imageutil.java

图象编辑器

package imageapp;

import javax.swing.*;
import java.awt.*;
import java.awt.image.*;

public class ImageUtil {
	public static int[] decodeColor(int color, int rgb[]) {
		if(rgb == null) rgb = new int[3];
		rgb[0] = (color & 0x00ff0000) >> 16;
		rgb[1] = (color & 0x0000ff00) >> 8;
		rgb[2] = (color & 0x000000ff);	
		return rgb;
	}
	
	public static int encodeColor(int rgb[]) {
		int color = (255 << 24) | (rgb[0] << 16) | (rgb[1] << 8) | rgb[2];
		return color;
	}
	
	public static int getBrightness(int color) {
		int r = (color & 0x00ff0000) >> 16;
		int g = (color & 0x0000ff00) >> 8;
		int b = (color & 0x000000ff);
		int y = Math.round(0.3f*r+0.59f*g+0.11f*b);
		y = y < 0 ? 0 : y;
		y = y > 255 ? 255 : y;
		return y;
	}
	
	public static float[] convertRGBToYHS(int color, float yhs[]) {
		if(yhs == null) yhs = new float[3];
		int r = (color & 0x00ff0000) >> 16;
		int g = (color & 0x0000ff00) >> 8;
		int b = (color & 0x000000ff);	
		
		yhs[0] = (float)(0.3*r+0.59*g+0.11*b);
		double c1 = 0.7*r-0.59*g-0.11*b;
		double c2 = -0.3*r-0.59*g+0.89*b;
		yhs[2] = (float)Math.sqrt(c1*c1+c2*c2);
		if(yhs[2] < 0.005) yhs[1] = 0;
		else {
			yhs[1] = (float)Math.atan2(c1, c2);
			if(yhs[1] < 0) yhs[1] += (float)Math.PI*2;
		}
		
		
		return yhs;
	}
	
	public static int convertYHSToRGB(float yhs[]) {
		double c1 = yhs[2]*Math.sin(yhs[1]);
		double c2 = yhs[2]*Math.cos(yhs[1]);
		int r = (int)Math.round(yhs[0]+c1);
		r = r < 0 ? 0 : r;
		r = r > 255 ? 255 : r;
		int g = (int)Math.round(yhs[0]-0.3*c1/0.9-0.11*c2/0.59);
		g = g < 0 ? 0 : g;
		g = g > 255 ? 255 : g;
		int b = (int)Math.round(yhs[0]+c2);
		b = b < 0 ? 0 : b;
		b = b > 255 ? 255 : b;
		
		int color = (255 << 24) | (r << 16) | (g << 8) | b;
		return color;
	}
}