red green blue exponent (HDRI) (RGBE)

The RGBE file format, which stands for Red, Green, Blue, Exponent, is a graphical file format used in High Dynamic Range Images( HDRI), which are photos with high dynamic range and brilliant colors.

The RGBE file format includes 4 bytes, one byte each for red, green, and blue, and the fourth byte for a common exponent for all colors. This notation is used for custom floating point representations of pixel values, using 8 bits for the exponent and another 8 bits for the mantissa (`8^8`). The colors of the RGBE file format correlate with the RGB color model and the respective color value. A direct conversion from the RGB color model to RGBE is possible. A comparable file format, which also works with an exponent, is the XYZE file format.