transparent

(of a material or object) See-through, clear; having the property that light passes through it almost undisturbed, such that one can see through it clearly.

"The waters of the lake were transparent until the factory dumped waste there."

(of a system or organization) Open, public; having the property that theories and practices are publicly visible, thereby reducing the chance of corruption.

Obvious; readily apparent; easy to see or understand.

"His reasons for the decision were transparent."

Having the property of transparency, i.e. sufficiently accurate that the compressed result is perceptually indistinguishable from the uncompressed input.