5.4. RGBE format

Our ray-tracer can store images in the RGBE format.

RGBE stands for Red + Green + Blue + Exponent. It's an image format developed by Greg Ward, and used e.g. by Radiance. Colors in RGBE images are stored with a very good precision, while not wasting a lot of disk space. Good precision means that you may be able to expose in the image some details that were not initially visible for the human eye, e.g. by brightening some areas. Also color components are not clamped to [0; 1] range — each component can be any large number. This means that even if resulting image is too bright, and some areas look just like white stains, you can always correct the image by darkening it or applying gamma correction etc. This is especially important for images generated by path-tracer.

You can process RGBE images using various Radiance programs. You can also use RGBE images in all my programs, for example you can view them using glViewImage and you can use them as textures on VRML models.