#!F-adobe-helvetica-medium-r-normal--18*
#!N 
#!N  #!Rdlacoop Delayed Colors and Opacities (Color and Opacity Lookup 
Tables) #!N Delayed colors are a way of compactly storing color 
and opacity information. By default, whenever you use one of the 
coloring modules (AutoColor, AutoGrayScale, Color), the colors and opacities are stored 
one-per-data value as a floating point RGB 3-vector or floating point 
value, respectively, ranging from 0 to 1. However, if you have 
unsigned byte data, then it is much more efficient to use 
"delayed colors" and "delayed opacities." When you use delayed colors or 
opacities, the "colors" or "opacities" component is simply a copy of 
(actually a reference to) the "data" component. When rendering occurs, these 
components are interpreted as indices with which to look up a 
color or opacity value in a table. #!N #!N If you 
specify the  #!F-adobe-times-bold-r-normal--18*   delayed #!EF parameter as 1 to any of 
the coloring modules, they will automatically perform this "copy" of the 
"data" component, and will attach a "color map" or "opacity map" 
component which contains 256 RGB colors, or 256 opacities. If you 
already have a color or opacity map, either imported or created 
using the Colormap Editor, and wish to use delayed colors or 
delayed opacities, you can pass your color map or opacity map 
to the Color module as the  #!F-adobe-times-bold-r-normal--18*   color #!EF or  #!F-adobe-times-bold-r-normal--18*   
opacity #!EF parameter, and set the  #!F-adobe-times-bold-r-normal--18*   delayed #!EF parameter to 
Color as 1. #!N #!N The structure of a color map 
or opacity map is described in  #!Lcolor,dxall792 h Color  #!EL  . The Colormap Editor 
produces as its two outputs well-formed color maps and opacity maps. 
Alternatively, if you already have a simple list of 3-vectors or 
list of scalar values, and want to create a color map 
or opacity map, you can do this using Construct. The first 
parameter to Construct should be [0], the second should be [1], 
and the third should be 256. This will create a "positions" 
component with positions from 0 to 255. The last parameter to 
Construct should be your list of 256 colors or opacities. #!N 
#!N If you are reading a stored image using ReadImage, and 
the image is stored with a colormap, you can specify that 
the image should be stored internally in Data Explorer with delayed 
colors by using the  #!F-adobe-times-bold-r-normal--18*   delayed #!EF parameter to ReadImage. #!N 
#!N You can also convert an image (or object) to a 
delayed colors version by using QuantizeImage. #!N #!N #!N  #!F-adobe-times-medium-i-normal--18*   Next 
Topic #!EF #!N #!N  #!Ludcmps,dxall813 h Using Direct Color Maps  #!EL  #!N  #!F-adobe-times-medium-i-normal--18*   #!N 
