Add grayscale mapping, color space conversion, hue (#131)
Add grayscale mapping, color space conversion, hue (#131)

* add grayscale mapping

* add rgb-flag

* add color hue augmentor

* some renames

* use keepdims

Also fix #129.
ppwwyyxx/tensorpack,ppwwyyxx/tensorpack,haamoon/tensorpack,haamoon/tensorpack,eyaler/tensorpack,eyaler/tensorpack,haamoon/tensorpack