TImagePalette

Class Description

                                                                      
  TAttImage                                                           
                                                                      
  Image attributes are:                                               
    Image Quality (see EImageQuality for the list of qualities)       
    Compression defines the compression rate of the color data in the 
                internal image structure. Speed and memory depends    
                on this rate, but not the image display itself        
                0: no compression;  100: max compression              
    Radio Flag: kTRUE  the x/y radio of the displayed image is always 
                       identical to the original image                
                kFALSE the x and y size of the displayed image depends
                       on the size of the pad                         
    Palette:    Defines the conversion from a pixel value to the      
                screen color                                          
                                                                      
  This class is used (in general by secondary inheritance)            
  by some other classes (image display).                              
                                                                      
                                                                      
  TImagePalette                                                       
                                                                      
  A class to define a conversion from pixel values to pixel color.    
  A Palette is defined by some anchor points. Each anchor point has   
  a value between 0 and 1 and a color. An image has to be normalized  
  and the values between the anchor points are interpolated.          
  All member variables are public and can be directly manipulated.    
  In most cases the default operator will be used to create a         
  TImagePalette. In this case the member arrays have to be allocated  
  by an application and will be deleted in the destructor of this     
  class.                                                              
                                                                      
  We provide few predifined palettes:                                 
                                                                      
    o gHistImagePalette - palette used in TH2::Draw("col")            
                                                                      
    o gWebImagePalette                                                
       The web palette is a set of 216 colors that will not dither or 
       shift on PCs or Macs. Browsers use this built-in palette when  
       they need to render colors on monitors with only 256 colors    
       (also called 8-bit color monitors).                            
       The 6x6x6 web palette provides very quick color index lookup   
       and can be used for good quality convertion of images into     
       2-D histograms.                                                
                                                                      
                                                                      
  TPaletteEditor                                                      
                                                                      
  This class provides a way to edit the palette via a GUI.