encoding is the identity function.

In color management, data can reside in a linear color space (gamma 1) or in a gamma-encoded space such as sRGB (roughly gamma 2.2). Linear1gamma data preserves arithmetic relationships used by physically based rendering, lighting calculations, and compositing, because linear values combine and interpolate in a mathematically correct manner. The term is sometimes used as a label in documentation or software configurations to emphasize that no nonlinearity has been applied to the stored data.

Applications and use cases include rendering pipelines, texture sampling, compositing, and tone mapping, where maintaining linear light values simplifies shading and blending. When outputting to displays or storage formats that expect non-linear encoding, a subsequent gamma correction (for example, a transfer function close to 2.2 for sRGB) is typically applied after the linear1gamma data has been processed.

Notes and caveats: the explicit label linear1gamma is not universally standardized and may be project- or software-specific. Users should verify the intended transfer function in documentation, as misinterpreting a label could lead to incorrect color reproduction. Related topics include gamma correction, linear color space, sRGB, and transfer functions used in color management systems.

See also: Gamma correction, linear color space, sRGB, transfer function, OpenColorIO.