- unsigned long CountColours( unsigned long stopafter = (unsigned long) -1 );
- unsigned long ComputeHistogram( wxHashTable &h );
+ unsigned long CountColours( unsigned long stopafter = (unsigned long) -1 ) const;
+
+ // Computes the histogram of the image and fills a hash table, indexed
+ // with integer keys built as 0xRRGGBB, containing wxImageHistogramEntry
+ // objects. Each of them contains an 'index' (useful to build a palette
+ // with the image colours) and a 'value', which is the number of pixels
+ // in the image with that colour.
+ // Returned value: # of entries in the histogram
+ unsigned long ComputeHistogram( wxImageHistogram &h ) const;