Author: Wayne Rasband (wsr at nih.gov) History: 2001/11/05: First version
2008/10/14: Works with stacks; displays pixel counts if fewer than 65 colors
Source: Color_Counter.java Installation: Download Color_Counter.class to the plugins folder and restart ImageJ. Description: This plugin counts the number of unique colors in an RGB image or stack. Displays the pixel count for each color if there are no more than 64 colors.