用ENVI处理遥感影像数据的时候怎么实现HIS变换?HIS变换到底是什么样的意思

R G B颜色空间转换到 H I S颜色空间
在Transform->Color Transform->RGB to ***
RGB to HSV:Transforms an RGB image into the HSV color space.The input RGB values must be byte data in the range 0 to 255.You must have either an input file with at least three bands or a color display open to use this function.The stretch that is applied in the color display is applied to the input data.The hues produced are in the range of 0 to 360 degrees (where red is 0 degrees,green is 120 degrees,and blue is 240 degrees) and saturation and value in the range 0 to 1 (floating-point).
RGB to HLS:Transforms an RGB image into the HLS color space.The Hues produced are in the range of 0 to 360,where 0 = red,120 = green,and 240 = blue; and lightness and saturation are in the range 0 to 1 (floating-point).You must have either an input file with at least three bands or a color display open to use this function.The input RGB values must be byte data in the range 0 to 255.
再问： 木有一眼就能看到的中文么。。。。在ENVI里没找到有可以转化成HIS的工具啊。。而且我想知道HLS HSV和HIS是神马关系。。。
再答： 貌似在ENVI中HLS就是HIS illumination luminance