The transformation s = T(r) producing a gray level s for each pixel value r of input image. Then, if the T(r) is monotonically increasing in interval 0 r 1, what does it signifies?

• A. tIt guarantees the existence of inverse transformation
• B. tIt is needed to restrict producing of some inverted gray levels in output
• C. tIt guarantees that the output gray level and the input gray level will be in same range
• D. tAll of the mentioned